Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: Jim Hunt on March 01, 2019, 02:41:14 PM

Title: The 2019 melting season
Post by: Jim Hunt on March 01, 2019, 02:41:14 PM
Neven still hasn't got around to opening this thread, but "Snow White" has (prematurely?) called the 2019 maximum over on Twitter:

https://twitter.com/GreatWhiteCon/status/1101471926390870016

Here's the "JAXA" version. Discuss!

<edited title to match those of precious years; N.>
Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 01, 2019, 04:25:07 PM
By way of a partial explanation for the recent rapid melt, here's a closeup of the Bering Strait area using the new CryoSat-2/SMOS gridded thickness product. It's updated weekly, and this is from February 24th:
Title: Re: The 2019 Melting Season
Post by: Juan C. García on March 01, 2019, 07:09:22 PM
Neven still hasn't got around to opening this thread, but "Snow White" has (prematurely?) called the 2019 maximum over on Twitter:

https://twitter.com/GreatWhiteCon/status/1101471926390870016

Here's the "JAXA" version. Discuss!


I like this topic on March 1st!!!  ;D
The reason is not just the day. I find it very difficult that in March we can have a new maximum in JAXA (excluding NSIDC).
Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 01, 2019, 11:33:59 PM
I find it very difficult that in March we can have a new maximum in JAXA (excluding NSIDC).

Likewise for Wipneus' high resolution daily AMSR2 area?
Title: Re: The 2019 Melting Season
Post by: jdallen on March 02, 2019, 12:11:43 AM
We have had bigger rebounds recently, but not by much.  If today shows another drop that may be it.

The only place I can see actually changing that I'd the Barents, but there the ice is fighting the highest imported heat in our history.
Title: Re: The 2019 Melting Season
Post by: Juan C. García on March 02, 2019, 12:29:56 AM
The only place I can see actually changing that I'd the Barents, but there the ice is fighting the highest imported heat in our history.
I agree. On the other hand, the heat that is coming from the Pacific is impressive (Anomaly of +5.1 °C on the Arctic).
Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 02, 2019, 12:58:34 AM
The only place I can see actually changing that I'd the Barents, but there the ice is fighting the highest imported heat in our history.

Here's the current state of play in the Barents Sea:
Title: Re: The 2019 Melting Season
Post by: be cause on March 02, 2019, 01:49:28 AM
perhaps we should have a 'betwixt and between' thread for those who anticipate a twin peak season ?
b.c,
Title: Re: The 2019 Melting Season
Post by: jdallen on March 02, 2019, 01:55:53 AM
perhaps we should have a 'betwixt and between' thread for those who anticipate a twin peak season ?
b.c,
Not needed I think. Jim's  graph pretty much demonstrates the Barents can't make up the shortfall on its own,  and the rest of the rest of the  Arctic won't be much help.
Title: Re: The 2019 Melting Season
Post by: wdmn on March 02, 2019, 04:00:25 AM
If we are into the melt then, am I right in thinking this has been quite a unique freezing season? A record slow start, followed by a rebound, and now -- potentially -- by the second (if I'm correct) earliest maximum on record.

So while extent and area have been right around the 2010s average for several months, it seems that the freezing season has shortened...
Title: Re: The 2019 Melting Season
Post by: Rod on March 02, 2019, 04:37:18 AM
This is an incredible image posted by Zack Labe on Twitter today.

https://t.co/NEfaf773PA

[Sentinel-3 satellite (2/28/2019): apps.sentinel-hub.com/eo-browser/?la…]

Rick Thoman mentioned that this image would be remarkable for Memorial Day (for non USA people, Memorial Day is the last Monday in May), let alone the end of February. 

I know when I first started following these forums I would always get confused by partial shots of the arctic. So in case anyone does not recognize this area, it is the Bering Strait.
Title: Re: The 2019 Melting Season
Post by: Rod on March 02, 2019, 06:41:06 AM
One more amazing shot of the Bering Strait.  This one was posted by Rick Thoman and shows an area near Little Diomede where there should currently be an ice runway for airplanes. 

The Bering Strait is a small part of the arctic, and it is still a little early to call the maximum.  Neven might close this thread, and he would not be wrong if he did (I tend to agree with Jim Hunt that we have seen the max, but the next two to three weeks could change things).  The loss of ice on the Pacific side over the last few days is shocking!  Maybe it will recover in the next couple of weeks and maybe not. Either way, the trend over the last few years is very troubling. 
Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 02, 2019, 07:46:00 AM
This is an incredible image posted by Zack Labe on Twitter today.

That's a very interesting thread Rod, for all sorts of reasons! For example it includes an "incredible image" from my Arctic alter ego "Snow White":

https://twitter.com/GreatWhiteCon/status/1101634642606768131

It even speaks to my new "Algorithms of Hate (http://forum.arctic-sea-ice.net/index.php/topic,2589)" thread too!

Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 02, 2019, 08:08:09 AM
Jim's  graph pretty much demonstrates the Barents can't make up the shortfall on its own,  and the rest of the rest of the  Arctic won't be much help.

Although it's perhaps not entirely beyond the bounds of possibility that the Bering area could "flash freeze" as quickly as it has "flash melted", to provide a short lived skin of sea ice substantial enough to be detectable by AMSR2?
Title: Re: The 2019 Melting Season
Post by: DavidR on March 02, 2019, 08:31:26 AM
JAXA is currently  285 K below the maximum.  About 6 years have seen increases above 250K after this date. 2018 increased over 280K between March 7th and maximum on Mar 17th after dropping 150K in the previous week. 

So we probably have seen the maximum but the winds and the weather could easily flip that.  I  agree with an earlier commentator that  Mar 1st  is a sensible day to start this thread rather than waiting until we are absolutely certain that  the max has passed.
Title: Re: The 2019 Melting Season
Post by: bbr2314 on March 02, 2019, 08:32:37 AM
Jim's  graph pretty much demonstrates the Barents can't make up the shortfall on its own,  and the rest of the rest of the  Arctic won't be much help.

Although it's perhaps not entirely beyond the bounds of possibility that the Bering area could "flash freeze" as quickly as it has "flash melted", to provide a short lived skin of sea ice substantial enough to be detectable by AMSR2?
That is what happened in 2018 resulting in a secondary max. This year one difference is that the PAC appears saltier. Also, there was a thick arm of MYI attached to the entire northern Alaskan seaboard in March 2018. This year, that arm of MYI is well out into the Beaufort, several hundred KM from shore in most spots, and open water is already appearing along the AK shoreline. For now it is refreezing for the most part, but soon, the Beaufort could also open very quickly (unlike 2018).
Title: Re: The 2019 Melting Season
Post by: Neven on March 02, 2019, 09:51:47 AM
Now where's that melt season thread ! Oops sorry Neven !

 :D

I'll open it myself if tomorrow if JAXA reports yet another drop.

JAXA has reported another drop, albeit a small one, so this one can stay open.  :)

I'll sticky it once I'm 100% sure the max has been hit.
Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 02, 2019, 10:53:13 AM
JAXA has reported another drop, albeit a small one, so this one can stay open.  :)

You are very kind Neven!

Hot off the presses at Great White Con Ivory Towers, courtesy of our private wire to the Arctische Pinguin:
Title: Re: The 2019 melting season
Post by: bbr2314 on March 02, 2019, 12:23:01 PM
It is worth noting that as the Bering melts out, the Great Lakes are actually still icing. An Arctic outbreak should ensure that this continues for the next week or more. They are on the verge of cracking the top 3 recent years for early March (1979, 1994, and 2014  -- 2015 may be on the list as well?).

We need 86% to beat 1994 and approach 2014's record, it seems very doable given expected conditions.

(https://www.glerl.noaa.gov/res/glcfs/compare_years/2019_061_glsea.png)
Title: Re: The 2019 melting season
Post by: Juan C. García on March 02, 2019, 06:09:05 PM
With ADS (JAXA) values, three years have increases above 285K km2 on March.
It is possible to have a new max on 2019, but seems difficult to me.
Let's wait and see…  ;)
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 02, 2019, 11:55:48 PM
An animation of AMSR2 concentration revealing the recent spread of open water across the southern Chukchi Sea:

http://youtu.be/6jtrVxpG7Sw
Title: Re: The 2019 melting season
Post by: sark on March 03, 2019, 12:34:39 AM
It is worth noting that as the Bering melts out, the Great Lakes are actually still icing. [...]

well yeah. https://imgur.com/a/U6nsnfw
Title: Re: The 2019 melting season
Post by: Gray-Wolf on March 03, 2019, 01:09:46 AM
I read something recently that was looking at the flooding of the strat , over the U.S.A., with water vapour from ever taller storms and have to wonder if we can rapidly alter the levels of heat trapping water in the arctic strat impeding the loss of heat from the polar night?

Is a warmed world providing a rapid path to an equable climate?
Title: Re: The 2019 melting season
Post by: aperson on March 03, 2019, 01:14:29 AM
I read something recently that was looking at the flooding of the strat , over the U.S.A., with water vapour from ever taller storms and have to wonder if we can rapidly alter the levels of heat trapping water in the arctic strat impeding the loss of heat from the polar night?

Is a warmed world providing a rapid path to an equable climate?

Definitely, although I think water vapor intruding from tropics to poles causing an equable climate is almost true by tautology. Equable climates can be defined in terms of only having a Hadley cell stretching from equator to pole instead of our 3 cell hadley, ferrel, polar cell regime.

I think what we have been witnessing in terms of Rossby wavebreak patterns transporting water vapor poleward (especially over Alaska) is a leading indicator of the 3-cell regime breaking down entirely.
Title: Re: The 2019 melting season
Post by: sark on March 03, 2019, 06:36:17 AM
Quote
[...]
I think what we have been witnessing in terms of Rossby wavebreak patterns transporting water vapor poleward (especially over Alaska) is a leading indicator of the 3-cell regime breaking down entirely.

The Hadley cell is already feeding into the polar cell

https://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-139,84,336/loc=-140,90
Title: Re: The 2019 melting season
Post by: b_lumenkraft on March 03, 2019, 08:33:35 AM
Can someone explain this?

I find it weird it would melt in the middle of the ice area. This started on the 13th of February. Correction: This seems to be a consistent feature. Seen in other years too.

I can only assume this is heat from below, but where is it coming from? Atlantic side?
Title: Re: The 2019 melting season
Post by: jdallen on March 03, 2019, 09:09:03 AM
An animation of AMSR2 concentration revealing the recent spread of open water across the southern Chukchi Sea:
<snippage>
I got curious.  This is actually pretty definitive.  The Bering (And Chukchi) ice is in worse shape this year than it was in 2018 at the same time.  Unambiguous in the images.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 03, 2019, 11:21:35 AM
Can someone explain this?

My ageing eyes are undoubtedly no longer in their prime. Maybe that explains why I cannot see what you are looking at!

Can you elucidate please?
Title: Re: The 2019 melting season
Post by: Neven on March 03, 2019, 11:36:42 AM
Can someone explain this?

My ageing eyes are undoubtedly no longer in their prime. Maybe that explains why I cannot see what you are looking at!

Can you elucidate please?

I think he means ice pulling away from the coast, caused by winds (and quickly freezing over again).
Title: Re: The 2019 melting season
Post by: b_lumenkraft on March 03, 2019, 11:40:01 AM
Of course, sorry for not being clearly enough.

There is this pronounced feature where ice is melting in the middle of the Laptev Sea.

Zoomed in link >> https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,MODIS_Terra_Sea_Ice(hidden),MODIS_Aqua_Sea_Ice(hidden,opacity=0.49),MODIS_Aqua_Brightness_Temp_Band31_Night(hidden),MODIS_Aqua_Brightness_Temp_Band31_Day(hidden),MODIS_Terra_Brightness_Temp_Band31_Day(hidden),VIIRS_SNPP_Brightness_Temp_BandI5_Day(hidden,opacity),Graticule,Coastlines,Reference_Features,Reference_Labels,VIIRS_SNPP_DayNightBand_ENCC(hidden),VIIRS_SNPP_Brightness_Temp_BandI5_Night(hidden),MODIS_Terra_Brightness_Temp_Band31_Night(hidden)&t=2019-03-03-T00%3A00%3A00Z&z=3&t1=2019-03-02-T00%3A00%3A00Z&v=-133709.1701890404,1439143.1354370622,527026.4063599372,1819582.2916219032&ab=off&as=2017-09-01T00%3A00%3A00Z&ae=2019-02-01T00%3A00%3A00Z&av=8&al=true
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 03, 2019, 11:43:52 AM
There is this pronounced feature where ice is melting in the middle of the Laptev Sea.

Aha! If I now understand you correctly then that's the mobile "pack ice" being blown away from the static "fast ice" and the resulting gap refreezing?

P.S. Like wot Neven said!
Title: Re: The 2019 melting season
Post by: b_lumenkraft on March 03, 2019, 11:51:55 AM
Thank you Neven and Jim,

refreezing makes sense.

I thought is was melting because the thin ice there is like 10 degrees warmer than the surrounding ice. I got it all wrong. ^^
Title: Re: The 2019 melting season
Post by: Neven on March 03, 2019, 11:54:30 AM
Never attribute to temperatures that which is adequately explained by winds.  ;)
Title: Re: The 2019 Melting Season
Post by: Jim Hunt on March 03, 2019, 11:55:42 AM
JAXA has reported another drop, albeit a small one, so this one can stay open.  :)

It looks as though I squeezed past the ASIF proprietor's "melt" filter just in time?

There's a modest uptick in high res AMSR2 extent today.
Title: Re: The 2019 Melting Season
Post by: Neven on March 03, 2019, 12:00:13 PM
JAXA has reported another drop, albeit a small one, so this one can stay open.  :)

It looks as though I squeezed past the ASIF proprietor's "melt" filter just in time?

Yup, but you haven't made it to the sticky stage yet!  :D
Title: Re: The 2019 melting season
Post by: Paddy on March 03, 2019, 04:19:29 PM
DMI 80N seems to be making a slow start to warming up so far this year so far http://ocean.dmi.dk/arctic/meant80n.uk.php
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 03, 2019, 09:31:36 PM
Open water is now visible along the Beaufort Sea coast as well as in the Chukchi Sea, much of which is currently refreezing:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-03
Title: Re: The 2019 melting season
Post by: uniquorn on March 03, 2019, 10:28:10 PM
Worldview, terra modis, Beaufort, feb28-mar2.
Title: Re: The 2019 melting season
Post by: Neven on March 03, 2019, 10:31:11 PM
The question, as always: Will this open water refreeze again, once the winds turn? I think probably yes.
Title: Re: The 2019 melting season
Post by: jdallen on March 04, 2019, 06:14:05 AM
The question, as always: Will this open water refreeze again, once the winds turn? I think probably yes.
Then the next question, how thick will it be able to get?

At this stage, it definitely won't have a chance to get as tough as ice formed earlier in the season, much less MYI.
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on March 04, 2019, 06:37:08 AM
uniquorn what are those coordinates?  (Can't read them)
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 04, 2019, 09:01:15 AM
A less modest uptick today:
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 04, 2019, 09:04:30 AM
uniquorn what are those coordinates?

Here you go: https://go.nasa.gov/2IQLLgN
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 04, 2019, 09:30:11 AM
I don't suppose anybody in here happens to have Justin Trudeau's cell number do they?

https://twitter.com/jim_hunt/status/1102130759014535168

I linked to the ASIF long before I clicked the "2 others" button!
Title: Re: The 2019 melting season
Post by: Gray-Wolf on March 04, 2019, 03:06:34 PM
Since the flip in the Interdecadal Pacific Oscillation , back in 2014, I think I have seen the Pacific side of the basin taking an earlier pounding each year with the last 2 seeing little ice in the entrance to the basin from melt season 'get go'?

Could it be that the 0.5c increases in sst's the flip in the I.P.O. drives over its 30 year 'cycle' could now be giving melt season, over that side of the basin, and early shove?

We know that during a Nino the Kelvin waves work their way up the U.S. coast and into the basin via the Alaskan current so could a similar , if slower, train of ever warmer waters be working into that side of the basin ( and for the next 26 years?)

We have seen a portion of the Atlantic  entrance into the basin returning to a more 'normal' ocean profile since the turn of the century. Will the Pacific side , aided and abetted by the I.P.O. , now play catch up ?
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on March 05, 2019, 12:14:02 AM
uniquorn what are those coordinates?

Here you go: https://go.nasa.gov/2IQLLgN

Geez, I didn't realize that was so far zoomed out...that is terrifying...
Title: Re: The 2019 melting season
Post by: Rod on March 05, 2019, 07:05:00 AM
Juan and gerontocrat (my two favorite ice monitors) are telling us the extent is creeping back up. Maybe we will have another max? I won't guess, but I do know that the ice looks terrible right now in the Bering, Beaufort and Chukchi. 

Zack posted another clear image of the Bering today.  https://t.co/0UZgoTfsbY

Title: Re: The 2019 melting season
Post by: Jim Hunt on March 05, 2019, 09:28:54 AM
Juan and gerontocrat (my two favorite ice monitors) are telling us the extent is creeping back up.

"Snow White" is mortified!
Title: Re: The 2019 melting season
Post by: be cause on March 05, 2019, 09:44:43 AM
thanks Jim .. 2014 shows how a second peak could grow and grow ..
b.c.
Title: Re: The 2019 melting season
Post by: Neven on March 05, 2019, 11:49:55 AM
Yes, Jim, you're in a sticky situation now!

https://www.youtube.com/watch?v=DDZf3ZdqzbY

Quote
I don’t wanna fuss and fight
sick of the arguing and all the lies
To tell you the truth you got me thinking twice
thought I got it right

 ;)
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 06, 2019, 01:17:45 AM
Here's the weekly blended CS2/SMOS thickness update:
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 06, 2019, 09:12:04 AM
Arctic sea ice extent is currently still rebounding, although not in all the peripheral seas:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-06


More at the link.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 07, 2019, 09:21:27 AM
High resolution AMSR2 area and extent both declined today.

Long distance swells are already reaching the Bering Sea, with much more to come.
Title: Re: The 2019 melting season
Post by: sark on March 07, 2019, 10:41:34 AM
I've been squinting closely at the 500mb height charts, in forecast and hindsight.  Forecast indicates the polar cell seems to pull back into a compact configuration but immediately develop 5, 6, or 7 waves in the next week

Like the ridging from both the Atlantic & Pacific side that pinched off a section last week and yielded a good incursion of warm air across the Arctic Ocean, it gets very splitty again around 16-19 March.

Here's GEFS 500mb Forecast Hour 162 showing the tendancy to lobe up

And here's the GEFS 500mb Height Anomaly trend for days 12-16

Could be another sudden and strong incursion of warm air across the Arctic basin around the ides of March.
Title: Re: The 2019 melting season
Post by: Sterks on March 07, 2019, 03:14:13 PM
High resolution AMSR2 area and extent both declined today.

Long distance swells are already reaching the Bering Sea, with much more to come.
That's too big mechanical energy for the very young ice of those locations to resist.
Bye bye ice in the Pacific
Title: Re: The 2019 melting season
Post by: Gray-Wolf on March 07, 2019, 05:29:57 PM
I've been squinting closely at the 500mb height charts, in forecast and hindsight.  Forecast indicates the polar cell seems to pull back into a compact configuration but immediately develop 5, 6, or 7 waves in the next week

I read a tweet recently from one of the folk who model watch saying the 'final warming' of the Polar Night Jet looks set to be arriving around the 22nd of March so I wonder if this sudden 'flowering' into multiple lobes is a reaction to this 'final warming' in the polar Strat?

Once the PNJ is gone then I suspect we'll be seeing plenty of warm incursions into the basin as some poor sob's get hit with a final blow of polar air out of the basin?
Title: Re: The 2019 melting season
Post by: gerontocrat on March 07, 2019, 06:48:13 PM
Temperature anomalies look less and less like a melting Arctic Ocean over the next few days to me.
Big waves in the open Bering sea will have little effect in the Bering as the >70 k km2 of ice area left mostly attached to the coasts?
Really cold along the Atlantic Front.

Only surprise seems warmth arriving in the Okhotsk as cold arrives in the Bering.
Title: Re: The 2019 melting season
Post by: Sterks on March 07, 2019, 10:22:28 PM
Ice can increase in Bering but not because of temperature anomalies but because of ice import thru Bering Straight. In any case, wait until next week, as the wave energy will break all into pieces and mix ocean upper layers nicely.
Not everything is atmospheric temperature
Title: Re: The 2019 melting season
Post by: gerontocrat on March 08, 2019, 08:47:37 AM

Not everything is atmospheric temperature
I totally agree.

I am convinced by what I have read on the ASIF and elsewhere that it is ocean warmth and ocean currents and waves that are going to do for the Arctic Ocean ice.

But air temperatures can accelerate or delay that process. And for the next few days at least Arctic air temperatures look likely to allow new ice formation especially on the Atlantic Front, thereby  possibly causing a new ice extent maximum. (After Mar 7 increase JAXA extent only 101k below current max on 22 Feb).
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 08, 2019, 10:55:46 AM
The wave energy will break all into pieces and mix ocean upper layers nicely.
Not everything is atmospheric temperature

Especially for gerontocrat (& FooW!), my demonstration of the effects of wave energy on a yellow simulation of a small chunk of near shore sea ice:

http://youtu.be/ZYo9q_RRKTE
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 08, 2019, 11:09:47 AM
After Mar 7 increase JAXA extent only 101k below current max on 22 Feb.

However the high res area shows another significant decline:
Title: Re: The 2019 melting season
Post by: gerontocrat on March 08, 2019, 03:50:09 PM
After Mar 7 increase JAXA extent only 101k below current max on 22 Feb.

However the high res area shows another significant decline:
However,

Daily NSIDC Extent on 7 March up by 73k to 14.683 million KM2, and now only 52 k less than the current 2019 maximum of 14.735 million km2 on the 23 Feb.
Title: Re: The 2019 melting season
Post by: gerontocrat on March 08, 2019, 04:21:35 PM

However the high res area shows another significant decline:

Oren says something odd happening about UH or JAXA data for the Okhotsk. I think its UH data.

https://forum.arctic-sea-ice.net/index.php/topic,2533.msg191437.html#msg191437
Title: Re: The 2019 melting season
Post by: Supak on March 08, 2019, 06:34:00 PM
Can you guys help this noob out? Gerontocrat says "current 2019 maximum of 14.735 million km2 on the 23 Feb" for NSIDC. But I see the 23rd at 14.688, and the current max at 14.705 on the 24th.


https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Title: Re: The 2019 melting season
Post by: Neven on March 08, 2019, 08:02:18 PM
I think the answer is that GC is referring to daily numbers, while on the NSIDC website they use a 5-day trailing average.
Title: Re: The 2019 melting season
Post by: gerontocrat on March 08, 2019, 08:22:52 PM
I think the answer is that GC is referring to daily numbers, while on the NSIDC website they use a 5-day trailing average.
I use NSIDC 5 day trailing average for extent and area stuff by individual seas 'cos that's what NSIDC provide.

The 14.735 figure is from the NSIDC daily extent file, which does not go down to individual seas.
Title: Re: The 2019 melting season
Post by: Supak on March 08, 2019, 09:46:01 PM
Quote
The 14.735 figure is from the NSIDC daily extent file, which does not go down to individual seas.


So which one will be the "official" number they release when they announce the max?
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 09, 2019, 01:52:32 PM
Wipneus' Raspberry Pi has been a bit sluggish crunching the AMSR2 numbers today, but now reveals another modest decline in Arctic sea ice area:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-09
Title: Re: The 2019 melting season
Post by: gerontocrat on March 09, 2019, 02:06:28 PM
Quote
The 14.735 figure is from the NSIDC daily extent file, which does not go down to individual seas.

So which one will be the "official" number they release when they announce the max?
I am sure it is the daily extent number at three decimal places of a million km2- i.e. 10,000 km2.
Also note that in their user guide they talk about inherent uncertainty in the data.
 
Quote
Quote
Uncertainty in daily passive microwave estimates of Arctic-wide extent due to noise in the data and sensitivity to brightness temperatures is on the order of 30,000-50,000 sq km or 0.03-0.05 million sq km (personal communication, Walt Meier 05 Oct. 2016). Day-to-day differences on the order of 0.001 million sq km, as shown in these spreadsheets, are unimportant and are included only to serve as tie-breakers when ranking is done and to make it easier for users to do their own calculations without finding differences with our conclusions due to rounding errors.
[/size]
https://nsidc.org/sites/nsidc.org/files/files/data/noaa/g02135/Sea-Ice-Analysis-Spreadsheets-Overview.pdf
Title: Re: The 2019 melting season
Post by: gerontocrat on March 09, 2019, 02:40:02 PM
Daily NSIDC Extent up by 19k to 14.703 million KM2, and now only 32 k less than the current 2019 maximum of 14.735 million km2 on the 23 Feb..

UH AMSR2 extent going in opposite direction to JAXA and NSIDC for the last few days.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 09, 2019, 03:10:52 PM
UH AMSR2 extent going in opposite direction to JAXA and NSIDC for the last few days.

That's the "high resolution" for you?
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 09, 2019, 04:15:09 PM
"Snow White" is currently getting some grief (http://greatwhitecon.info/2019/03/arctic-basin-big-wave-surfing-contest-equipment-evaluation-3/#comment-270284) from a "skeptical" fellow. Hopefully this insight will persuade Michael of the error of his ways?
 
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 09, 2019, 09:02:17 PM
A modicum of (archived) approbation for yours truly from ex Prof. Judy:

http://archive.is/582eM#selection-1108.0-1114.2

I cannot argue with her assertion that:

Quote
This is the most important paper on this week’s list

https://www.atmos-chem-phys.net/19/2527/2019/
Title: Re: The 2019 melting season
Post by: bbr2314 on March 09, 2019, 11:33:20 PM
A comparison of HYCOM (apples to apples, otherwise not as useful) for this date this year vs. last year shows much thinner ice across most of the CAB, but especially peripheral to most of Eurasia. It looks like there is practically no thick ice adjacent to Siberia this year, a fairly dramatic drop from 2018.

On the other side, it looks like there is much thicker ice in Baffin and NE of Greenland, as well as a decent chunk NW of the Bering. However, all of these regions are likely to melt out anyways.

I suspect that the SWE situation in North America (now above 2018!) will seriously blunt momentum in Hudson Bay, Baffin, the CAA, and parts of the CAB through solstice. But on the other side of the planet, despite high SWE, Eurasian snow extent is now much below normal, and looking to drop substantially further as we head through the extended range. Temperatures have also been much above normal across large swathes of Siberia.

IF we do not see a surprise / substantial cold period take hold across Siberia in March and April, there could be a record early arrival of spring across much of the region, and the state of the sea ice in the ESS / Chukchi is so abysmal that this could translate into a major problem come May and June. It also looks like the FYI is thinner in the Beaufort vs. 2018, which should (IMO) result in the same "poofage" we saw occur in August of 2018 happen earlier in 2019 (especially when the heat is acting in concert with a snow-free blast furnace developing over Eurasia).

(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn/nowcast/ictn2019030812_2019030900_930_arcticictn.001.gif)

(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn/nowcast/ictn2018030812_2018030900_930_arcticictn.001.gif)
Title: Re: The 2019 melting season
Post by: bbr2314 on March 10, 2019, 03:59:24 AM
Also worth noting -- how do we look compared to this point in 2012?

The answer is, DIFFERENT! But mostly warmer in the crucial regions, and by A LOT in Beaufort.

This is for 3/4-3/7 which is admittedly a narrow look, but in the seven years since 2012, parts of North America are now running 20C colder than at this point that year. There is also a pocket of severe cold in the Barentz and northern Kara.

On the flip side, parts of Baffin / the Labrador Sea are up to +20C vs seven years ago! The most severe warming also extends across much of the Bering and Beaufort shorelines. Much of Siberia is running +10C or higher than at this point that year, and much of Europe is also much above normal.

Finally: I do not have snow depth maps for many years, but you can compare the EURO with 2018 for both depth and SWE. Given the departure map vs 2012 I'd assume we'd also be at a big deficit versus that year, but the change vs. 2018 is very steep across much of northern Siberia.

https://weather.us/model-charts/euro/northern-asia/snow-water-equivalent/20190310-0300z.html

2019^

https://weather.us/model-charts/euro/2018030912/northern-asia/snow-depth-in/20180319-1200z.html

2018^

Western Siberia has seen substantial year over year gains and so have some areas with significant elevation, but overall, there is a massive dearth of SWE and depth in areas south of the ESS and Chukchi. So far, 2019's trends would seem to indicate these areas are not in for major snows in March or April (as they would be in normal years). If that is indeed the case, we are going to see a wide area of Eurasia more than counteract the +anomaly in North America, and the ensuing albedo feedbacks are likely to result in extraordinarily early melt-out of the ESS in particular, and likely the Chukchi and Laptev as well.

It will be curious to see if, how, and when the albedo situation in Eurasia truly begins to spiral, but it may already be occurring. We are over -1SD below recent norms.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/eu_sce.png)

The combination of a lack of SWE and a lack of any substantive shore ice means that when the boundary stops refreezing, the Eurasian shorelines are going to rip open, the ice is going to retreat quickly, and we are likely to accumulate significant springtime insolation in areas where that has never happened in the satellite record.
Title: Re: The 2019 melting season
Post by: Aluminium on March 10, 2019, 08:21:02 AM
March 2-9.
Title: Re: The 2019 melting season
Post by: oren on March 10, 2019, 10:13:58 AM
March 2-9.
The Chukchi has grown back.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 10, 2019, 10:51:24 AM
The Chukchi has grown back.

Not unexpectedly, but these are nervous times for those of us who called a February maximum!

More at: http://greatwhitecon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-10
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 10, 2019, 10:55:32 AM
A comparison of HYCOM (apples to apples, otherwise not as useful)

Note that there are "measured" as well as "modelled" Arctic sea ice thickness maps available, although not necessarily with a long history:

http://GreatWhiteCon.info/2019/01/facts-about-the-arctic-in-january-2019/#comment-268997
Title: Re: The 2019 melting season
Post by: gerontocrat on March 10, 2019, 04:37:06 PM
The Chukchi has grown back.

Not unexpectedly, but these are nervous times for those of us who called a February maximum!

More at: http://greatwhitecon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-10

I no longer have to wonder if the cold on the Atlantic Front will be sufficient to allow significant ice gain to make a new NSIDC maximum extentDaily NSIDC Extent up by 38k to 14.740 million KM2, 5k greater than what was the current 2019 maximum of 14.735 million km2 on the 23 Feb..

Extent is still likely to dither up and down for some time..

JAXA ARCTIC EXTENT : 14,150,474 km2(March 9, 2019) The Perils of Projections.

- Extent now just 44k less than current maximum on 22 Feb,
- Remaining ice gain in 5 out of the previous 10 years still gives a resulting maximum of MORE than 14.195 million km2 .
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 10, 2019, 11:58:29 PM
Daily NSIDC Extent up by 38k to 14.740 million KM2, 5k greater than what was the current 2019 maximum of 14.735 million km2 on the 23 Feb.

However I reserve the right not to eat the crow pie (https://forum.arctic-sea-ice.net/index.php/topic,1837.msg104183.html#msg104183) you have prepared until the UH AMSR2 and Charctic numbers have followed suit!
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 11, 2019, 09:24:59 AM
JAXA/VISHOP seems to be down this morning (UTC)?

https://ads.nipr.ac.jp/vishop/

I get redirected to their Twitter feed (https://twitter.com/ADS_NIPR), which doesn't seem to include any helpful explanation of the (hopefully brief) hiatus.

The high res UH AMSR2 concentration data is already available for March 10th, so that's not the issue.

Title: Re: The 2019 melting season
Post by: Jim Hunt on March 11, 2019, 12:23:14 PM
JAXA/VISHOP seems to be down this morning (UTC)?

The high res UH AMSR2 concentration data is already available for March 10th, so that's not the issue.

Wipneus' RasPi has crunched those numbers:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-11

"Snow White" can put off tucking into "her" crow pie for one more day at least.
Title: Re: The 2019 melting season
Post by: gerontocrat on March 11, 2019, 03:07:36 PM
Unusually low temps in the stratosphere at the North Pole persist.
But what is the significance thereof ?
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 11, 2019, 04:08:35 PM
Jaxa is still down this afternoon (UTC), but here's the latest from the NSIDC:
Title: Re: The 2019 melting season
Post by: gerontocrat on March 11, 2019, 05:25:24 PM
Jaxa is still down this afternoon (UTC), but here's the latest from the NSIDC:
Does one use NSIDC daily extent or 5 day trailing average extent?
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 11, 2019, 05:35:25 PM
Does one use NSIDC daily extent or 5 day trailing average extent?

The NSIDC use the averaged value in their official announcements. See for example:

http://GreatWhiteCon.info/2018/03/the-2018-maximum-arctic-sea-ice-extent/
Title: Re: The 2019 melting season
Post by: gerontocrat on March 11, 2019, 05:42:53 PM
Does one use NSIDC daily extent or 5 day trailing average extent?

The NSIDC use the averaged value in their official announcements. See for example:

http://GreatWhiteCon.info/2018/03/the-2018-maximum-arctic-sea-ice-extent/

Then 9k to go
date    NSIDC Daily extent   NSIDC 5 day extent
22/02/19   14.698   14.646
23/02/19   14.735   14.688
24/02/19   14.682   14.705
25/02/19   14.587   14.686
26/02/19   14.548   14.65
27/02/19   14.585   14.627
28/02/19   14.561   14.592
01/03/19   14.533   14.563
02/03/19   14.556   14.556
03/03/19   14.617   14.57
04/03/19   14.611   14.576
05/03/19   14.612   14.586
06/03/19   14.61   14.601
07/03/19   14.684   14.627
08/03/19   14.702   14.644
09/03/19   14.743   14.67
10/03/19   14.742   14.696
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 11, 2019, 05:50:05 PM
Unusually low temps in the stratosphere at the North Pole persist.
But what is the significance thereof ?

Perhaps this is relevant?

https://twitter.com/mikarantane/status/1104807136163450887

Quote
Not often you see the center of stratospheric polar vortex located ≥ 88°N at all levels from 150 hPa to 1 hPa (in 3-day forecast). Exceptionally strong and symmetric vortex for the time of the year!
Title: Re: The 2019 melting season
Post by: Iain on March 11, 2019, 09:11:32 PM
Not a serious objection, but shouldn't the extent uptick be discussed in the freezing thread rather than the melting thread?

More freez-ing happening than melt-ing (extent wise) is the reason for the uptick.


Title: Re: The 2019 melting season
Post by: Tealight on March 12, 2019, 02:37:40 AM
A short off topic announcement & question. (It will help you following sea ice melt in the future)

I'm trying to get off googlesites to get more presentation freedom and created a webpage with github pages and a proper address saluting to the glorios pacific atoll of Tokelau.  :D

https://cryospherecomputing.tk/

Currently it's just a generic template with links to the images on googledrive thrown into. None of the buttons should do anything. Does anybody have problems accessing the website or seeing any of the images?

Attached is an image of all Tokelau islands (stuck next to each other) and how the website should look like on a 1080p monitor.
Title: Re: The 2019 melting season
Post by: miki on March 12, 2019, 04:23:37 AM
https://cryospherecomputing.tk/
Does anybody have problems accessing the website or seeing any of the images?

No problem here. I see the page ok on my macbook with Chrome.
Title: Re: The 2019 melting season
Post by: Sebastian Jones on March 12, 2019, 07:08:45 AM
It is wonderful, and I'm bookmarking it!
Title: Re: The 2019 melting season
Post by: oren on March 12, 2019, 07:18:21 AM
It is wonderful, and I'm bookmarking it!
Same here.
Works on Windows 10 for with both Chrome and IE.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 12, 2019, 08:13:23 AM
Does anybody have problems accessing the website or seeing any of the images?

It works OK for me using Firefox on Scientific Linux.

I'll try a few other combinations in due course.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 12, 2019, 09:42:34 AM
It's crow pie time by a whisker, if that's not an awful mix of metaphors. I doubt that the Charctic numbers will save "Snow White's" bacon!
Title: Re: The 2019 melting season
Post by: Tealight on March 12, 2019, 06:36:30 PM
Thanks to all who tested the website. In the future just pm me to keep the thread clean.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 13, 2019, 10:08:32 AM
Extent continues ever upwards:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-13

However excluding the ultimately irrelevant periphery....
Title: Re: The 2019 melting season
Post by: gerontocrat on March 13, 2019, 02:29:31 PM
NSIDC Extent (5 day trailing average) will increase for at least the next 2 or 3 days simply because it is a trailing average. Same applies to ice area. After that it is in the hands of the ice Goddesses.
___________________________________________________________________________
Khione is the Greek goddess of snow, daughter of Boreas, god of the North Wind and Winter, and sister of Zethes and Calais. She is depicted as a goddess in the series, although in some myths she is visualized as a snow nymph.

In Norse mythology  Skaði was the beautiful and cold (no pun intended ) jotunn , a female jotunn (giant) and the  goddess associated with the skiing and winter .
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 14, 2019, 08:53:57 AM
Extent continues ever upwards

But not any more:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-14
Title: Re: The 2019 melting season
Post by: be cause on March 14, 2019, 11:04:11 AM
minor blip .. b.c.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 15, 2019, 09:40:55 AM
Another modest extent decline today:
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 15, 2019, 10:12:55 PM
Another modest extent decline today:

Confirmed by the recently returned JAXA:

Title: Re: The 2019 melting season
Post by: oren on March 16, 2019, 10:02:40 AM
This thread should be made sticky instead of the freezing season thread.
And that is my final call.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 16, 2019, 01:39:26 PM
Arctic sea ice extent continues to decline:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-16

Meanwhile a look at freezing degree days based on the DMI's dubiously weighted data for north of 80 degrees reveals the story of the freezing season. A historically warm start, but now back in amongst the pack of the 2010s:
Title: Re: The 2019 melting season
Post by: El Cid on March 16, 2019, 02:12:19 PM
This thread should be made sticky instead of the freezing season thread.
And that is my final call.

Yes, it is probably time.

Nonetheless, the change from freezing season to melting season is always gradual and is a sort of "sideways season" or "topping out season". This period always takes many weeks and arguing about whether we have already hit the top or not is quite pointless in my view. Extent is topping out but it is a drawn out process - drawing lines in the sand is an exercise in futility...
Title: Re: The 2019 melting season
Post by: Neven on March 16, 2019, 03:21:07 PM
This thread should be made sticky instead of the freezing season thread.
And that is my final call.

One more JAXA SIE drop tomorrow, and I'll make it happen.  :)
Title: Re: The 2019 melting season
Post by: Thomas Barlow on March 16, 2019, 08:45:58 PM
Does anyone have a graph that compares the overall average Arctic winter temperatures year to year?
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on March 16, 2019, 09:14:50 PM
Does anyone have a graph that compares the overall average Arctic winter temperatures year to year?

http://ocean.dmi.dk/arctic/meant80n_anomaly.uk.php
Title: Re: The 2019 melting season
Post by: El Cid on March 16, 2019, 09:33:06 PM
Does anyone have a graph that compares the overall average Arctic winter temperatures year to year?

I just happen to have one, cci/giss data, 70-90N, the first one is dec-jan -feb, the second is oct to feb
Title: Re: The 2019 melting season
Post by: HapHazard on March 17, 2019, 02:09:16 AM
This thread should be made sticky instead of the freezing season thread.
And that is my final call.

Yep.

And honestly, I really dislike having 2 threads open at once.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 17, 2019, 05:40:36 AM
The ice front off Newfoundland has made remarkable progress south. It is hardly consistent but I believe these tendrils may be the furthest south in the satellite record by a wide margin. I wonder if we can beat this in 2019-20 as SSTs are VERY low and the "cool pool" seems to have decided to rendezvous with North America this year instead of remaining out in the NATL.

(https://ice-glaces.ec.gc.ca/prods/WIS27ECT/20190316180000_WIS27ECT_0010498948.gif)

This will all melt soon, of course. 2019's #s are currently inflated by absurd southerly ice extent in the St. Lawrence and Okhotsk.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 17, 2019, 09:50:11 AM
One more JAXA SIE drop tomorrow, and I'll make it happen.  :)

Here you go Neven:
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 17, 2019, 11:37:43 AM
This will all melt soon, of course. 2019's #s are currently inflated by absurd southerly ice extent in the St. Lawrence and Okhotsk.

High this year, but by no means unprecedented:
Title: Re: The 2019 melting season
Post by: El Cid on March 17, 2019, 11:52:56 AM
It seems to me that as the Bering and the Atlantic freezes later and later this allows us to have frequent warm intrusions (even up to the North Pole - as we remember from the past years). These intrusions "push" the cold air out of the Arctic and this leads to more ice in the Okhotsk and colder/icy weather in Quebec. So it seems that what we observe in the Okhotsk/St.Lawrence area is the obvious (in hindsight of course :) consequence of Arctic warming.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 17, 2019, 12:03:27 PM
This will all melt soon, of course. 2019's #s are currently inflated by absurd southerly ice extent in the St. Lawrence and Okhotsk.

High this year, but by no means unprecedented:
I didn't mean the entirety of these areas, just the lone Newfoundland tendril in its southerly extent down to below 45N, which is pretty crazy! Although it is very limited in scope, it is still wayyyyy south of normal (and will likely melt out very soon).
Title: Re: The 2019 melting season
Post by: gerontocrat on March 17, 2019, 12:36:24 PM
This thread should be made sticky instead of the freezing season thread.
And that is my final call.

One more JAXA SIE drop tomorrow, and I'll make it happen.  :)
And it happened
Title: Re: The 2019 melting season
Post by: uniquorn on March 17, 2019, 12:51:33 PM
http://polarportal.dk/en/sea-ice-and-icebergs/  ice surface temperature for the last freezing season (for reference)
Title: Re: The 2019 melting season
Post by: Gray-Wolf on March 17, 2019, 02:21:43 PM
It seems to me that as the Bering and the Atlantic freezes later and later this allows us to have frequent warm intrusions (even up to the North Pole - as we remember from the past years). These intrusions "push" the cold air out of the Arctic and this leads to more ice in the Okhotsk and colder/icy weather in Quebec. So it seems that what we observe in the Okhotsk/St.Lawrence area is the obvious (in hindsight of course :) consequence of Arctic warming.

I think you make a valid observation El Cid!

On top of what you say I'll add my own obs. This past winter I was more than surprised to see the Polar night Jet set up in 'orderly fashion' ( compared to ther last decade or so with its 'dumbbell shapes and splits?) and keep a steady vortex even with the late Dec/early Jan split/warming?

It is still powering away right now as we approach its 'final warming'.

In past years the wobbly PNJ picked out where our 'polar plunges' were occuring? This time it appears the full thickness of the atmosphere pushed these plunges out regardless of the PNJ's 'corralling' ?

Like an erupting zit it burst through the confides of the PNJ.

I started the refreeze head scratching at how well behaved the PNJ was being. I end refreeze thinking that the PNJ's 'influence' is now overpowered by the atmosphere's own volatility and no matter how hard it tries it can no longer be relied upon to keep the cold inside it and the warm outside it?
Title: Re: The 2019 melting season
Post by: Thomas Barlow on March 17, 2019, 03:28:50 PM
ReverendMilkbone, El Cid.

Thanks. these are useful.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 17, 2019, 03:31:29 PM
A couple of images from "Snow White's" new Arctic Webcams (http://greatwhitecon.info/resources/arctic-webcams/) page.

There's not a lot of melting required on the west coast of Svalbard!



Title: Re: The 2019 melting season
Post by: uniquorn on March 17, 2019, 06:17:03 PM
DMI (sep24-mar15) and PIOMAS (sep24-feb28) thickness models for last freezing season for reference.
Both models suggesting that the area north of FJL/Svalbard is weak for some distance. It does look a bit 'crazy paving' in viirs, brightness temperature(band15)night  https://go.nasa.gov/2JlnwY8

added cryosat 28day, feb13-mar13 for comparison.
Title: Re: The 2019 melting season
Post by: jdallen on March 17, 2019, 07:44:39 PM
This will all melt soon, of course. 2019's #s are currently inflated by absurd southerly ice extent in the St. Lawrence and Okhotsk.

High this year, but by no means unprecedented:
And if anything, a trend up over the last few years.

I think the Okhotsk, St. Lawrence, Labrador and Baffin (and to a lesser degree, Greenland) regions will all be beneficiaries of increasing instability of winter polar circulation.

Over all, while they may create the appearance of modestly stable winter maximum extents, they in fact represent the export of both ice and cold air out of the regions that most need to retain them.

Volatility in the system is increasing rapidly.
Title: Re: The 2019 melting season
Post by: uniquorn on March 17, 2019, 10:24:15 PM
The ice front off Newfoundland has made remarkable progress south. It is hardly consistent but I believe these tendrils may be the furthest south in the satellite record by a wide margin.
Pretty close to 2014 and 2015 on amsr2 so far. I'll let you confirm with worldview(geographic maybe?)  :)
amsr2, newfoundland, mar2013-2019
Title: Re: The 2019 melting season
Post by: bbr2314 on March 18, 2019, 02:22:50 AM
The ice front off Newfoundland has made remarkable progress south. It is hardly consistent but I believe these tendrils may be the furthest south in the satellite record by a wide margin.
Pretty close to 2014 and 2015 on amsr2 so far. I'll let you confirm with worldview(geographic maybe?)  :)
amsr2, newfoundland, mar2013-2019
I am talking about the lone tendril that has drifted down to below 45N. The overall extent in the region is similar to previous years but there is now a southerly tendril that is well into the NATL shipping lanes.

The Canuck ice maps are more illustrative but you can see this on EOSDIS as well. It looks like it is breaking up at this point which is hardly surprising considering how far south it is.

(https://ice-glaces.ec.gc.ca/prods/WIS27ECT/20190317180000_WIS27ECT_0010500385.gif)
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 18, 2019, 09:05:12 AM
Arctic sea ice area is finally following extent’s recent decline in no uncertain terms:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-17

Barring exceedingly unforeseen circumstances after this year's "double top" that leaves the 2019 Arctic sea ice maximum extent numbers as follows:

UH/Wipneus AMSR2 - 13.89 million square kilometres on March 12th
JAXA/VISHOP AMSR2 - 14.27 million square kilometres on March 12th
NSIDC 5 day SSMIS - 14.78 million square kilometres on March 13th
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 18, 2019, 10:34:54 AM
The Canuck ice maps are more illustrative

Like this one you mean?

Title: Re: The 2019 melting season
Post by: bbr2314 on March 18, 2019, 12:38:31 PM
The Canuck ice maps are more illustrative

Like this one you mean?
Exactly, the ice is two degrees south of 2015's phenomenal extent.  ;)
Title: Re: The 2019 melting season
Post by: uniquorn on March 18, 2019, 12:43:00 PM
Thank you both. Agreed, the tendrils are further south, maybe 200km. SST must be cooler or surface salinity fresher there. Perhaps as a result of all the MYI in the CAA last season?
edit: Concentration is a lot lower this year though.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 18, 2019, 01:18:13 PM
Exactly, the ice is two degrees south of 2015's phenomenal extent.  ;)

It was much more substantial in 2015 though!
Title: Re: The 2019 melting season
Post by: bbr2314 on March 18, 2019, 01:31:57 PM
Exactly, the ice is two degrees south of 2015's phenomenal extent.  ;)

It was much more substantial in 2015 though!
I didn't say it wasn't? My point wasn't on overall extent it was the ridiculous tendril that has made it to 44N. You are picking an absurd fight here for no reason.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 18, 2019, 01:41:05 PM
Thank you both. Agreed, the tendrils are further south, maybe 200km. SST must be cooler or surface salinity fresher there. Perhaps as a result of all the MYI in the CAA last season?
edit: Concentration is a lot lower this year though.
I think there may have been some misbehavior from the Beaufort Gyre last summer which may have contributed to this. The SST gradient south of Newfoundland and Nova Scotia is substantially further S this year than in 2015 (and any other recent year).

(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsst/nowcast/sst2019031612_2019031700_930_arcticsst.001.gif)

(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsst/nowcast/2015/sst2015031612_2015031700_563_arcticsst.001.gif)

At the same time, the area of mixing east of Newfoundland actually appears to be N of 2015. It looks like the SST changes also correspond to a substantial drop in salinity in the same region. While there have been consistent drops on the Scotian Shelf and the Grand Banks, it appears the largest change in 2019 has been on George's Bank, which has seen salinity drop 10% year over year (it has been fairly consistent until this year).

(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss/nowcast/sss2019031612_2019031700_930_arcticsss.001.gif)

(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss/nowcast/2015/sss2015031612_2015031700_563_arcticsss.001.gif)

Besides the Beaufort Gyre's possible involvement it appears as though much of the NATL east of this gradient is substantially saltier than four years ago. Perhaps as the volume of warm water heading east / northeast increases, more of the freshwater input from Baffin / up north is kept closer to the continental shelf and the NE seaboard of North America? I don't know exactly what is going on but this is a pretty big change for a relatively low-latitude area that is bound to have significant impacts on sensible weather for both Eastern North America and Western Europe.

I would think the changes since 2015 (and year over year) may portend an impending summer that is even warmer than 2018 was over much of Europe.
Title: Re: The 2019 melting season
Post by: uniquorn on March 18, 2019, 01:46:16 PM
I didn't want to be alarmist and mention the Beaufort Gyre  ;)

bbr your image links are broken for me.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 18, 2019, 01:49:54 PM
I didn't want to be alarmist and mention the Beaufort Gyre  ;)

bbr your image links are broken for me.
Alas! Go here and compare dates. Feel free to upload the screengrabs. :)

https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

Also found the ATL sector:

https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/glfstr.html

Attaching actual files for 2019, 2019, and 2015. There has definitely been a push this year.
Title: Re: The 2019 melting season
Post by: uniquorn on March 18, 2019, 02:20:56 PM
Antivirus didn't like the certificate.
Interesting. I don't look that far south very often.
edit:For those with limited 2d spatial recognition, myself included, here is hycom gulfstream sst 2015-2019 mar17(or closest date). Will compare with mercator later.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 18, 2019, 03:00:48 PM
You are picking an absurd fight here for no reason.

I'm not picking any sort of a fight.

I am however implying that the 2019 melting season is likely to progress more rapidly in this vicinity than in 2015.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 18, 2019, 03:02:07 PM
You are picking an absurd fight here for no reason.

I'm not picking any sort of a fight.

I am however implying that the 2019 melting season is likely to progress more rapidly in this vicinity than in 2015.
OK :)

And I agree!
Title: Re: The 2019 melting season
Post by: Shared Humanity on March 18, 2019, 05:29:53 PM
While some ice may have strayed further south into the Atlantic than is typical, the ice in the Baffin Newfoundland Bay region is historically low, as compared to recent years.
Title: Re: The 2019 melting season
Post by: FishOutofWater on March 18, 2019, 05:41:33 PM
Both the Labrador current and the Gulf Stream are amped up this year. The lowest sea surface heights are in the Labrador sea, and SSH levels are higher pretty much everywhere else in the N Atlantic than they were just a few years back.

The images below tell part of the SSH story, but day to day comparisons of SSH may be affected by air pressure differences and differences in winds that may push SSH levels up along shorelines. However, it appears that the Beaufort gyre has lost fresh water volume and that deep convection is pretty strong in the Labrador sea this winter. That's consistent with intensification of the Gulf Stream and the Labrador current and with this winter's weather.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20190317%2Farc%2FA%2Fpsy4qv3r1_20190317_arc_sea_surface_height_0m.png&hash=8e7e918446ec3e1936fe24c03681109e)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20180317%2Farc%2FA%2Fpsy4qv3r1_20180317_arc_sea_surface_height_0m.png&hash=31ce2fa26d914d5d10ef3fd8a2e41554)
Title: Re: The 2019 melting season
Post by: FishOutofWater on March 18, 2019, 06:21:37 PM
Wind anomalies have been impressive for the past 30 days. The southerly flow from the north Pacific through the Bering strait into the Arctic seas has been intense.  Stronger than normal northwest winds have driven ice down the western side of Baffin bay and the Labrador sea. These crazy winds have even cause a large build up of heat in the western Pacific offshore of Japan.

Stronger than normal NW winds in the Labrador sea this late winter is a continuation of a pattern we saw late last winter and spring when there was a strong atmospheric vortex around Greenland. This pattern causes larger than normal amounts of fresh water flow out of the CAA into the Labrador sea.
Title: Re: The 2019 melting season
Post by: Shared Humanity on March 18, 2019, 06:31:35 PM
Both the Labrador current and the Gulf Stream are amped up this year. The lowest sea surface heights are in the Labrador sea, and SSH levels are higher pretty much everywhere else in the N Atlantic than they were just a few years back.

The images below tell part of the SSH story, but day to day comparisons of SSH may be affected by air pressure differences and differences in winds that may push SSH levels up along shorelines. However, it appears that the Beaufort gyre has lost fresh water volume and that deep convection is pretty strong in the Labrador sea this winter. That's consistent with intensification of the Gulf Stream and the Labrador current and with this winter's weather.

Many here talk about the ongoing Atlantification of the Barents. Looking at those images, it suggests that the long term effects of global warming could be the Atlantification of the Arctic Ocean.
Title: Re: The 2019 melting season
Post by: uniquorn on March 19, 2019, 12:44:48 AM
<snippage>
Stronger than normal NW winds in the Labrador sea this late winter is a continuation of a pattern we saw late last winter and spring when there was a strong atmospheric vortex around Greenland. This pattern causes larger than normal amounts of fresh water flow out of the CAA into the Labrador sea.
hmmm. It must be significantly larger than normal to let thin ice travel 200km further south.

Or perhaps just a one off fluke?
Title: Re: The 2019 melting season
Post by: Aluminium on March 20, 2019, 06:52:29 AM
March 12-19.

Equinox.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 20, 2019, 09:34:31 AM
Snowcover is now melting very very quickly across NW Canada. Airmasses may soon have a completely snow-free path into the Beaufort, even if Quebec remains intact. I think this may spell a very early melt-out of the Beaufort, which would starkly contrast what happened last year.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)

It is also worth noting that Eurasia is also seeing major deficits in any locations that aren't immediately adjacent to the Arctic Ocean, similar to Canada but more widespread. We may be in for a very early start to the melt season across Beaufort, ESS, and Chukchi in particular (no point mentioning Bering because it is already on the way to ice-free).

If the 00z models are correct, most of NW Canada will be entirely snow-free within the week, which would be absurdly early relative to normal.
Title: Re: The 2019 melting season
Post by: bbr2314 on March 20, 2019, 10:19:09 AM
These maps are going to look much worse when data becomes available for the 18th-19th (and beyond). This is the discrepancy vs. 2012 from the 15th-17th. A limited range, but it gets the point across on how this year is now misbehaving very badly in the Arctic, especially in the regions mentioned in my prior post. That is a +20C differential over spots!

Title: Re: The 2019 melting season
Post by: uniquorn on March 20, 2019, 01:15:02 PM
Update on ascat, jan21-mar19.
Polarview, north of SZ, mar19. The older ice clearly discernible form the younger.

973hPa over the persistent low concentration area north of Svalbard forecast by GFS for the day after tomorrow. http://tinyurl.com/y3p7bx7s
ECMWF forecasting 980hPa in the same area with 4m waves in the Fram Strait, 5m in the Barentsz http://tinyurl.com/yxs3gmue
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 20, 2019, 02:46:18 PM
ECMWF forecasting 980hPa in the same area with 4m waves in the Fram Strait, 5m in the Barentsz

I'm currently away from base, so I shall be forced to try and install Panoply on my little laptop!

https://forum.arctic-sea-ice.net/index.php/topic,1871.msg101738.html#msg101738
Title: Re: The 2019 melting season
Post by: oren on March 20, 2019, 03:05:23 PM
Update on ascat, jan21-mar19.
Polarview, north of SZ, mar19. The older ice clearly discernible form the younger.

973hPa over the persistent low concentration area north of Svalbard forecast by GFS for the day after tomorrow. http://tinyurl.com/y3p7bx7s
ECMWF forecasting 980hPa in the same area with 4m waves in the Fram Strait, 5m in the Barentsz http://tinyurl.com/yxs3gmue
Many thanks for these ASCAT updates.
It seems export of old ice picked up in March both through the Fram and through the gap north of Svalbard.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 20, 2019, 03:06:33 PM
After flatlining for a while Arctic sea ice area has fallen off the proverbial cliff over the last few days:

http://GreatWhiteCon.info/2019/03/the-2019-maximum-arctic-sea-ice-extent/#Mar-19
Title: Re: The 2019 melting season
Post by: johnm33 on March 20, 2019, 11:22:33 PM
uniquorns animation was so different to the circulation patterns as I rememered them, so I checked https://forum.arctic-sea-ice.net/index.php/topic,2278.msg146696.html#msg146696 has an A-Team ascat animation to compare. Though as sidd has it, read the whole thing, https://forum.arctic-sea-ice.net/index.php/topic,2278.0.html
Title: Re: The 2019 melting season
Post by: Ktb on March 21, 2019, 12:13:47 AM
Slater projection is up and running for those interested.

http://cires1.colorado.edu/~aslater/SEAICE/
Title: Re: The 2019 melting season
Post by: Thomas Barlow on March 21, 2019, 01:47:27 AM
After flatlining for a while Arctic sea ice area has fallen off the proverbial cliff over the last few days:
Ha ha ha.
You are not kidding.
This can't be right !?

http://tinyurl.com/y3qxmuwx
Title: Re: The 2019 melting season
Post by: bbr2314 on March 21, 2019, 09:44:52 AM
Oh dear. Another major loss. 00z models continue to show strong +500MB blocking over Bering and Beaufort reaching into ESS / Chukchi as we head toward medium and LR. Sping has spung.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)
Title: Re: The 2019 melting season
Post by: bbr2314 on March 21, 2019, 11:35:26 AM
 :o

(https://www.tropicaltidbits.com/analysis/models/gfs/2019032106/gfs_T2ma_namer_17.png)

It is absurdly early in the season for sustained heatwaves / +0C temps into the Arctic, but here we are...

(https://www.tropicaltidbits.com/analysis/models/gfs/2019032106/gfs_T2ma_namer_25.png)

(https://www.tropicaltidbits.com/analysis/models/gfs/2019032106/gfs_T2ma_namer_33.png)

The pre-conditioning and melt ponding from current model output over the next two weeks leads me to believe we are not in for a meek start, middle, or finish to the melt season.

We also have data in from the 18th. Attaching the departures vs. normal, and the departure vs. 2012. That is indeed an area of +30C temps (vs 2012) appearing over a wide swath of NW North America. 30C is 54F. That is nothing short of catastrophic re: impending melt.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on March 21, 2019, 01:37:14 PM
After flatlining for a while Arctic sea ice area has fallen off the proverbial cliff over the last few days:
Ha ha ha.
You are not kidding.
This can't be right !?

http://tinyurl.com/y3qxmuwx

Ok, it's been fixed now. Phew!
Title: Re: The 2019 melting season
Post by: uniquorn on March 22, 2019, 01:14:35 PM
This is almost exactly what we don't want. 972hPa over the Barentsz and warm winds from the Pacific side. An extra push for all the older ice towards the Atlantic.
Nullschool gfs temp forecast mar22 for mar24
Title: Re: The 2019 melting season
Post by: Tor Bejnar on March 22, 2019, 02:31:49 PM
The Lincoln Sea Polynya, which was quite stable for over a month, just collapsed, so there will be renewed export through Nares Strait (unless an arch forms in it, but I rather doubt it will this season - a repeat of 2006-7?).  See images in Nares Strait thread (https://forum.arctic-sea-ice.net/index.php/topic,176.msg192495.html#msg192495) (above and below linked post).
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on March 22, 2019, 08:43:50 PM
This is almost exactly what we don't want. 972hPa over the Barentsz and warm winds from the Pacific side. An extra push for all the older ice towards the Atlantic.
Nullschool gfs temp forecast mar22 for mar24

The video from your previous post showed this really well, (Post #145 on this thread, can't figure out how to link) Looked like a bakers pastry bag squeezing the old ice down the coast of Greenland.
Title: Re: The 2019 melting season
Post by: Eco-Author on March 23, 2019, 03:19:07 AM
Perhaps due to the El Nino and a warmer/The warmest Temps (record Jan.) down low (likely creating a stronger jet during the deep winter) the Jetstream was just too strong to let the warmth up to the pole compared to the last three-four years?  Will there be a later surge before summer as--perhaps--the temp difference balances out?!!
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 23, 2019, 10:07:50 AM
There's been something of a "rebound" in the Bering Sea:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#Mar-23
Title: Re: The 2019 melting season
Post by: sark on March 23, 2019, 11:33:48 AM
I don't even know where to post this.  According to GFS at 8 days, Alaska is going to get a taste of southern Texas weather around April 1.

looks to me like the polar cell gets distorted into a figure 8 shape, both cores trying to fly counterclockwise.  then the arctic gets a blast of warm air.  while we're dealing with wild weather, the polar cell consolidates into a circular shape.  the whole thing rotates counterclockwise for about a week and then begins to lobe as the perimeter lengthens.  then the cold rattles around all that loose perimeter until the polar cell splits, the arctic gets a blast of warm air, and then the whole thing twangs back together again.  the cycle repeats but now it's 4 - 5 times per year.

Posting GFS and wind vector anomalies I've been looking at
Title: Re: The 2019 melting season
Post by: uniquorn on March 23, 2019, 01:10:12 PM
amsr2, bering, jan1-mar22. Some similarities to last year. Wind driven flash melt/refreeze.
Title: Re: The 2019 melting season
Post by: jdallen on March 24, 2019, 03:50:54 AM
There's been something of a "rebound" in the Bering Sea:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#Mar-23
Yeah - seriously contributed to recent extent increases - but no doubt is barely thicker than slash.

Another week and a half and I'll be surprised if it doesn't vanish along with a bunch of similar extent that formed in the Chukchi.
Title: Re: The 2019 melting season
Post by: gerontocrat on March 24, 2019, 11:37:08 AM
There's been something of a "rebound" in the Bering Sea:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#Mar-23
Yeah - seriously contributed to recent extent increases - but no doubt is barely thicker than slash.

Another week and a half and I'll be surprised if it doesn't vanish along with a bunch of similar extent that formed in the Chukchi.
Temp anomalies may assist in the melt.
Title: Re: The 2019 melting season
Post by: Niall Dollard on March 24, 2019, 08:22:43 PM
The main pack has been pulling away from the Alaskan coast west of Point Barrow and pushing back again as winds change.  Worldview image from yesterday shows a reasonable stretch of open water. (today's image was cloudier).

The water can be seen also in the distance beyond the fast ice on today's webcam image at Utqiagvík.

Title: Re: The 2019 melting season
Post by: uniquorn on March 24, 2019, 08:57:02 PM
Thanks Niall, sea ice looks like it has very little resilience there this week. Almost like it's in a washing machine.
Worldview terra modis, mar16-24  https://go.nasa.gov/2WmMAzH

Meanwhile on the Atlantic side it looks like refreeze is struggling to keep up with export.
ascat jan1-mar23 (no data for jan20)
saying goodbye to the dark line
Title: Re: The 2019 melting season
Post by: Stephan on March 24, 2019, 09:48:22 PM
Thanks for that animation. It looks like Fram export has been really active for a while now. Anyway, when I recall correctly from one of Wipneus' latest posting, Fram export is normal compared to long term averages. Is that correct?
Title: Re: The 2019 melting season
Post by: oren on March 24, 2019, 09:58:29 PM
Thanks for that animation. It looks like Fram export has been really active for a while now. Anyway, when I recall correctly from one of Wipneus' latest posting, Fram export is normal compared to long term averages. Is that correct?
That's correct, but in the last couple of years it's always been below normal.
Title: Re: The 2019 melting season
Post by: uniquorn on March 24, 2019, 10:52:31 PM
Thanks for that animation. It looks like Fram export has been really active for a while now. Anyway, when I recall correctly from one of Wipneus' latest posting, Fram export is normal compared to long term averages. Is that correct?
Unfortunately, what happens before ice reaches the Fram isn't measured yet, but if your point is that this is a normal year, I would suggest that what we may be seeing is the beginning of a relatively rapid flushing of older ice that may leave us with a significantly larger proportion of first year ice next season.
This is a better post showing old/new ice
https://forum.arctic-sea-ice.net/index.php/topic,2591.msg192368.html#msg192368
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 24, 2019, 10:59:58 PM
The main pack has been pulling away from the Alaskan coast west of Point Barrow

There's open water visible on the Nome cam also:

http://GreatWhiteCon.info/resources/arctic-webcams/#Nome
Title: Re: The 2019 melting season
Post by: magnamentis on March 24, 2019, 11:07:16 PM
Thanks for that animation. It looks like Fram export has been really active for a while now. Anyway, when I recall correctly from one of Wipneus' latest posting, Fram export is normal compared to long term averages. Is that correct?

that's right, only that i believe that the ice-mass balance is worse than ever, means the ice-mass that is exported in relation to the remaining ice-mass is higher. the part which appears to be average is probably more on the two-dimensional side or at least something along that line.
Title: Re: The 2019 melting season
Post by: uniquorn on March 25, 2019, 12:15:10 AM
Beaufort, small lift off CAA. https://go.nasa.gov/2YfyqSR
Title: Re: The 2019 melting season
Post by: Aluminium on March 25, 2019, 07:03:36 AM
March 17-24.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 25, 2019, 09:44:36 AM
There was a 162k decline in high resolution AMSR2 extent yesterday:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#Mar-25
Title: Re: The 2019 melting season
Post by: magnamentis on March 25, 2019, 11:39:04 AM
March 17-24.

why do you keep the images so cropped (small cut-out) at this time of the year it most of the action is in regions that are not in your images and since the melt onset, beside the final stage of the melting season are the most interesting ones, i suggest to post a images that cover a larger area, since i look at the orginal each day i know it's there.
Title: Re: The 2019 melting season
Post by: uniquorn on March 25, 2019, 12:34:48 PM
Thanks for that animation. It looks like Fram export has been really active for a while now. Anyway, when I recall correctly from one of Wipneus' latest posting, Fram export is normal compared to long term averages. Is that correct?
Thanks for this Stephan. The Fram export chart had been bothering me for some time as it didn't appear to correlate with what I've been seeing. Overnight I realised it is because it is a volume chart. As the exported ice gets thinner a larger area has to be exported to make up the volume.
Assuming the piomas model is correct.
edit:Colours are different on the last image due to copy from mp4 and latest gif, please check with the scale. Not a very good proof, I'll ask wipneus

Piomas mar26(or nearest) 2009-2019
Fram volume export 2019 (Wipneus describes as near normal)
Apologies to wipneus, screen grab clipped name

A comparison of ascat and piomas for 2018 here.
https://forum.arctic-sea-ice.net/index.php/topic,2417.msg189192.html#msg189192
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 25, 2019, 12:37:29 PM
why do you keep the images so cropped (small cut-out) at this time of the year it most of the action is in regions that are not in your images

What regions are of particular interest to you at the moment?
Title: Re: The 2019 melting season
Post by: bbr2314 on March 25, 2019, 01:00:45 PM
The D10 EURO forecast, if it verifies, indicates our current heat wave is only a prelude to a much larger event.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019032500/ecmwf_T850a_nhem_11.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019032500/ecmwf_z500aNorm_nhem_11.png)

The current / medium forecast would be a death-knell for much of the Arctic this summer IMO as melt ponding is going to get out of control across very many regions.
Title: Re: The 2019 melting season
Post by: uniquorn on March 25, 2019, 02:00:29 PM
Hold your horses bbr, a few hours above freezing won't be making many melt ponds;)

Lincoln sea ice crumbling into the Nares Strait. North Greenland fractures reaching out to meet the polynya shear lines. I think refreeze will struggle to keep up with this, though the fractures do ease the pressure.
Worldview, viirsbt15n, north greenland, nar24-25 last image heavily enhanced

Nares strait thread
https://forum.arctic-sea-ice.net/index.php/topic,176.msg192768.html#msg192768
Title: Re: The 2019 melting season
Post by: Aluminium on March 25, 2019, 03:36:37 PM
why do you keep the images so cropped (small cut-out) at this time of the year it most of the action is in regions that are not in your images and since the melt onset, beside the final stage of the melting season are the most interesting ones, i suggest to post a images that cover a larger area, since i look at the orginal each day i know it's there.
I'm interesting in this area. Other seas melt almost completely every year. Without active melting/freezing season here I decided post less often. Will post more frequently when action begins.
For experiment, I made gif with full area.
Title: Re: The 2019 melting season
Post by: oren on March 25, 2019, 05:01:43 PM
Thank you for these animations Aluminium. I prefer the zoomed-in version as it has better resolution, and as you say these are the interesting areas during the melting (and freezing) seasons.
Title: Re: The 2019 melting season
Post by: magnamentis on March 25, 2019, 06:50:29 PM
why do you keep the images so cropped (small cut-out) at this time of the year it most of the action is in regions that are not in your images and since the melt onset, beside the final stage of the melting season are the most interesting ones, i suggest to post a images that cover a larger area, since i look at the orginal each day i know it's there.
I'm interesting in this area. Other seas melt almost completely every year. Without active melting/freezing season here I decided post less often. Will post more frequently when action begins.
For experiment, I made gif with full area.

ok, understood, thanks for elaboration
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 26, 2019, 12:02:00 PM
Some interesting SST news from the OSI-SAF in my inbox this morning:

Quote
L3 products - two new 12-hourly 5km gridded products are being introduced:

 * OSI-203-a, based on the Metop-B AVHRR L2 SST/IST product (OSI-205-a)
 * OSI-203-b, based on the SNPP VIIRS L2 SST/IST product (OSI-205-b)

The two L3 products will replace the current multi-sensor product (OSI-203),
which will be discontinued on 10 September 2019. Users are therefore
encouraged to start using the OSI-203-a and OSI-203-b products instead of
OSI-203.

All the new products are in GHRSST compliant netCDF4 format and cover the
High Latitudes seas and ice areas north of 50N. The existing OSI-205-a is
poleward of 50N and 50S. The products are available on FTP and EUMETCast.
More details about the products are available here:

http://www.osi-saf.org/?q=content/sst-products
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 26, 2019, 06:18:14 PM
Another > 100k drop in high res AMSR2 extent:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#comment-274108
Title: Re: The 2019 melting season
Post by: El Cid on March 26, 2019, 08:57:31 PM
Another > 100k drop in high res AMSR2 extent:


If you were a stock trader you should sell this one short NOW!  :)
Title: Re: The 2019 melting season
Post by: jdallen on March 27, 2019, 02:54:17 AM
A folks?!  About that uptick in extent that we had in the Bering a bit ago?!

;)
Title: Re: The 2019 melting season
Post by: jdallen on March 27, 2019, 03:06:27 AM
On the other side of things, the Barents doesn't look a whole lot healthier.

This shot is from the 26th.  If you go back a day, the "Atlantic Front" ice killing zone NW and N of Svalbard is very visible.

Today's shot shows very large expanses S and E of Franz Josef threading out, and what might be the beginnings of another "hot zone"  to the west of the island in the strait between the two archipelagos.
Title: Re: The 2019 melting season
Post by: uniquorn on March 27, 2019, 01:27:48 PM
On the other side of things, the Barents doesn't look a whole lot healthier. <sn>
Both ecmwf and gfs forecasting below 960hPa storms in the barentsz on saturday, though, in extent terms, it might just suck more older ice out of the CAB
https://tinyurl.com/yyledwze

edit: Mercator model indicating the underlying 34m current north and northwest of FJL hasn't quite cooled down over the freezing season. Jan1-mar25. Open water due west of FJL may be wind driven.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 27, 2019, 04:21:25 PM
High resolution AMSR2 extent has plunged 425 thousand square kilometres over the last four days:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#comment-274372
Title: Re: The 2019 melting season
Post by: dnem on March 27, 2019, 05:22:00 PM
How rare is it to see a full 10 day GFS run on the Reanalyzer predicting 2M anomalies in the arctic above 6 deg C (ok, a couple of drops to 5.9) and as high as 7.6? I don't recall seeing as anomalous a forecast as the current one. Or do I just not recall?
Title: Re: The 2019 melting season
Post by: Pavel on March 27, 2019, 06:31:58 PM
I can't remember such 7.6 degrees anomalies. Eyeballing the land I also see it more gray than usual at this time of year. Looks the melt season promises to be exciting since the freeze season was boring for me
Title: Re: The 2019 melting season
Post by: jdallen on March 27, 2019, 07:31:30 PM
High resolution AMSR2 extent has plunged 425 thousand square kilometres over the last four days:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#comment-274372
Considering peripheral ice quality, a loss of another half million over the next 7-10 days before it slows would be unsurprising.
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on March 27, 2019, 07:33:49 PM
How rare is it to see a full 10 day GFS run on the Reanalyzer predicting 2M anomalies in the arctic above 6 deg C (ok, a couple of drops to 5.9) and as high as 7.6? I don't recall seeing as anomalous a forecast as the current one. Or do I just not recall?

I don't remember the anomalies being so high.
Title: Re: The 2019 melting season
Post by: sark on March 27, 2019, 07:56:08 PM
How rare is it to see a full 10 day GFS run on the Reanalyzer predicting 2M anomalies in the arctic above 6 deg C (ok, a couple of drops to 5.9) and as high as 7.6? I don't recall seeing as anomalous a forecast as the current one. Or do I just not recall?

November 2016.

Maybe February 2018.
Title: Re: The 2019 melting season
Post by: dnem on March 28, 2019, 12:21:37 PM
How rare is it to see a full 10 day GFS run on the Reanalyzer predicting 2M anomalies in the arctic above 6 deg C (ok, a couple of drops to 5.9) and as high as 7.6? I don't recall seeing as anomalous a forecast as the current one. Or do I just not recall?

November 2016.

Maybe February 2018.

Ok, but it was more the entire 10 day run above 6 deg that struck me as extreme.  I would guess it is certainly ONE of the most anomalous 10 day runs in many years, anyway.
Title: Re: The 2019 melting season
Post by: uniquorn on March 28, 2019, 01:30:57 PM
As mobile ice has been driven off the Laptev fast ice by southerly winds over the last week or so here is a historical look at the Laptev for mar28 (or close clear-ish day) from 2000-2019 for comparison. (Worldview terra modis)

edit: Added buoy temperature in the Beaufort since sep2018. Relatively warm today, though still cold, as it's closer to ice surface temperature rather than air. (subs please check   ;) ) This will affect the 'preconditioning' that bbr mentioned upthread.
http://www.whoi.edu/page.do?pid=163096
Title: Re: The 2019 melting season
Post by: uniquorn on March 29, 2019, 11:38:46 AM
Update on Utqiagvik (barrow). Land fast breaking away to the east yesterday.
Worldview terra modis, mar27-28
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 29, 2019, 01:47:05 PM
The decline continues, albeit at a rather reduced rate. JAXA is now flirting with 3rd place:

Title: Re: The 2019 melting season
Post by: Juan C. García on March 29, 2019, 03:19:25 PM
The decline continues, albeit at a rather reduced rate. JAXA is now flirting with 3rd place:
2016 is now 79K km2 above 2019, but it will be the new lowest leader in a couple of days. So 2019 could be 3rd lowest tomorrow, but I think that it will be 4th lowest the day after.
Title: Re: The 2019 melting season
Post by: Juan C. García on March 30, 2019, 05:36:10 AM
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

March 29th, 2019:
     13,588,813 km2, a century drop of -113,286 km2.
     2019 is 3th lowest on record.
     (2012 highlighted)
With the century drop, 2019 can be the lowest on record tomorrow!
[2019 will be the lowest if it drops 28K km2 tomorrow]
Title: Re: The 2019 melting season
Post by: Aluminium on March 30, 2019, 06:20:50 AM
March 22-29.
Title: Re: The 2019 melting season
Post by: El Cid on March 30, 2019, 08:41:34 AM
Houston, Houston!

We're going to have a problem - given the weather forecast. Especially the Bering and the Chukchi.
Title: Re: The 2019 melting season
Post by: Stephan on March 30, 2019, 09:10:46 AM
...and the ice in Kara Sea also does not look very healthy (see Aluminium's animation above)
Title: Re: The 2019 melting season
Post by: b_lumenkraft on March 30, 2019, 09:21:25 AM
...and the ice in Kara Sea also does not look very healthy (see Aluminium's animation above)

Neither does Laptev sea. :(
Title: Re: The 2019 melting season
Post by: oren on March 30, 2019, 09:30:06 AM
Looking at the regional AMSR2 extent charts, it appears 2019 is very low in the Bering (as was 2018), somewhat low in Baffin, rather high in Okhotsk, and quite typical in all other regions.
Despite high temps it's very hard to make a sustained drop in Kara and Laptev before mid-May, and in Chukchi before mid-April, as the ice is quite thick and any wind change closes the gaps in the ice. But Okhotsk, Bering and Barents are vulnerable enough.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 30, 2019, 10:28:50 AM
2019 will be the lowest if it drops 28K km2 tomorrow

Based on the high res AMSR2 area that seem highly likely to happen:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#Mar-30
Title: Re: The 2019 melting season
Post by: Archimid on March 30, 2019, 12:35:24 PM
Early melting season cliffs are scary. Hopefully things get better after this event is over.

Attached, Bering sea ASI volume from 2000 to latest release.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on March 30, 2019, 01:13:41 PM
...and the ice in Kara Sea also does not look very healthy (see Aluminium's animation above)

Neither does Laptev sea. :(

Nor the Lincoln sea. So basically the entire arctic periphery.

Other than that though...
Title: Re: The 2019 melting season
Post by: magnamentis on March 30, 2019, 01:33:55 PM
The decline continues, albeit at a rather reduced rate. JAXA is now flirting with 3rd place:
2016 is now 79K km2 above 2019, but it will be the new lowest leader in a couple of days. So 2019 could be 3rd lowest tomorrow, but I think that it will be 4th lowest the day after.

since your predictions are so much better than mine i didn't dare to say it loud, but my first thought last night was: "except" (if it follows the path of 2016 )

looking at the temps for the today and tomorrow combined with southerly winds in bering plus the fact that not one region that is already in the reach of melting events is currently cold, i'd say that the next drop will be similar to today's but with my luck/skills i'm perhaps wrong now that i mentioned it LOL

 8)
Title: Re: The 2019 melting season
Post by: Tor Bejnar on March 30, 2019, 02:05:25 PM
I have a vague recollection of someone (a year or two ago) comparing early ice melt with season-complete ice melt and found no correlation.  Can someone with data run a comparison and enlighten us?

(It's the 'only' hope we have of my 2013 projection of ice freedom in 2019 not coming to pass.)
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 30, 2019, 02:11:40 PM
Attached, Bering sea ASI volume from 2000 to latest release.

Bering Sea ice area for the AMSR2 era:

Title: Re: The 2019 melting season
Post by: Klondike Kat on March 30, 2019, 02:29:53 PM
I have a vague recollection of someone (a year or two ago) comparing early ice melt with season-complete ice melt and found no correlation.  Can someone with data run a comparison and enlighten us?

(It's the 'only' hope we have of my 2013 projection of ice freedom in 2019 not coming to pass.)

I have found the same thing.  Early melt in 2007 was slightly below average, 2106 was well below average, and 2012 was one of the lowest.  Early season melt was highest during the 1980s.  Consequently, their is a slight correlation with sea ice maximum; namely the higher the maximum, the higher the early season melt.  There was no correlation with either the minimum or total season ice loss.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 30, 2019, 02:33:53 PM
There was no correlation with either the minimum or total season ice loss.

Gotta link?
Title: Re: The 2019 melting season
Post by: Gray-Wolf on March 30, 2019, 03:39:22 PM
I think we all have to accept that 'today' ,early season, is very different to 1980's ,early season?

Look at the amounts of 'peripheral ice' that there was to be got rid of prior to central basin melt back in the 80's? You would see big number losses as the easy ice went, early doors, now we have very little 'peripheral ice' in Bering/Barentsz/Kara so rely on St Lawrence/Hudson and the strip down the east coast of Greenland for all of our early melt?

These days if we saw big number melt in the first weeks of melt season I'd say it was a big portent for the evolution of the season if only for the space it provided for ice to fracture into lessening floe size and allowing waters to warm early?
Title: Re: The 2019 melting season
Post by: Tor Bejnar on March 30, 2019, 04:00:12 PM
While I agree with GW's last paragraph - early losses should set the stage for later losses - we're 'stuck' with KK's anecdotal description of recent early-loss years not being the same as greatest-loss years. 
Title: Re: The 2019 melting season
Post by: wdmn on March 30, 2019, 04:12:55 PM
I think we all have to accept that 'today' ,early season, is very different to 1980's ,early season?

Look at the amounts of 'peripheral ice' that there was to be got rid of prior to central basin melt back in the 80's? You would see big number losses as the easy ice went, early doors, now we have very little 'peripheral ice' in Bering/Barentsz/Kara so rely on St Lawrence/Hudson and the strip down the east coast of Greenland for all of our early melt?

These days if we saw big number melt in the first weeks of melt season I'd say it was a big portent for the evolution of the season if only for the space it provided for ice to fracture into lessening floe size and allowing waters to warm early?

In other words it may be more useful to consider percent loss of total?
Title: Re: The 2019 melting season
Post by: Juan C. García on March 30, 2019, 04:24:40 PM
From my point of view, the air temperatures and the high pressure (associated with them) in June and July will be decisive. We have been lucky not to have warm temperatures on both months on the last 6 years.
I am hoping that there is a negative feedback making both months colder than usual the worst years. But that is just hope. We will have to wait and see.
["Colder than usual" meant not following the trend of being warmer, like 2007, 2011 and 2012].
Title: Re: The 2019 melting season
Post by: Klondike Kat on March 30, 2019, 05:08:54 PM
I think we all have to accept that 'today' ,early season, is very different to 1980's ,early season?

Look at the amounts of 'peripheral ice' that there was to be got rid of prior to central basin melt back in the 80's? You would see big number losses as the easy ice went, early doors, now we have very little 'peripheral ice' in Bering/Barentsz/Kara so rely on St Lawrence/Hudson and the strip down the east coast of Greenland for all of our early melt?

These days if we saw big number melt in the first weeks of melt season I'd say it was a big portent for the evolution of the season if only for the space it provided for ice to fracture into lessening floe size and allowing waters to warm early?

In other words it may be more useful to consider percent loss of total?

Not really.  The maximum is only 10% lower than in the 1980s (last five year NSIDC extent vs 1979-90).  This is small compared to early sea losses than can vary by 100% or more.  There is no correlation between early sea ice losses and previous years ice growth or change in the maximum or minimum.  Al this is comparing the early loss to the maximum.  If we were to just compare the last two weeks in March, recent losses are less, due to later maxima in recent years.

All in all, it appears to mostly weather related.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 30, 2019, 06:42:09 PM
Hi KK,

All in all, it appears to mostly weather related.

Did I blink and miss your link(s)?
Title: Re: The 2019 melting season
Post by: Klondike Kat on March 31, 2019, 12:15:37 AM
Hi KK,

All in all, it appears to mostly weather related.

Did I blink and miss your link(s)?

The data is all right here:

https://nsidc.org/arcticseaicenews/sea-ice-tools/

You may need to do a little math of your own though, but you should come to the same conclusions.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 31, 2019, 12:42:27 AM
You may need to do a little math of your own though, but you should come to the same conclusions.

Strangely enough I've done a bit of maths (as we call the subject here in the once Great Britain), and a fair bit of programming too.

Perhaps you wouldn't mind enlightening me further concerning how you came to your particular conclusions? Methodology as well as raw data would be helpful, for example.
Title: Re: The 2019 melting season
Post by: Klondike Kat on March 31, 2019, 01:24:53 AM
You may need to do a little math of your own though, but you should come to the same conclusions.

Strangely enough I've done a bit of maths (as we call the subject here in the once Great Britain), and a fair bit of programming too.

Perhaps you wouldn't mind enlightening me further concerning how you came to your particular conclusions? Methodology as well as raw data would be helpful, for example.

The raw data is in the previous link.  I have plotted at the recent melt compared to the annual maximum, minimum, previous season ice growth, and change in ice maximum from the previous season.  No correlation exists in any of the comparisons.  Early season melt is no indication of what is to come later in the season.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on March 31, 2019, 03:42:12 AM
This took quite the dive.
Went from 8th or 9th lowest to 4th or 5th pretty quickly.
Title: Re: The 2019 melting season
Post by: jdallen on March 31, 2019, 04:53:25 AM
...and the ice in Kara Sea also does not look very healthy (see Aluminium's animation above)

Neither does Laptev sea. :(
Conditions in the Laptev and Kara are not exceptional for the date.  The key regions right now remain the Bering, Chukchi and Barents.
Title: Re: The 2019 melting season
Post by: Juan C. García on March 31, 2019, 07:38:52 AM
I have a vague recollection of someone (a year or two ago) comparing early ice melt with season-complete ice melt and found no correlation.  Can someone with data run a comparison and enlighten us?

(It's the 'only' hope we have of my 2013 projection of ice freedom in 2019 not coming to pass.)
There were some comments about this on NSIDC Analysis.

By memory, the lowest years on September are 2005-2007, 2010-2012 and 2015-2018. Looking at the ice on March on those years, the great exemption is 2012, that had more ice than 2010's average on March and end up being the lowest on September (and by far). But all the other years that were low on September, they were also low on March.
So, I don't think that low values on March will mean that we will not have a low record on September. If we have melting conditions on June-August, 2019 will be terrible.
2019 is going to make me eat my nails, with the -165,712 km2 drop that we have today and the heat that we still have on the Arctic.

P.S.: I didn't include 2010 on the graph and it is close to 2012 on March. So there is another year that it was above average on March and end up with a low value on September.
Title: Re: The 2019 melting season
Post by: miki on March 31, 2019, 07:45:04 AM
If we have melting conditions on June-August, 2019 will be terrible.
2019 is going to make me eat my nails, with the -165,712 km2 drop that we have today and the heat that we still have on the Arctic.

I'm there with you. Thanks for your postings.
Title: Re: The 2019 melting season
Post by: Pmt111500 on March 31, 2019, 09:23:35 AM
Looks like the warmish Gulf of Alaska seeps to Bering Sea through the Aleut Channels, a normal Pacific sub-polar gyre is active. This is by no means a new thing in anything but the relative warmth of the waters.

https://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=-166.80,48.41,1025
Title: Re: The 2019 melting season
Post by: bbr2314 on March 31, 2019, 10:32:14 AM
I think we are seeing a possible perfect storm forming this year. I am very surprised by this occurring after the widespread record snows across North America this year. We have seen the most sustained March warmth across the Arctic to date of any recent year, perhaps excluding 2016 (but the focus of the heat that year was on the ATL not the PAC).

This weather is important IMO because it is following order of operations to obtain possible record summer extent minimum. Anomalous warmth focused on the Pacific periphery at a time of year when it should still be gaining mass is now sufficient to result in outright melt rather than mere cessation of gains. The Pacific heat will be complemented by rising temps across the ESS and Chukchi and Kara, as well. IMO, this is pointing toward a very early volume max for the Arctic and a record early start to steep extent losses. Whether this results in a record minimum remains to be seen.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 31, 2019, 10:50:53 AM
I have plotted at the recent melt compared to the annual maximum, minimum, previous season ice growth, and change in ice maximum from the previous season.

Great! Where can I see those plots?

Quote
No correlation exists in any of the comparisons.  Early season melt is no indication of what is to come later in the season.

An introduction for the "citizen scientist" to the concept that correlation isn't necessarily all it's cracked up to be:

https://www.researchgate.net/publication/331812193_Hannah_Fry%27s_Hello_World_and_the_Example_of_Algorithm_Bias
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 31, 2019, 10:53:14 AM
To add to Juan's JAXA graph, the plunge has resumed:

http://GreatWhiteCon.info/2019/03/facts-about-the-arctic-in-march-2019/#Mar-31
Title: Re: The 2019 melting season
Post by: Richard Rathbone on March 31, 2019, 02:19:25 PM
I have plotted at the recent melt compared to the annual maximum, minimum, previous season ice growth, and change in ice maximum from the previous season.

Great! Where can I see those plots?


Failure to disprove a null hypothesis isn't that interesting. Its you that needs to be coming up with the plots that do disprove it, not KK with the plots that don't.
Title: Re: The 2019 melting season
Post by: dnem on March 31, 2019, 02:35:25 PM
We don't need to look at plots or correlation coefficients on either side. We are dealing with WAY too little data here to make any conclusions whatsoever.  2012 proves this point. This week's weather and loses can only be bad for the ice and set up some level of pre-conditioning.  But it will be, as always, the weather that determines the ultimate minimum.  And nobody can predict that.
Title: Re: The 2019 melting season
Post by: Archimid on March 31, 2019, 02:42:57 PM
Just did a quick correlation of max and min extent. I get 0.79 correlation coefficient. But then again statistics are not needed because both max and minimum are part of the same system were each one depends on the other. Correlation is expected and not very useful.
Title: Re: The 2019 melting season
Post by: Klondike Kat on March 31, 2019, 03:14:44 PM
Just did a quick correlation of max and min extent. I get 0.79 correlation coefficient. But then again statistics are not needed because both max and minimum are part of the same system were each one depends on the other. Correlation is expected and not very useful.

It comes as no surprise that in a connected system, the maximum and minimum are correlated.  As you state, that is not very useful.  Early season melt is not very indicative of the full season, as dnem pointed out.  2012 had the lowest early season melt.  By comparison, early season melt in 2002 was quite high - 2019 is actually paralleling 2002 quite closely.  However, as stated by dnem (and repeated by others), the weather will determine the ultimate minimum.

https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 31, 2019, 04:20:28 PM
Its you that needs to be coming up with the plots that do disprove it, not KK with the plots that don't.

KK hasn't come up with any plots at all yet, that I have seen at least. Or even a "scientific" statement of his or her hypothesis. Perhaps you could elucidate for me?
Title: Re: The 2019 melting season
Post by: Shared Humanity on March 31, 2019, 04:36:20 PM
Thank the Goddess that KK has thoroughly refuted any connection to early season melt (loudly and definitively I might add  ;) ) with final minimums or else I might start getting worried.
Title: Re: The 2019 melting season
Post by: Shared Humanity on March 31, 2019, 04:43:33 PM
I, for one, will be keeping a very close eye on the Kara and Laptev as I am developing a persistent concern about the Atlantification of the Arctic.
Title: Re: The 2019 melting season
Post by: Shared Humanity on March 31, 2019, 04:50:09 PM
I do generally hold the opinion that we should all be a little more circumspect about making definitive statements here as even the most rigorous climate scientists express uncertainty about what we can expect. If someone here chooses to toss aside caution and insist that something is the case, they should expect to be asked to show their research. If they fail to do so, it should come as no surprise if most here discount what they say.
Title: Re: The 2019 melting season
Post by: FishOutofWater on March 31, 2019, 04:57:34 PM
In 2012 storms dispersed the ice in March, making the extent situation look much better than it was in reality. The thin dispersed ice rapidly melted in May and June. The situation this year is extremely bad because the thick ice is piled up on Greenland at the exit to the Fram strait and storms are thinning the ice at the margins at the Barents, Kara and Chukchi seas.

When we compare years it is most helpful to look at more than just the extent graphs and look at the thickness distribution and the salinity and heat at the 100m and 300m levels.

Yes, the weather this year will make the difference, but it looks very bad so far for sea ice. What we have seen in the past few weeks is the worst possible set up for a disastrous collapse this summer if the weather is warm and sunny.

And the CFS model predicts exactly that for the next 3 months, with a strong jet stream over the northern Pacific and a stronger than normal Aleutian low coupled with warm sunny high pressure over the western Arctic and Alaska.

This pattern ties in with the sudden stratospheric warming in late December coupled with the El Niño and active overturning in the Labrador sea.

All long range forecasts are subject to failure but this is forecast is about as bad as it gets for the sea ice.
Title: Re: The 2019 melting season
Post by: gerontocrat on March 31, 2019, 05:08:31 PM
I, for one, will be keeping a very close eye on the Kara and Laptev as I am developing a persistent concern about the Atlantification of the Arctic.
Recent area loss in the Kara and Laptev looks like more than the March wobbles up and down.
Over the next 3 days it looks like there will be an extra strong pulse of warmth from the south in the region.
Title: Re: The 2019 melting season
Post by: meddoc on March 31, 2019, 05:14:11 PM
I've done NSIDC SIE Graphs; and current Graph prolonged by 2012 Melting Graph would take us
easy beneath 3 M km2.
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on March 31, 2019, 05:15:53 PM
Question, why isn't the DMI showing that much of an anomaly when there is a huge anomaly going on right now?

http://ocean.dmi.dk/arctic/meant80n.uk.php

Title: Re: The 2019 melting season
Post by: Klondike Kat on March 31, 2019, 05:19:36 PM
Its you that needs to be coming up with the plots that do disprove it, not KK with the plots that don't.

KK hasn't come up with any plots at all yet, that I have seen at least. Or even a "scientific" statement of his or her hypothesis. Perhaps you could elucidate for me?

If you could elucidate me on how to post my own plots, I would be grateful.  I have the insert image icon, but am unable to copy and paste my graphs.  Still, it was not that difficult to plot the NSIDC data.
Title: Re: The 2019 melting season
Post by: Archimid on March 31, 2019, 05:23:02 PM
I think that is because DMI covers temps North of 80 and N80 is where the only cold anomalies are in the Arctic right now and where there are the least hot anomalies.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on March 31, 2019, 05:24:55 PM
If you could elucidate me on how to post my own plots, I would be grateful.  I have the insert image icon, but am unable to copy and paste my graphs.  Still, it was not that difficult to plot the NSIDC data.

Screenshot?

Command + Shift + 4 then select area on Mac.

For Windows, there are apps for that (google "Snipping Tool").
Title: Re: The 2019 melting season
Post by: Darvince on March 31, 2019, 07:31:42 PM
Despite high temps it's very hard to make a sustained drop in Kara and Laptev before mid-May, and in Chukchi before mid-April, as the ice is quite thick and any wind change closes the gaps in the ice. But Okhotsk, Bering and Barents are vulnerable enough.
Careful, or Mother Nature might see your post and decide that this is the year to start bringing Kara/Laptev melt earlier. ;)

Question, why isn't the DMI showing that much of an anomaly when there is a huge anomaly going on right now?

http://ocean.dmi.dk/arctic/meant80n.uk.php
The DMI chart is for 80N+ only, and gives equal weight to each degree rather than all area above 80N, so it will represent mostly the conditions right around the pole, which is the only area of the Arctic below average right now. Based on model forecasts out to day-5 it should rise substantially in two or three days, as the cold heads over towards the Beaufort and the heat all around takes its place.
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 31, 2019, 08:07:32 PM
If you could elucidate me on how to post my own plots, I would be grateful.  I have the insert image icon, but am unable to copy and paste my graphs.  Still, it was not that difficult to plot the NSIDC data.

If you need to do a screenshot, it depends on your operating system. On Windows you can use the "Prt Sc" key then paste into Paint and edit if necessary. I prefer Jing though. On Linux I use Shutter.
Title: Re: The 2019 melting season
Post by: Pmt111500 on March 31, 2019, 08:12:04 PM
I think that is because DMI covers temps North of 80 and N80 is where the only cold anomalies are in the Arctic right now and where there are the least hot anomalies.

Yea, wish there was a simple graph like that with true weights down to 67N , that would reach the 1960s at least so it'd represent better the anomalies.
Title: Re: The 2019 melting season
Post by: oren on March 31, 2019, 08:51:50 PM
If you could elucidate me on how to post my own plots, I would be grateful.  I have the insert image icon, but am unable to copy and paste my graphs.  Still, it was not that difficult to plot the NSIDC data.

Screenshot?

Command + Shift + 4 then select area on Mac.

For Windows, there are apps for that (google "Snipping Tool").
Insert image is for images on the web that have hyperlinks. If you mean your own graph on your computer, paste them into Paint, save them (best is width <700 pixels), and then attach them with your post (in attachments and other options, below the text box. Up to 4 files per post).
Title: Re: The 2019 melting season
Post by: FishOutofWater on March 31, 2019, 09:04:32 PM
Climate reanalyzer's GFS model based analysis for today gives an Arctic temperature anomaly of 7.5 C (13.5ºF). The attached image shows how there's a cold core around the pole surrounded by a very warm Arctic. The warmth over the Arctic has been advected from the north Pacific and north Atlantic oceans by intense storms and blocking highs. Blocking over Alaska has persistently recurred for months bringing very warm weather with it to Alaska and the Bering sea.
Title: Re: The 2019 melting season
Post by: Stephan on March 31, 2019, 09:24:06 PM
You may need to do a little math of your own though, but you should come to the same conclusions.

Strangely enough I've done a bit of maths (as we call the subject here in the once Great Britain), and a fair bit of programming too.

Perhaps you wouldn't mind enlightening me further concerning how you came to your particular conclusions? Methodology as well as raw data would be helpful, for example.

The raw data is in the previous link.  I have plotted at the recent melt compared to the annual maximum, minimum, previous season ice growth, and change in ice maximum from the previous season.  No correlation exists in any of the comparisons.  Early season melt is no indication of what is to come later in the season.

Please refer to my posting last year where I plotted the average monthly losses vs. the JAXA minimum and found almost no correlation (the best with R² = 0.79 is valid for July; but July is the month with the biggest losses...)
https://forum.arctic-sea-ice.net/index.php/topic,2285.msg157248.html#msg157248
Title: Re: The 2019 melting season
Post by: HapHazard on March 31, 2019, 09:36:49 PM
Interesting times. I'm actually starting to feel a bit anxious, and it's much too early in the melt season for that.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on March 31, 2019, 10:31:22 PM
Thanks, Stephan (2 posts up), for putting a link to my "vague recollection (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg193293.html#msg193293)"! Your post being only 10 months ago shows why 'recollection' is not a good substitute for posted analyses, so I also appreciate Jim Hunt for asking!
Title: Re: The 2019 melting season
Post by: Jim Hunt on March 31, 2019, 11:40:00 PM
Please refer to my posting last year

Thanks Stephan. Note that I don't doubt that "weather" will have a big influence on the 2019 minimum. Particularly the advent of melt ponds.

However as Tor points out, I too am a fan of "posted analyses" rather than unsupported "hearsay".
Title: Re: The 2019 melting season
Post by: Thomas Barlow on March 31, 2019, 11:49:57 PM
Pretty bad turn of events in just a week.
Showing this year and previous lower years for this day.
Not much in it at this point.

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Title: Re: The 2019 melting season
Post by: Killian on April 01, 2019, 10:32:57 AM
I, for one, will be keeping a very close eye on the Kara and Laptev as I am developing a persistent concern about the Atlantification of the Arctic.
Recent area loss in the Kara and Laptev looks like more than the March wobbles up and down.
Over the next 3 days it looks like there will be an extra strong pulse of warmth from the south in the region.

Overall, the loss from March 12 to 31 appears, after using the JAXA interactive graph, to be the fastest loss for that period (or 15 to 31, slightly higher, if you prefer) on record. Likely nothing, but that's a lot of melt for March. It's also record lows for the 29th ~ 31st, and likely to continue to be for a few days given the flatness of the curves above it, the rate of decline, the warming of the Arctic in recent days and the approaching negative AO, which should bring in some warmer air.

Meaningful? Who knows. Early July is about the soonest one can get a very slightly solid sense of where things are headed. At least, imo.

Cheers
Title: Re: The 2019 melting season
Post by: Gray-Wolf on April 01, 2019, 11:42:17 AM
The Atlantification/Pacification of the basin is a growing thing not a seasonal intrusion. Once the Halocline is either flooded over or mixed out it'll take a nice age to rebuild the depth we had as recently as the noughties?

The loss of that layer allows a very different ocean , and processes ,to evolve in line with all the other Oceans of the World.

My concern is , like so much else in nature, it is not a straight line graph of change but one with very rapid periods of alteration?

Title: Re: The 2019 melting season
Post by: meddoc on April 01, 2019, 12:45:27 PM
I made the Graph Extension for SIE Minimum as of 2019.03.30 extended by 2012 Melting Pattern.
This would take us at about 2 M km2. Could be even worse than that Curve, given recent Cliffs.

PS: Needs to be viewed in Full Size to see 2019 orange curve at 2019.03.30.
Title: Re: The 2019 melting season
Post by: uniquorn on April 01, 2019, 01:18:56 PM
From the data thread:
The weather is going to shift to deep lows in the Labrador sea over the next week. That's going to increase ice export and fresh water out of the Labrador sea and increase deep water formation where the cold air blasts off of eastern Canada onto the shelf edge. The coming weather will speed up ice loss in the Labrador and Greenland seas.
amsr2-uhh, baffin/labrador mar1-31
Title: Re: The 2019 melting season
Post by: oren on April 01, 2019, 02:21:37 PM
I made the Graph Extension for SIE Minimum as of 2019.03.30 extended by 2012 Melting Pattern.
This would take us at about 2 M km2. Could be even worse than that Curve, given recent Cliffs.

PS: Needs to be viewed in Full Size to see 2019 orange curve at 2019.03.30.
It's very difficult to replicate the 2012 loss without the high SIE it started with, especially in the Bering.
Not saying it couldn't happen but the extrapolation ia not entirely valid.
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 01, 2019, 02:37:28 PM
Current NSIDC ice loss from maximum is fourth highest (after 79, 90, and 88).  None of those years were particularly excessive when it came to either minimum extent or total ice loss.  Conversely, 2012, which had the greatest seasonal ice loss, had very little loss through the month of March.  Interestingly, 1999 had no ice loss through March, as the maximum occurred on March 31.  Drawing any seasonal conclusion from early season ice loss seems foolish.

Title: Re: The 2019 melting season
Post by: sark on April 01, 2019, 03:00:50 PM
Virtually the entire air column is flowing from the east over the Bering Sea.  Back across the dateline.  From about 1000mb to 70mb.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 01, 2019, 03:37:11 PM
Now lowest.
.
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Title: Re: The 2019 melting season
Post by: jdallen on April 01, 2019, 04:53:58 PM
I made the Graph Extension for SIE Minimum as of 2019.03.30 extended by 2012 Melting Pattern.
This would take us at about 2 M km2. Could be even worse than that Curve, given recent Cliffs.

PS: Needs to be viewed in Full Size to see 2019 orange curve at 2019.03.30.
e
It's very difficult to replicate the 2012 loss without the high SIE it started with, especially in the Bering.
Not saying it couldn't happen but the extrapolation ia not entirely valid.
Valid.

The volatility of extent makes it difficult to compare specific years. I think we'd be better off examining 2012 volume loss and attempt to extrapolate extent from that based on estimations of average thickness.
Title: Re: The 2019 melting season
Post by: oren on April 01, 2019, 06:20:10 PM
Drawing any seasonal conclusion from early season ice loss seems foolish.
On the other hand, completely ignoring early season losses on the grounds of low correlation may not be so wise, especially when said early losses take the ice into record territory. It does not necessarily mean the melting season will be exceptional, but it does increase the risk.
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 01, 2019, 06:30:41 PM
Drawing any seasonal conclusion from early season ice loss seems foolish.
On the other hand, completely ignoring early season losses on the grounds of low correlation may not be so wise, especially when said early losses take the ice into record territory. It does not necessarily mean the melting season will be exceptional, but it does increase the risk.

That is true.  On the other hand, it may just mean ice that would melt regardless has melted earlier than expected.  Baring any exceptional summer weather (a la 2012), this may just even out in the coming months (like 2002).  We shall see.
Title: Re: The 2019 melting season
Post by: Archimid on April 01, 2019, 06:59:56 PM
Early melt has so far not been indicative of the magnitude of the losses during the melting season, however an exceptionally bad melting season is made worse by a bad start. I much rather start the season with the highest extent and volume possible.
Title: Re: The 2019 melting season
Post by: uniquorn on April 01, 2019, 09:41:41 PM
We wouldn't be on this thread if changing one variable could reliably forecast minimum extent ;)
Amongst many other variables, early extent loss allows rougher sea conditions which affect mixing, probably leading to higher surface salinity (or closer to surface) and surface temperature in immediate and adjoining areas, depending on other variables (currents, wind....). Obvious examples are Bering/Chukchi and Barentsz/Laptev/CAB
edit: Agree with Gray-Wolf above - likely to alter the halocline at some point. It's only 30m deep.
Mercator(model) salinity 0m, feb1-mar31  http://bulletin.mercator-ocean.fr/
forgot scale.
Title: Re: The 2019 melting season
Post by: rboyd on April 01, 2019, 10:44:47 PM
Trying to short-term predict a complex chaotic system like the Arctic is a mugs game. We know that the heat imbalance is rising, and we know that there are a lot of possible "cliffs" for values to fall down, but we also know that there are some short-term negative feedbacks and sheer randomness that mess with the predictions. The trend is there, but also a lot of noise. Then, in addition we have outside influences such as the ENSO.

At some point the Arctic sea ice will go "poof", probably quite soon given the trends, and once it goes poof there is a high probability that it will stay poofed given the probable feedbacks that will be triggered. We may all then be very much f**d, so I am personally hoping for (not predicting) a slow move to the poof event.

Title: Re: The 2019 melting season
Post by: magnamentis on April 01, 2019, 11:15:55 PM
Early melt has so far not been indicative of the magnitude of the losses during the melting season, however an exceptionally bad melting season is made worse by a bad start. I much rather start the season with the highest extent and volume possible.

it will happen once we shall see a sunny spring/summer where the reduced albedo will have a max possible impact. until now we were just dodging the canon ball because summers were misty, foggy, cloudy or all of them.

whatever we think, weather will make the difference while once already low in spring and the waters around taking in heat/insolation in the periphery is already not negligible, it will look a bit or a lot different and winds are also easier to  build up once a lot of warm water surrounds the remaing around 0C area.
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 02, 2019, 12:25:33 AM
Sea surface height maps are affected by differences in air pressure but there's consistent evidence that the volume of fresh water in the Beaufort high's fresh water dome has declined while salt water has flowed into the Siberian side of the Arctic, increasing the salinity of the Atlantic layer and the intrusion of salty water at 30m to 300m along the Siberian shelf edge.

We haven't merely been having warm weather in the Arctic. Winds have favored the influx of Atlantic and Pacific waters and the outflow of ice and fresh water through the Fram and Nares straits.(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20180331%2Farc%2FA%2Fpsy4qv3r1_20180331_arc_sea_surface_height_0m.png&hash=632f78900217592b7f8fbc2f34641276)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20190331%2Farc%2FA%2Fpsy4qv3r1_20190331_arc_sea_surface_height_0m.png&hash=1fa0700fb7d118e7f5c5804a18a86a3b)

This is an extraordinarily bad start to the melting season. Maybe the weather will give the ice a break come June and July, but so far the models are predicting a stronger than normal peak melt season. Let's hope that they are wrong, but based on the present SST and atmospheric circulation patterns, the model forecasts appear to make good sense to me. Early warmth and albedo loss will tend to continue into the summer months because albedo loss is like a negative snowball for Arctic heat.
Title: Re: The 2019 melting season
Post by: jdallen on April 02, 2019, 12:41:41 AM
Sea surface height maps are affected by differences in air pressure but there's consistent evidence that the volume of fresh water in the Beaufort high's fresh water dome has declined while salt water has flowed into the Siberian side of the Arctic, increasing the salinity of the Atlantic layer and the intrusion of salty water at 30m to 300m along the Siberian shelf edge.

We haven't merely been having warm weather in the Arctic. Winds have favored the influx of Atlantic and Pacific waters and the outflow of ice and fresh water through the Fram and Nares straits.

This is an extraordinarily bad start to the melting season. Maybe the weather will give the ice a break come June and July, but so far the models are predicting a stronger than normal peak melt season. Let's hope that they are wrong, but based on the present SST and atmospheric circulation patterns, the model forecasts appear to make good sense to me. Early warmth and albedo loss will tend to continue into the summer months because albedo loss is like a negative snowball for Arctic heat.
That drop in albedo concerns me as well.  Where you have open water you don't need melt ponds.

Also of concern, that open water and warmer peripheral temperatures means moisture is dropping out over the central seas rather than the periphery, along with its charge of heat.

I'm in full agreement with FooW;  if we don't get a cool down or extensive spring cloudiness,this season has a good chance of smashing 2012.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 02, 2019, 02:12:56 AM
Trying to short-term predict a complex chaotic system like the Arctic is a mugs game.

I propose to rename ASIF "Mugs Musings".
Title: Re: The 2019 melting season
Post by: Aluminium on April 02, 2019, 07:14:25 AM
March 27 - April 1.
Title: Re: The 2019 melting season
Post by: Rodius on April 02, 2019, 08:08:16 AM
Is that super long crack along the Russian border weird?
Title: Re: The 2019 melting season
Post by: jdallen on April 02, 2019, 08:34:26 AM
Is that super long crack along the Russian border weird?
Nope.

It generally follows the transition from near-shore "fast" ice to ice over deeper waters, that is more subject to wind and current.
Title: Re: The 2019 melting season
Post by: Rodius on April 02, 2019, 08:42:31 AM
Is that super long crack along the Russian border weird?
Nope.

It generally follows the transition from near-shore "fast" ice to ice over deeper waters, that is more subject to wind and current.

Thanks
Title: Re: The 2019 melting season
Post by: jdallen on April 02, 2019, 08:43:46 AM
Spent a couple of hours fruitlessly tinkering with CAPIE and average thickness, trying to see if anything interesting turned up.

Mostly not, and not really worth posting charts.  The TL;DR is, the end of season thickness has remained relatively constant for most of the last 15 years, dropping slightly on average to about 1.75M.

The "start of season" average thickness has dropped pretty dramatically, now at around 3-3.5M

Neither of these unfortunately tell us much of anything except they are derivative of changes in area and volume, for which they are the ratio, and in spite of widely changing ranges of area, have stayed pretty surprisingly constant - +/- about .25M - over the last 10-15 years.

My take away is that average thickness will probably remain pretty much the same at the end of season until we blow out completely (as in sub 1,000,000KM2).  But then, oddly, the average thickness at end of season may go UP, as a higher proportion of the surviving ice may consist of stuff calving off of glaciers in the CAA and Greenland.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 02, 2019, 12:09:26 PM
A slight "rebound" in high resolution AMSR2 area, with extent flatlining for the last couple of days:

http://GreatWhiteCon.info/2019/04/facts-about-the-arctic-in-april-2019/
Title: Re: The 2019 melting season
Post by: uniquorn on April 02, 2019, 12:25:52 PM
amsr2-uhh, atlantic side, mar1-apr1.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 02, 2019, 02:01:31 PM
Yep. It was never great, but I really was not expecting that drop over a week or so.

Showing last decade. Current 2019 in orange (lowest extent for this date)
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Title: Re: The 2019 melting season
Post by: Paladiea on April 02, 2019, 02:28:33 PM
Drawing any seasonal conclusion from early season ice loss seems foolish.
On the other hand, completely ignoring early season losses on the grounds of low correlation may not be so wise, especially when said early losses take the ice into record territory. It does not necessarily mean the melting season will be exceptional, but it does increase the risk.

That is true.  On the other hand, it may just mean ice that would melt regardless has melted earlier than expected.  Baring any exceptional summer weather (a la 2012), this may just even out in the coming months (like 2002).  We shall see.

I think you're missing something important in your analysis, and that is the fact that ice isn't 2 dimensional, but 3.

Ice volume is also very important in how resistant it is to melt, and correlating extent and area to melt isn't going to hold on for much longer if it held up at all.
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 02, 2019, 03:30:19 PM
Drawing any seasonal conclusion from early season ice loss seems foolish.
On the other hand, completely ignoring early season losses on the grounds of low correlation may not be so wise, especially when said early losses take the ice into record territory. It does not necessarily mean the melting season will be exceptional, but it does increase the risk.

That is true.  On the other hand, it may just mean ice that would melt regardless has melted earlier than expected.  Baring any exceptional summer weather (a la 2012), this may just even out in the coming months (like 2002).  We shall see.

I think you're missing something important in your analysis, and that is the fact that ice isn't 2 dimensional, but 3.

Ice volume is also very important in how resistant it is to melt, and correlating extent and area to melt isn't going to hold on for much longer if it held up at all.

Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two. 
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 02, 2019, 04:12:52 PM
Uniquorn's animation of the Kara sea ice shows that Atlantic water is flowing into the Barents sea (and mixing with Siberian river water) then flowing into the Kara sea. The ice in the Kara sea looks very thin and is likely to melt out very early this year.

The distribution of thick ice is very unfortunate this early spring. The average thickness this year may be similar to what it has been for the past decade but the thick ice is piled up at the Arctic's exit doors. At the same time, warm and salty water is flowing in through the entrances. The Bering strait water has no heat content yet, but the break up of ice along the Alaskan shores of the Bering sea came several months early this year. It's possible that we could see the advection of heat in water flowing through the Bering strait this summer. This story of a man floating out to sea personalizes just how crazy this spring has been in Alaska.

https://www.adn.com/alaska-news/rural-alaska/2019/03/14/man-rescued-from-ice-drifting-in-bering-sea-describes-hours-jumping-from-floe-to-floe/



So Rode and two other Nome men, 43-year-old John Culp Jr. and 33-year-old James Gibson, went out on the ice to move the equipment. They’d dug out a skiff out of snowdrifts and were going to use it to load some of the gear in to using leads, patches of open water between sheets of ice, to ferry it back to shore.

The open water alone was bizarre, said Rode: Usually the ice off Nome is solid until early May. People crab and dredge for gold through the ice.

“We never have open water this time of year,” he said. “Usually the ice is 8 feet thick. This year it was only a couple feet thick, not even frozen very hard. It’s bizarre.”
Title: Re: The 2019 melting season
Post by: uniquorn on April 02, 2019, 04:51:11 PM
Winds have favored the influx of Atlantic and Pacific waters and the outflow of ice and fresh water through the Fram and Nares straits <snips>
I'm not sure if it's wind or ssh driven but all three of the northernmost whoi ITP buoys are moving north east against the annual ice drift. http://www.whoi.edu/page.do?pid=163456
Title: Re: The 2019 melting season
Post by: Ktb on April 02, 2019, 08:48:16 PM
Slater projection has been stalled out for past several days. 50 day lead time now just 39 days.

http://cires1.colorado.edu/~aslater/SEAICE/


I have sent their IT team a message.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 02, 2019, 09:43:42 PM
The ice in the Kara sea looks very thin and is likely to melt out very early this year.

The current merged CryoSat-2/SMOS sea ice thickness for the Northern Sea Route:

Title: Re: The 2019 melting season
Post by: epiphyte on April 02, 2019, 09:54:09 PM

Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

By that logic, a helium balloon, a pressure cooker, and a nuclear reactor containment vessel are all essentially similar, so they must be functionally interchangeable.
Title: Re: The 2019 melting season
Post by: Pavel on April 02, 2019, 11:27:26 PM
The warm anomalies have extended to the north of 80 latitude but it still very far from melting in the high Arctic
Title: Re: The 2019 melting season
Post by: Juan C. García on April 02, 2019, 11:45:38 PM
Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

If this third dimension "is several orders of magnitude smaller than the other two", could be the first one in disappearing. But if this dimension disappears: ¿what will happen to the other two?
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 02, 2019, 11:52:16 PM
Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

If this third dimension "is several orders of magnitude smaller than the other two", could be the first one in disappearing. But if this dimension disappears: ¿what will happen to the other two?

Funny, but irrelevant to the discussion at hand.
Title: Re: The 2019 melting season
Post by: Viggy on April 03, 2019, 12:11:32 AM
Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

If this third dimension "is several orders of magnitude smaller than the other two", could be the first one in disappearing. But if this dimension disappears: ¿what will happen to the other two?

Funny, but irrelevant to the discussion at hand.

Why would the 3rd dimension in a 3 dimensional product (i.e. sea ice) be irrelevant?

Doesn't extent only go to 0 when that 3rd dimension goes to 0?
Title: Re: The 2019 melting season
Post by: uniquorn on April 03, 2019, 12:40:41 AM
Update on utqiagvik as seen by ascat. Chukchi sea and the Alaskan coast having quite a hard time of it.
ascat feb15-apr1, 7days/sec
edit:day labelling corrected
Title: Re: The 2019 melting season
Post by: epiphyte on April 03, 2019, 02:59:18 AM
Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

If this third dimension "is several orders of magnitude smaller than the other two", could be the first one in disappearing. But if this dimension disappears: ¿what will happen to the other two?

Funny, but irrelevant to the discussion at hand.

Why would the 3rd dimension in a 3 dimensional product (i.e. sea ice) be irrelevant?

Doesn't extent only go to 0 when that 3rd dimension goes to 0?

Quite. The area can only even be _defined_ in terms of the question, "where is the thickness not zero?"

...which ironically makes the 3rd dimension the _only_ one that's relevant.

 
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 03, 2019, 03:16:51 AM
Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

If this third dimension "is several orders of magnitude smaller than the other two", could be the first one in disappearing. But if this dimension disappears: ¿what will happen to the other two?

Funny, but irrelevant to the discussion at hand.

Why would the 3rd dimension in a 3 dimensional product (i.e. sea ice) be irrelevant?

Doesn't extent only go to 0 when that 3rd dimension goes to 0?

Conversely, the third dimension cannot go to 0, without the extent going to 0.  The extent will change based on the dimension which has the greatest influence.  The factors influencing thickness, like wave action, are small compared to those acting on the overall area, sunlight and seawater.  Thickness changes does not drive the sea ice, rather they occur through these other factors.
Title: Re: The 2019 melting season
Post by: Archimid on April 03, 2019, 03:59:24 AM
The factors influencing thickness, like wave action, are small compared to those acting on the overall area, sunlight and seawater.  Thickness changes does not drive the sea ice, rather they occur through these other factors.

Processes controlling surface, bottom and lateral melt of Arctic sea ice in a state of the art sea ice model

https://www.researchgate.net/publication/281622252_Processes_controlling_surface_bottom_and_lateral_melt_of_Arctic_sea_ice_in_a_state_of_the_art_sea_ice_model

Relevant graph from the article attached.

Title: Re: The 2019 melting season
Post by: Klondike Kat on April 03, 2019, 04:27:40 AM
The factors influencing thickness, like wave action, are small compared to those acting on the overall area, sunlight and seawater.  Thickness changes does not drive the sea ice, rather they occur through these other factors.

Processes controlling surface, bottom and lateral melt of Arctic sea ice in a state of the art sea ice model

https://www.researchgate.net/publication/281622252_Processes_controlling_surface_bottom_and_lateral_melt_of_Arctic_sea_ice_in_a_state_of_the_art_sea_ice_model

Relevant graph from the article attached.

Thank you Archimid.  From the article, “Decompising the total ice melt shows that bottom melt accounts for more than two-thirds of the total melt, top melt accounts for almost a third of the total, and lateral melt contributes less than 10%.”
Title: Re: The 2019 melting season
Post by: oren on April 03, 2019, 05:33:49 AM
I found KK's original comment on the irrelevance of volume/thickness to be quite opposite to reality, but decided to avoid cluttering this thread. I am sure many feel the same. I'd appreciate it if anybody can point to a relevant thread where this can be discussed freely.
Title: Re: The 2019 melting season
Post by: Sterks on April 03, 2019, 09:34:11 AM
Yeah I agree with Oren.
And the sheer dumbness or even mendacity of KK arguments makes it off topic.
And I won't elaborate on why they are dumb (review six years of forum or post in Stupid Questions. Well not even. ) And I won't respond to KK
Title: Re: The 2019 melting season
Post by: Neven on April 03, 2019, 09:38:30 AM
Let's be nice, this isn't the Trump-thread.
Title: Re: The 2019 melting season
Post by: epiphyte on April 03, 2019, 09:58:39 AM
Let's be nice, this isn't the Trump-thread.

I live in Minnesota, so nice pretty much goes with the territory.

I do have to say that I find it hard to believe that KK is for real though. How nice must one be in the face of unashamed trollery? (or is that trollericiousness? - my spell-checker is failing me on this point.)

Title: Re: The 2019 melting season
Post by: Jim Hunt on April 03, 2019, 01:27:01 PM
I do have to say that I find it hard to believe that KK is for real though.

Here you go:

"Are 3 dimensions better than 2 (https://forum.arctic-sea-ice.net/index.php/topic,2618.0.html)?"

Quote
A place to be nice whilst debating volume/thickness versus area/extent whilst not cluttering up the 2019 melting season thread.
Title: Re: The 2019 melting season
Post by: magnamentis on April 03, 2019, 01:46:08 PM
The warm anomalies have extended to the north of 80 latitude but it still very far from melting in the high Arctic

far from melting but impacts peak thickness and volume, which, depending on summer weather can make a huge difference in the final outcome of this melting season
Title: Re: The 2019 melting season
Post by: magnamentis on April 03, 2019, 01:48:45 PM
Funny, but irrelevant to the discussion at hand.

declaration of irrelevance is the only way to avoid admitting a "faux pas"

hope it's nice enough, at least the nicest way to answer the question "why....."
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 03, 2019, 01:51:47 PM
Since we seem to getting back to referencing the science at long last, here's a recent paper by Stefan Hendricks of this parish et al.:

"Arctic warming interrupts the Transpolar Drift and affects long-range transport of sea ice and ice-rafted matter (https://www.nature.com/articles/s41598-019-41456-y)"

Quote
Due to the recently observed acceleration in sea ice drift, it has been assumed that more matter is advected by the transpolar Drift from shallow shelf waters to the central Arctic ocean and beyond. However, this study provides first evidence that intensified melt in the marginal zones of the Arctic ocean interrupts the transarctic conveyor belt and has led to a reduction of the survival rates of sea ice exported from the shallow Siberian shelves (−15% per decade). As a consequence, less and less ice formed in shallow water areas (<30 m) has reached Fram Strait (−17% per decade), and more ice and ice-rafted material is released in the northern Laptev Sea and central Arctic Ocean.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 03, 2019, 01:53:51 PM
declaration of irrelevance is the only way to avoid admitting a "faux pas"

Perhaps I spoke too soon? At the risk of repeating myself - Here you go:

"Are 3 dimensions better than 2? (https://forum.arctic-sea-ice.net/index.php/topic,2618.0.html)"
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 03, 2019, 02:08:18 PM
Funny how one comment can be misconstrued and amplified to mean something else altogether.  For the record, I never said that either thickness or volume was irrelevant - that was Oren.  I was referring to epiphyte's comment about one dimension going to zero, and being the only one that is relevant.  Obviously, one dimension of a three-dimensional object cannot go to zero, without the other dimensions following simultaneously (this is not abstract math).  Consequently, it is not relevant to this thread to talk about one dimension going to zero, while the others do not.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 03, 2019, 02:09:26 PM
Funny how one comment can be misconstrued

At the risk of repeating myself repeating myself - Here you go:

"Are 3 dimensions better than 2 (https://forum.arctic-sea-ice.net/index.php/topic,2618.0.html)?"
Title: Re: The 2019 melting season
Post by: Davidsf on April 03, 2019, 03:48:13 PM
Jim thanks for posting the article on transpolar drift, but when I followed the link, the text of article was broken up and unreadable. Advice welcome.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 03, 2019, 03:57:29 PM
When I followed the link, the text of article was broken up and unreadable. Advice welcome.

It looks fine to me in Opera on Windows 10. Can you not even try to download the PDF and examine it in Acrobat or similar?
Title: Re: The 2019 melting season
Post by: LRC1962 on April 03, 2019, 04:04:54 PM
Jim thanks for posting the article on transpolar drift, but when I followed the link, the text of article was broken up and unreadable. Advice welcome.
another readable link can be found here: https://www.nature.com/articles/s41598-019-41456-y (sharing link points to an epdf file that is not working)
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 03, 2019, 05:38:27 PM
Another readable link can be found here

Thanks LRC. I've modified the link in my original post. Another brief extract from the paper:

Quote
Sea ice thickness measurements from the AWI IceBird program are available via the project’s homepage:

https://www.awi.de/en/science/climate-sciences/sea-ice-physics/projects/ice-bird.html.

Results from the tracking experiments were uploaded to PANGAEA and will be available soon. The gridded thickness fields from the radar altimeters onboard the Envisat and CryoSat-2 satellite platforms are available at the CCI Data Portal.

Does anyone know if "the CCI Data Portal" is open to the average "citizen scientist" in the street? In the meantime I'm happily using the gridded thickness fields available via the "FMI Data Portal" at:

http://ice.fmi.fi/data/arctic/cs2-smos-nrt-sea-ice-thickness/

Title: Re: The 2019 melting season
Post by: shendric on April 03, 2019, 06:16:57 PM
Quote
Does anyone know if "the CCI Data Portal" is open to the average "citizen scientist" in the street?

All CCI data (and ESA data for this matter) is open and public:

ftp://anon-ftp.ceda.ac.uk/neodc/esacci/sea_ice/data/sea_ice_thickness/
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 04, 2019, 03:08:00 AM
Let's be nice, this isn't the Trump-thread.

He won, the dirty orange goblin. It is a Trump world now. ASIF isn't immune.


I think the ice looks good. Thick, old, and stable. I'm not worried.   ;)
Title: Re: The 2019 melting season
Post by: Paladiea on April 04, 2019, 08:04:43 AM
I think you're missing something important in your analysis, and that is the fact that ice isn't 2 dimensional, but 3.

Ice volume is also very important in how resistant it is to melt, and correlating extent and area to melt isn't going to hold on for much longer if it held up at all.

Yes, but that third dimension, thickness, is several orders of magnitude smaller than the other two.  Hence, the third dimension forces have much less influence on the total makeup than the other two.

I think you misunderstand me, the issue isn't that you should take all three separately, but that you should use volume, or perhaps even better, density.


Quote
Conversely, the third dimension cannot go to 0, without the extent going to 0.  The extent will change based on the dimension which has the greatest influence.  The factors influencing thickness, like wave action, are small compared to those acting on the overall area, sunlight and seawater.  Thickness changes does not drive the sea ice, rather they occur through these other factors.


While technically this might be true, the volume of sea ice can tell us a lot about how resistant it is to melting. Thick compact multiyear ice is much fresher (has less salt), much colder, and generally more resistant to melting than say slush even though they might cover the same area.

And the reason I suggested 'density' was because volume only gives the total 3d space the ice occupies, not how solid the ice is in that 3d space. Using the example I said above, everyone would agree that said thick multiyear ice is far more resistant than first year ice that might have the same volume.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 04, 2019, 08:14:11 AM
density

Boy, oh boy. Yet another dimension.  ;D

Paladiea, can you or someone briefly elaborate on how density would influence melting, please.
Title: Re: The 2019 melting season
Post by: Paladiea on April 04, 2019, 08:15:49 AM
density

Boy, oh boy. Yet another dimension.  ;D

Paladiea, can you or someone briefly elaborate on how density would influence melting, please.


I've edited my above reply to reflect your question.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 04, 2019, 08:43:59 AM
I've edited my above reply to reflect your question.

Thank you! Makes sense to me now. :)
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 04, 2019, 09:35:07 AM
All CCI data (and ESA data for this matter) is open and public:

Thanks very much Stefan. At first glance the new FMI merged thickness product is easier to use than the CCI data you linked to. Does the FMI product suffer from any significant disadvantages?
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 04, 2019, 09:36:15 AM
Paladiea, can you or someone briefly elaborate on how density would influence melting, please.

(Repeating myself)^n

https://forum.arctic-sea-ice.net/index.php/topic,2618.0.html
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 04, 2019, 09:37:35 AM
There's no sign of a significant slowdown in early season melt just yet:
Title: Re: The 2019 melting season
Post by: shendric on April 04, 2019, 03:23:46 PM
All CCI data (and ESA data for this matter) is open and public:

Thanks very much Stefan. At first glance the new FMI merged thickness product is easier to use than the CCI data you linked to. Does the FMI product suffer from any significant disadvantages?

Hi Jim,

what do you mean with "easier"? The file format (netCDF) is the same.

The biggest difference between the CCI climate data record and the FMI/AWI CryoSat-2/SMOS (CS2SMOS) data is that the CCI objective is on consistency over longer periods. There was no SMOS-like data back in 2002, so the CCI uses radar altimetry from Envisat and CryoSat-2 only. Also, there is no interpolation or gap-filling to be as close to the actual observation as possible. Thats why the CCI data set as both the track data (L2P: Level-2 pre-processed) and the gridded maps (L3C: Level-3 collated).

The CS2SMOS product however uses interpolation as an integral part of the CryoSat-2/SMOS data merging and thus is much smoother than the actual observations of either satellite. The CryoSat-2 contribution to CS2SMOS is quite similar to the CryoSat-2 part in the CCI data record.

Cheers, Stefan
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 04, 2019, 05:04:38 PM
-6˚ to 0˚C over Beaufort and Chukchi forecasted by GFS.

http://www.wetterzentrale.de/en/topkarten.php?map=2&model=gfs&var=5&run=0&time=240&lid=OP&h=0&mv=0&tr=24#mapref
Title: Re: The 2019 melting season
Post by: El Cid on April 04, 2019, 07:03:59 PM
-6˚ to 0˚C over Beaufort and Chukchi forecasted by GFS.


It's not there on the latest run and it is not there on ECMWF. Besides, anything beyond 5 days is always suspect.
ECMWF has bering/chukchi, and generally the whole arctic very warm the next 3 days, and then Greenland is very warm, but gets cooler at other places
Title: Re: The 2019 melting season
Post by: jdallen on April 04, 2019, 09:09:50 PM
-6˚ to 0˚C over Beaufort and Chukchi forecasted by GFS.


It's not there on the latest run and it is not there on ECMWF. Besides, anything beyond 5 days is always suspect.
ECMWF has bering/chukchi, and generally the whole arctic very warm the next 3 days, and then Greenland is very warm, but gets cooler at other places
Agree, but it does indicate a trend.  While the specific regions affected haven't necessarily followed the 5+ day forecasts, the intrusions of heat and moisture have tended to follow.

Cold over the thickest ice (which is what appears to be indicated) won't help as much as if it happened over areas forecast to be torched. If the heat does continue to surge on the pacific side we could we early disintegration of both the Chukchi and outer Beaufort.  Early increases in heat uptake could be as bad or worse than melt ponds.  Ill be watching what Tealights tools show us.
Title: Re: The 2019 melting season
Post by: El Cid on April 04, 2019, 09:24:50 PM
And I agree with you :)

Pacification is the new trend after Atlantification. The Bering and Chukci will likely "evaporate" pretty fast.

 If the Atlantic side keeps playing the role  of the killzone, and the Pacific side gets wiped out early, then this year we could really see amazing records.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 04, 2019, 09:26:47 PM
-6˚ to 0˚C over Beaufort and Chukchi forecasted by GFS.


It's not there on the latest run and it is not there on ECMWF. Besides, anything beyond 5 days is always suspect.
ECMWF has bering/chukchi, and generally the whole arctic very warm the next 3 days, and then Greenland is very warm, but gets cooler at other places
Agree, but it does indicate a trend.  While the specific regions affected haven't necessarily followed the 5+ day forecasts, the intrusions of heat and moisture have tended to follow.

Cold over the thickest ice (which is what appears to be indicated) won't help as much as if it happened over areas forecast to be torched. If the heat does continue to surge on the pacific side we could we early disintegration of both the Chukchi and outer Beaufort.  Early increases in heat uptake could be as bad or worse than melt ponds.  Ill be watching what Tealights tools show us.
I think this year is a perfect storm of both early heat uptake AND melt ponds. There are probably large melt ponds already forming across most of the Beaufort. I think this very early 1-2 punch will be sufficient to melt out the Beaufort entirely this year, which will be unlike most recent years, although this is also due to the lack of any substantial areas of thick ice this year as well. The same goes for ESS and Chukchi although both of those have been melting out most completely with more consistency than Beaufort.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 04, 2019, 09:30:39 PM
PS, here is March 2019 minus 2012. I guess this is what -1M KM^2 of extent in seven years looks like. It certainly appears we may have a running leap leading into the melt season this year.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 04, 2019, 10:46:57 PM
What do you mean with "easier"? The file format (netCDF) is the same.

I wasn't referring to the file format. Obviously FMI is "easier" for NRT updates on threads like this one, and CCI's "easier" for historical comparisons!

Compare and contrast the two images below. SMOS fills in some gaps around the edges in the FMI based image, and the interpolation you refer to is visually evident. That makes the FMI image easier on the eye (IMHO), and thanks for explaining what gets lost during the processing.
Title: Re: The 2019 melting season
Post by: uniquorn on April 05, 2019, 12:01:36 AM
I think this year is a perfect storm of both early heat uptake AND melt ponds. There are probably large melt ponds already forming across most of the Beaufort.
While I tend to agree with the first part, I would say that melt ponds in the beaufort are working towards investigating the processes involved in the possibility of forming. ;)

Some 'on the ice' temperatures in and around the beaufort are available from the whoi ITP buoys (ITP103-110) released late sep-oct. Also shown is ITP89, released in 2015 and currently lodged in the CAA, which gives an idea at what point from recent years we might expect melt ponds to activate the above intention.
http://www.whoi.edu/page.do?pid=163197

edit: the recent warm spell can be seen after day450 on last years buoys
 
Title: Re: The 2019 melting season
Post by: jdallen on April 05, 2019, 02:40:41 AM
I think this year is a perfect storm of both early heat uptake AND melt ponds. There are probably large melt ponds already forming across most of the Beaufort.
While I tend to agree with the first part, I would say that melt ponds in the beaufort are working towards investigating the processes involved in the possibility of forming. ;)
<Laughter>
I concur.  April melt ponds, no.  May meltponds, a distinct and unpleasant possibility.

Also in play - increased and earlier snow melt outflow from peri-arctic drainages, which I think may further accelerate the melt.  Anyone have eyeballs on what the Mackenzie is doing currently, for example?
Title: Re: The 2019 melting season
Post by: bbr2314 on April 05, 2019, 05:54:35 AM
JAXA -70K. 2016's final descent below our current number occurred on 4/16 that year (a record for the date). If we follow 2010s averages we will maintain the record quite easily through early May, and in a month we should be below 12M KM^2 (avg loss of 1.2M KM^2 through 5/5).
Title: Re: The 2019 melting season
Post by: Aluminium on April 05, 2019, 08:12:45 AM
March 30 - April 4.

Ice has broken in upper Ob and Yenisei rivers. Slightly earlier than usual.
Title: Re: The 2019 melting season
Post by: oren on April 05, 2019, 08:35:26 AM
March 30 - April 4.
Thanks a lot for these periodic animations.
It looks like continued two-sided wind movement/ice compaction/melting: From the Pacific through the Bering Strait and into the Chukchi, and from the Atlantic into the Kara Sea. At the same time, ice is being exported in mass from the CAB via the Fram into the Greenland Sea and via the FJL-Svalbard gap into the Barents. Such a persistent overall movement is really bad at the start of the melting season, and the more it continues the more damage is incurred.
Should the winds reverse Chukchi and Kara can regrow to their max level, but the thick exported ice will not come back from the Atlantic kill zone.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 05, 2019, 09:00:37 AM
I know I was made fun of re: melt ponds a few posts back but a look at the graphic from Aluminum shows that there has indeed been widespread sporadic melt ponding over much of the Arctic (IMO). It may not be incredibly consistent but even temps of -5C, when combined with increasing sun angle, can yield melting snowpack and growing melt ponds. As anyone who has been outside on a sub-32F spring day in can attest, bright sunshine can more than overwhelm marginally cold temps to result in melt.

I think this pre-conditioning is setting the stage for an epic collapse of the Beaufort, ESS, and Chukchi come May->June. Kara also looks to be in staunch retreat already although I guess regrowth is still possible there.
Title: Re: The 2019 melting season
Post by: binntho on April 05, 2019, 09:35:37 AM
I know I was made fun of re: melt ponds a few posts back but a look at the graphic from Aluminum shows that there has indeed been widespread sporadic melt ponding over much of the Arctic (IMO).

So a "look" at Aluminiums graphic "shows" melt ponding - whatever that means. Perhaps it's possible to convince yourself that the black smudges are "widespread sporadic melt ponding". Or not. Sometimes it's better to stop digging.
Title: Re: The 2019 melting season
Post by: JayW on April 05, 2019, 10:09:59 AM
The nice folks over at the RAMMB CIRA site from Colorado State University have added Suomi and N20 imagery to their slider at 51 minute intervals.  Perhaps some will find this of interest.
Here's the last 2 days focused on the Kara Sea.  There are additional bands available, along with the ability to overlay and zoom.  Unfortunately, it can't be rotated in the slider.

http://rammb-slider.cira.colostate.edu/?sat=jpss&z=2&im=54&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=1&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=1&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=northern_hemisphere&p%5B0%5D=band_m07&x=13379&y=12292
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 05, 2019, 10:22:29 AM


That's truly amazing! Thank you for that link.
Title: Re: The 2019 melting season
Post by: johnm33 on April 05, 2019, 11:31:21 AM
"melt ponds" Looks more like weak 2 dimensional ice being pushed around by winds/currents as much opening as there is compaction followed by rapid surface freezing.
"I think this pre-conditioning is setting the stage for an epic collapse of the Beaufort, ESS, and Chukchi come May->June. Kara also looks to be in staunch retreat already although I guess regrowth is still possible there. " I agree.
Title: Re: The 2019 melting season
Post by: IceConcerned on April 05, 2019, 11:52:08 AM
When looking at Aluminium animation, I am marked by the appearnce of big, long cracks within the ice. The wind force and derive must be very strong :
This time they appear mainly off the north Siberian coast, but there is a small one in Beaufirt too. And I remember seeing them on other previous animation too : do I have bad memories, or is it indeed a first ?
Title: Re: The 2019 melting season
Post by: be cause on April 05, 2019, 12:21:26 PM
When looking at Aluminium animation, I am marked by the appearnce of big, long cracks within the ice. The wind force and derive must be very strong :
This time they appear mainly off the north Siberian coast, but there is a small one in Beaufirt too. And I remember seeing them on other previous animation too : do I have bad memories, or is it indeed a first ?

this is the norm .. or at least the new norm when winds are blowing off-shore . Last year it was an almost continuous process. New ice will form in the cracks and contribute to volume .. and the cracks allow heat to escape .  b.c.
Title: Re: The 2019 melting season
Post by: uniquorn on April 05, 2019, 01:51:11 PM
Fast ice in ess looking a bit weaker than last year.
Worldview, terra modis, apr5 2018 and 2019.

@bbr, agreed on preconditioning but not about melt ponds. Please check clouds over the beaufort on worldview vs amsr2.
edit: thanks JayW
Title: Re: The 2019 melting season
Post by: Neven on April 05, 2019, 02:33:58 PM
Melt onset usually occurs under clouds. The snow then refreezes, but its structure has changed, making it easier for melt ponds to form some time later.
Title: Re: The 2019 melting season
Post by: oren on April 05, 2019, 02:42:45 PM
I think the date and the weather is still too early for melt ponds and other snow structure effects.
OTOH the Kara ice in JayW's animation looks pretty bad.
Title: Re: The 2019 melting season
Post by: uniquorn on April 05, 2019, 06:12:33 PM
Melt onset usually occurs under clouds. The snow then refreezes, but its structure has changed, making it easier for melt ponds to form some time later.
Apologies to all then, especially bbr.
Title: Re: The 2019 melting season
Post by: Neven on April 05, 2019, 06:26:27 PM
No need to apologize, you were right that it's too early for melt pond formation. There may be some melt onset here and there, and this may have an effect in a couple of weeks on melt pond formation. You could call it pre-preconditioning.  ;)

But melt onset usually occurs earlier under cloudy conditions.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 05, 2019, 07:27:03 PM
A slight "rebound" in high resolution AMSR2 area, with extent flatlining for the last couple of days:
Yes. One more day of the same angle of descent on NSIDC graph right now would have been be pretty concerning. It can still crawl back among the crowd and stay there (among the lowest crowd on record that is).
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 05, 2019, 07:31:13 PM
No need to apologize, you were right that it's too early for melt pond formation. There may be some melt onset here and there, and this may have an effect in a couple of weeks on melt pond formation. You could call it pre-preconditioning.  ;)
But melt onset usually occurs earlier under cloudy conditions.
Unless it has been raining on the Arctic sea-ice as well. Unlikely, but I don't discount any wierd development these days.
https://www.bbc.com/news/science-environment-47485847
Title: Re: The 2019 melting season
Post by: Sterks on April 05, 2019, 09:23:24 PM
I share a certain gloomy feeling about this year compared to what happened in the past two seasons
* NH temp anomalies back to record territory
* A distinct ring of negative snow cover anomaly is forming all around the NH including US and Canada where abundant winter snowfall is now melting quickly. Google rutgers ice lab (sorry getting too old to download resize and crop as needed). This signals early Spring, generalized, did not happen since 2016.
* Oceanic anomalous heat input since beginning of year is apparent esp. thru Bering.
* Record low extent may not be determinant, but sure won’t help
* The preconditioning in Kara and Chukchi may be real, will refreeze but again, won’t help
* The thickest ice is again tilted against the Atlantic
Anything can happen but I have a bad feeling that I didn’t have since 2015. Ok I thought that was it in 2017 too, but fell again in the trap of “low thickness will trump weather”. Weather trumps all.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on April 05, 2019, 09:59:17 PM
Quote
Weather trumps all.
Especially blow-it-out-into-the-Atlantic weather!
Title: Re: The 2019 melting season
Post by: magnamentis on April 06, 2019, 01:44:44 AM
I share a certain gloomy feeling about this year compared to what happened in the past two seasons
* NH temp anomalies back to record territory
* A distinct ring of negative snow cover anomaly is forming all around the NH including US and Canada where abundant winter snowfall is now melting quickly. Google rutgers ice lab (sorry getting too old to download resize and crop as needed). This signals early Spring, generalized, did not happen since 2016.
* Oceanic anomalous heat input since beginning of year is apparent esp. thru Bering.
* Record low extent may not be determinant, but sure won’t help
* The preconditioning in Kara and Chukchi may be real, will refreeze but again, won’t help
* The thickest ice is again tilted against the Atlantic
Anything can happen but I have a bad feeling that I didn’t have since 2015. Ok I thought that was it in 2017 too, but fell again in the trap of “low thickness will trump weather”. Weather trumps all.

+1
Title: Re: The 2019 melting season
Post by: El Cid on April 06, 2019, 09:11:26 AM
The biggest change this spring is that the Bering is wide open. No other year - except for 2018 - had this pattern (see comparison with 2016 attached). Every other year, we had much more ice in the Bering Sea. It seems that Pacification is really happening right now, in front of our eyes.
Besides, it is going to be quite warm in the Bering-Chukchi area the next week or so. A strong attack from the Pacific side seems likely this summer
Title: Re: The 2019 melting season
Post by: Gray-Wolf on April 06, 2019, 10:01:37 AM
It seems that Pacification is really happening right now, in front of our eyes.


I think we know that Nino events can , via Kelvin waves, push warm surface waters up the U.S. coast and into the basin via Bering?

Now we are in a low grade nino event but no big Kelvin waves have really had impact but we should remember the state of the Interdecadal Pacific oscillation since 2014?

Since 2014 this natural forcing has been in its positive state. This means that, over its area of influence , warmed surface waters are present ( instead of being buried in the upper ocean?) .Will this mean twenty odd years of ever warmer surface waters pushing in from the Pacific side of the basin?

It's early days but maybe we have left it long enough to expect more melt over the Pacific side as Pacific ocean currents begin to deliver these warmed surface waters ?
Title: Re: The 2019 melting season
Post by: epiphyte on April 06, 2019, 10:30:42 AM
The biggest change this spring is that the Bering is wide open.

Biggest change to the ice, yes... but also look at Alaska from Beaufort to the Pacific over the past 10 days. For my money, the last time it was that green was 2011 - which was the crappiest year ever for Beaufort+CAA.
Title: Re: The 2019 melting season
Post by: sark on April 06, 2019, 11:02:48 AM
the cold of the polar cell doesn't sit still any more, not content to simply reach out long wings of air outbreaks.  now it's closer to chaos.  I say "now" as November 2016 and Now being primary examples of complete and total breakdown of the polar cell.

It's only been wildly unstable for 20 years.  Something's gotta give.
Title: Re: The 2019 melting season
Post by: El Cid on April 06, 2019, 12:19:35 PM
November 2016 and Now being primary examples of complete and total breakdown of the polar cell.


Where do we see a " complete and total breakdown" of the polar cell?
Title: Re: The 2019 melting season
Post by: uniquorn on April 06, 2019, 04:32:01 PM
umi-bremen smos, apr5 2011-2019.
mercator(model) salinity 0m, mar1-apr5.
Title: Re: The 2019 melting season
Post by: pauldry600 on April 06, 2019, 05:26:22 PM
Think melt will slow this coming week and 2nd place will be "only" 100k away again.

Still time for a further slowdown and melt to finish in top 5 at end instead of this rather false position its in now
Title: Re: The 2019 melting season
Post by: Jacobus on April 06, 2019, 06:19:43 PM
November 2016 and Now being primary examples of complete and total breakdown of the polar cell.


Where do we see a " complete and total breakdown" of the polar cell?
Good question. Based purely on observation I'd say the breakdown has been in progress for some time, but is not yet complete and total. The polar cell is severely weakened and on its way out in the coming years, but still alive for now.
Title: Re: The 2019 melting season
Post by: Shared Humanity on April 06, 2019, 06:58:54 PM
Actually, the position it is in is exactly the position it is in. Useful to try to understand the processes that cause it to be in this position.
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 06, 2019, 07:45:59 PM
The unprecedented drop in sea ice extent, area and volume for late March and the first week of April is the result of unprecedented warm air advection from the Pacific and Atlantic ocean regions into the Arctic. It is as real as hitting your thumb with a hammer.

Maybe the weather will cool off and the melting will slow down, but reality is that Alaska just had the warmest March on record and the past 2 years have had record low amounts of ice in the Bering sea in March and early April. This is reality.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 07, 2019, 05:32:19 AM
JAXA -90K. At 13.01M KM^2. Woof.
Title: Re: The 2019 melting season
Post by: wdmn on April 07, 2019, 06:12:53 AM
JAXA -90K. At 13.01M KM^2. Woof.

Your numbers don't match what Juan just posted.
Title: Re: The 2019 melting season
Post by: Pmt111500 on April 07, 2019, 06:17:34 AM
The unprecedented drop in sea ice extent, area and volume for late March and the first week of April is the result of unprecedented warm air advection from the Pacific and Atlantic ocean regions into the Arctic. It is as real as hitting your thumb with a hammer.

Maybe the weather will cool off and the melting will slow down, but reality is that Alaska just had the warmest March on record and the past 2 years have had record low amounts of ice in the Bering sea in March and early April. This is reality.

Long ago (2005?) tried to find annual patterns of ice melt from the charts available by then. This of course was pretty much an impossible task due ENSO, which throws off much of currents of the North Pacific. Nevertheless, taking ENSO-phase in account, there might have been some. Now that the current system has likely changed somewhat, there's also more data so someone might try to find speedy localized melting periods (or flash freezing) connected to ENSO phase. But of course, summer (and autumn, and winter partly) Arctic atmosphere has changed too from those early days so the patterns I dreamt of seeing might not be there. 3 occurrences do not a theory make, though might apply for a hypothese. The ENSO dependent patterns of ice melt might also occur on Antarctic side of things, though ACC, reaching very deep, probably prevents that.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 07, 2019, 06:58:08 AM
JAXA -90K. At 13.01M KM^2. Woof.

Your numbers don't match what Juan just posted.
Oops. Was -78K. Mis-math'd. Still bad! We should clear 13M KM^2 tomorrow.
Title: Re: The 2019 melting season
Post by: Neven on April 07, 2019, 10:11:26 AM
The pace of JAXA SIE drops is quite stunning, given that it's already so low. And it might continue to stun, as the current forecast points quite simply to a dipole that may cause open water along the Beaufort coasts, and things aren't looking all that great for the ice in the Kara either.

Last year we had a similar situation around this time, and I'll repeat what I said back then (https://forum.arctic-sea-ice.net/index.php/topic,2278.msg148492.html#msg148492): The Arctic is extremely lucky it isn't mid-May yet.

Here's the forecast for the coming days, the high pressure isn't as high as last year, but the direction of the isobars (towards the Atlantic) is much more pronounced:
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 07, 2019, 11:09:46 AM
Wipneus' UH high resolution extent fell 129k:
Title: Re: The 2019 melting season
Post by: uniquorn on April 07, 2019, 12:09:42 PM
Sea of Okhotsk drop is almost vertical.

Update on Laptev, refreeze just about keeping up with the mobile ice. More southerlies are forecast, cool though.
For comparison, worldview, laptev apr7, 2010-2019
Title: Re: The 2019 melting season
Post by: uniquorn on April 07, 2019, 01:29:53 PM
Laptev mar31-apr7
Title: Re: The 2019 melting season
Post by: uniquorn on April 07, 2019, 02:27:37 PM
CAA end of the Beaufort stringer nudges back to a more normal southerly position opening up multiple fractures further north.
Thickest ice next to CAA briefly lifts off opening a temporary fracture northwards.
Nares still open. Fram export strong.
CAB to Barentsz export fairly neutral.
Kara mostly exporting to Barentsz rather than CAB.
Old Laptev ice drifts westwards past SZ.
Old CAB ice edge drifts ever nearer to the pole.
ESS tendril stretched further.
Chukchi battles with the Pacific

ascat day57-96(heavy contrast)

Title: Re: The 2019 melting season
Post by: Jim Hunt on April 07, 2019, 05:45:13 PM
A close up look at the FMI merged Cryosat-2/SMOS thickness for both the Atlantic and Pacific sides of the Arctic:

http://GreatWhiteCon.info/2019/04/facts-about-the-arctic-in-april-2019/#Apr-07

Quote
Apart from the usual thick ice queueing for the Fram Strait exit there’s not a lot to prevent the comparatively swift early melt from continuing apace.
Title: Re: The 2019 melting season
Post by: Gray-Wolf on April 07, 2019, 06:31:55 PM
I can't help but see the losses via fram/nares in human terms.

When Nares is bridged then Fram looks like vomiting.

When fram is open it is a gent taking a seat in the little room......

Either way there is far too much goodness leaching from the basin!
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 07, 2019, 07:38:59 PM
ascat day 96(heavy contrast)

I wonder how long the thicker ice in the Beaufort will hold out/rotate and the ESS arm, come late summer ?

Looking at that last ascat image, probably best you could hope for, by September, is the extent line holding at this magenta line. I expect a big bite will emerge over the Laptev and as usual the ESS arm will be attacked from Pacific intrusion and from the Laptev side.

Title: Re: The 2019 melting season
Post by: FishOutofWater on April 07, 2019, 08:10:56 PM
The open Nares strait is preventing the build up of thick ice on NW Greenland and the NE CAA. The impact is subtle but important later in the year. This situation is helping thick ice exit the Arctic.
Title: Re: The 2019 melting season
Post by: Stephan on April 07, 2019, 08:41:55 PM
I thank uniquorn for this amazing sequence.
For my understanding there is too much ice leaving the CAB through Fram and Nares. Has it been that active the last years? Maybe I can't recall correctly, but it looks like 'much more' than before which is not good...
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 07, 2019, 08:57:40 PM
This looks very broken up, more than usual?
Title: Re: The 2019 melting season
Post by: Pmt111500 on April 07, 2019, 09:19:37 PM
This looks very broken up, more than usual?
For random visitors, this is the familiar North Shore of Greenland, the rounded fractures are on the Nares strait entrance, the webbed mesh of old ice is moving towards Fram strait.

I've certainly seen both this broken up but not sure if it was April. Perhaps on May. Betting the Bering strait is getting some strong currents northwards.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 07, 2019, 10:10:52 PM
Sorry, should have said where it was. Thanks.
Title: Re: The 2019 melting season
Post by: uniquorn on April 07, 2019, 10:45:53 PM
ascat day 96(heavy contrast)
I wonder how long the thicker ice in the Beaufort will hold out/rotate and the ESS arm, come late summer ?
Hopefully the magenta line will hold, but I doubt it. Last melting season was cloudy and the Beaufort string had a higher percentage of MYI than this year (imo). Some of it may have survived in the 'slush that wouldn't melt'. Ascat is good for tracking but not necessarily a good indicator of ice thickness.
image1: The best recent viirs brightness temperature image of the stringer I could find is apr4 (https://go.nasa.gov/2FVzQtj) Darker is colder and almost certainly thicker. Alaskan coast on left. It is already recently fractured and the slightly older 'glue ice' is clearly visible.
image2: A selection of thickness products. The stringer doesn't feature heavily in any of them and the ess arm looks like it will become isolated.
Based on recent drift it's also likely that the older laptev ice will be consumed by the warm current close to FJL while the older CAB ice may just about keep the pole frozen.

Long live the magenta line :)
Title: Re: The 2019 melting season
Post by: bbr2314 on April 07, 2019, 11:15:02 PM
I have fixed the September 2019 map for everyone. I think all the FYI beyond the red line is incredibly thin this year and will be prone to severe melt ponding and very early melt-out. Wave action will take care of the MYI tendrils that remain. I know some / everyone disagrees but I think we are already seeing melt ponding begin to percolate through most areas beyond the red line thanks to recent weather.

It should be noted that North American snowcover is now rebounding slightly while Eurasia continues to plunge. North America should follow again by May but I think the Eurasian plunge will be sustained through that point (as is climo, but possibly worse than climo). We've been watching the Bering plunge year after year but it looks like this could be the first super early melt-out of Kara in a few years. That could help set the stage for a domino effect of impacts on the Siberian Seas from both ATL and PAC. I think things are lining up very badly for Beaufort, Chukchi, ESS, Laptev, and Kara.

Finally: the Okhotsk extent collapse has been severe and dramatic. Okhotsk is one of the two farthest regions from the Pole for significant icecover (the other being Hudson Bay / SE Canada). Now that Okhotsk is going and most of the SE Canada ice is gone (and Baffin is following), I wonder if Hudson's status as sole remaining area of thick ice could encourage a "stuck" weather pattern promoting ice retention there into May and June (with another late melt-out, though let's wait until June to gauge exactly when as it could be well into August this yr). Quebec is once again purple. And the ice in Hudson is certainly quite thick. This combination could also result in the continued ejection of Arctic / Greenland airmasses towards the Canadian -500MB anomaly centered over HB, leaving the aforementioned PAC / Siberian seas increasingly vulnerable.

Perhaps nothing to consider but it will be interesting to watch the 500MB pattern evolve as we head towards solstice and this is something I will be keeping an eye out for. It certainly seems to be occurring right now looking at April's 500MB anomaly map.

PPS: also attaching the last 30 days of temperature anomalies. The Eurasian heat is largely unprecedented IMO. I think this portends a very very nasty fire season across much of Siberia as well as the Rockies / Yukon. As the snowcover melts, these areas in red are going to turn into a blast furnace and there will be large plumes of dark carbon drifting into the Arctic by solstice, IMO.
Title: Re: The 2019 melting season
Post by: jdallen on April 07, 2019, 11:52:01 PM
This looks very broken up, more than usual?
For random visitors, this is the familiar North Shore of Greenland, the rounded fractures are on the Nares strait entrance, the webbed mesh of old ice is moving towards Fram strait.

I've certainly seen both this broken up but not sure if it was April. Perhaps on May. Betting the Bering strait is getting some strong currents northwards.

There have been years where the near-Fram CAB has been this broken up this early, perhaps not quite so finely divided.  I believe we are a few weeks early.
Title: Re: The 2019 melting season
Post by: Frivolousz21 on April 08, 2019, 05:17:36 AM
Unless there is a legit Arctic dipole anomaly with a negative NOA after May 15th through June.

what's happening now just won't cut it if you're looking for records without that.


I don't know if we can say we are due.

But we are due.
Title: Re: The 2019 melting season
Post by: El Cid on April 08, 2019, 07:34:19 AM
Although I also think that 2019 has a good chance of breaking previous records, if we look at extent maps, all we see is that 2019 is very similar to 2018 at this point. The difference with previous years is completely due to the Bering which has been going thru Pacification the past 2 years. This might be enough to break the proverbial camel's back. Or it might not. It was not enough in 2018...
Title: Re: The 2019 melting season
Post by: Aluminium on April 08, 2019, 08:18:52 AM
April 2-7.
Title: Re: The 2019 melting season
Post by: Killian on April 08, 2019, 08:48:36 AM
This looks very broken up, more than usual?
For random visitors, this is the familiar North Shore of Greenland, the rounded fractures are on the Nares strait entrance, the webbed mesh of old ice is moving towards Fram strait.

I've certainly seen both this broken up but not sure if it was April. Perhaps on May. Betting the Bering strait is getting some strong currents northwards.

There have been years where the near-Fram CAB has been this broken up this early, perhaps not quite so finely divided.  I believe we are a few weeks early.

More than usual, meaning average, certainly. This is the worst extent of breakup for Nares going all the way back to 2010 on these dates. 2010 was worse for the ice north of Greenland and the CArch. There was one other really bad year for basin ice... forget which.

Overall, anomalous and partly unprecedented. I've felt for years that the Nares acts like a bathtub stopper a little, creating room when it goes for more movement of the ice north of the CArch and Greenland, speeding up the whole darned thing, basically.

Nope, done no studies.

Anybody?
Title: Re: The 2019 melting season
Post by: Killian on April 08, 2019, 09:00:51 AM
BTW, is it my imagination or did we, according to JAXA, just blow through 1m km. sq. in six days? (Previous record for blowing through the 14m~13m range was 14 days if I'm reading the Petitt bar graph right.)
Title: Re: The 2019 melting season
Post by: oren on April 08, 2019, 11:05:57 AM
April 2-7.
It seems movement into the Kara and and the Chukchi has stopped in the last 2-3 days
Maybe there is a chance of some recovery.
Title: Re: The 2019 melting season
Post by: oren on April 08, 2019, 11:10:43 AM
BTW, is it my imagination or did we, according to JAXA, just blow through 1m km. sq. in six days? (Previous record for blowing through the 14m~13m range was 14 days if I'm reading the Petitt bar graph right.)
JAXA extent was at 14 million km2 on Mar22, so no. Perhaps you meant 13.5M to 13M?
Title: Re: The 2019 melting season
Post by: johnm33 on April 08, 2019, 11:12:26 AM
"speeding up the whole darned thing" There's constant pressure on the Atl. side trying to force water in to the Arctic, if Nares, and the CAA generally, blocks the surface flow then the fractions below the surface have to force their way out which calls for far more energy. If Nares is flowing freely then the speed of surface waters towards Greenland increases and more flows through Fram too dragging the ice with it. Then more Atl. water flows in and the most energetic fraction moves towards Kara the nursery for thick ice.
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 08, 2019, 11:23:21 AM
Is it my imagination or did we, according to JAXA, just blow through 1m km. sq. in six days?

14 mio was on March 22nd, so it seems you have a vivid imagination?
Title: Re: The 2019 melting season
Post by: Thawing Thunder on April 08, 2019, 12:17:59 PM
I've felt for years that the Nares acts like a bathtub stopper a little, creating room when it goes for more movement of the ice north of the CArch and Greenland, speeding up the whole darned thing, basically.


Little observation of a none native speaker: I found out that "nares" means "nostrils", I feel that is quite illustrative in this context.

Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 08, 2019, 12:32:25 PM
Little observation of a none native speaker: I found out that "nares" means "nostrils", I feel that is quite illustrative in this context.

That's some nice trivia. Thanks for sharing. :)

If you have a source, please, share with us in the Nares Strait thread.
Title: Re: The 2019 melting season
Post by: uniquorn on April 08, 2019, 01:21:45 PM
I have fixed the September 2019 map for everyone. I think all the FYI beyond the red line is incredibly thin this year and will be prone to severe melt ponding and very early melt-out. Wave action will take care of the MYI tendrils that remain. I know some / everyone disagrees but I think we are already seeing melt ponding begin to percolate through most areas beyond the red line thanks to recent weather. <snippage>
Having enjoyed your posts since I first lurked on the forum I followed this up further using worldview. https://go.nasa.gov/2FXt5r2
That wasn't conclusive so I compared 2012-2019 (first image) edit:forgot 2019
Quote
Corrected Reflectance (Bands 3-6-7)
Temporal coverage: 24 February 2000 - Present
False Color: Red = Band 3, Green = Band 6, Blue = Band 7
This combination is used to map snow and ice. Snow and ice are very reflective in the visible part of the spectrum (Band 3), and very absorbent in Bands 6 and 7 (short-wave infrared, or SWIR). This band combination is good for distinguishing liquid water from frozen water, for example, clouds over snow, ice cloud versus water cloud; or floods from dense vegetation. This band combination is only available for MODIS (Terra) because 70% of the band 6 sensors on the MODIS instrument on the Aqua satellite failed shortly after launch.
2019 doesn't stand out from previous years so I tried sentinel playground http://tinyurl.com/y3qfrhh8
Bingo! Looks like melt. Close to the coast at least. Dial the rhetoric back a bit and we have agreement. :) Similarly with Okhotsk melt which was predicted up forum due to southerly freeze and is normally quite steep.

Currently trending closer to red than magenta.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 08, 2019, 01:24:49 PM
Crackification on the Atlantic side continues.

This is a GIF showing recent 3 days north of Nares.

A massive crack evolved reaching all the way to the north of Svalbard.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 08, 2019, 03:12:08 PM
April 2-7.
It seems movement into the Kara and and the Chukchi has stopped in the last 2-3 days
Maybe there is a chance of some recovery.
There is at the moment
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 08, 2019, 04:46:52 PM
Northerly winds over the next 5 days will give the ice in the Laptev and Kara seas an opportunity for recovery, but then another powerful surge of warm air will flood in from the Atlantic. The GFS and ECMWF models disagree on the details of the low pressure areas, but agree on the big picture - the intense ridge that develops over Scandinavia and the powerful southerly flow that pushes into the Nordic seas.
Title: Re: The 2019 melting season
Post by: lanevn on April 08, 2019, 08:22:57 PM
Unless there is a legit Arctic dipole anomaly with a negative NOA after May 15th through June.

what's happening now just won't cut it if you're looking for records without that.


I don't know if we can say we are due.

But we are due.

And what's chances it will happen? I even heard that 2012 weather conditions is something like 1 vs 100, because previouse melting over 100% territory of Greenland happened more than 100 years ago. Were it really exceptional weather?
Title: Re: The 2019 melting season
Post by: uniquorn on April 08, 2019, 08:28:55 PM
Crackification on the Atlantic side continues.<>
Nice animation.

amsr2-uhh, okhotsk, jan1-apr7. Another sea where freezing started away from the coast despite the cold offshore winds. Is that because the wind was too strong, not cold enough or coastal upwelling? Either way, there is very little fast ice to offer resistance to drift into warmer southern water and a lot of flash freeze/melt, similar to bering.
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 08, 2019, 09:01:17 PM
Northerly winds over the next 5 days will give the ice in the Laptev and Kara seas an opportunity for recovery, but then another powerful surge of warm air will flood in from the Atlantic. The GFS and ECMWF models disagree on the details of the low pressure areas, but agree on the big picture - the intense ridge that develops over Scandinavia and the powerful southerly flow that pushes into the Nordic seas.

The Scandinavian High throws up some warm southerlies to the east of Greenland and then out over the Norwegian Sea but latest model offerings are suggesting this heat wont reach the Kara Sea. So a bit of a respite - but it will hardly stay lucky for many weeks longer.   :(
Title: Re: The 2019 melting season
Post by: oren on April 08, 2019, 09:16:59 PM
amsr2-uhh, okhotsk, jan1-apr7. Another sea where freezing started away from the coast despite the cold offshore winds. Is that because the wind was too strong, not cold enough or coastal upwelling? Either way, there is very little fast ice to offer resistance to drift into warmer southern water and a lot of flash freeze/melt, similar to bering.
I think this always happens in Okhotsk - freezing is driven by cold offshore winds, therefore no fast ice and real ice mostly generated away from shore.
Title: Re: The 2019 melting season
Post by: uniquorn on April 08, 2019, 09:31:38 PM
amsr2-uhh, okhotsk, jan1-apr7. Another sea where freezing started away from the coast despite the cold offshore winds. Is that because the wind was too strong, not cold enough or coastal upwelling? Either way, there is very little fast ice to offer resistance to drift into warmer southern water and a lot of flash freeze/melt, similar to bering.
I think this always happens in Okhotsk - freezing is driven by cold offshore winds, therefore no fast ice and real ice mostly generated away from shore.
Yes, you're right. I checked a couple of random years back to 2012 and they look similar.
Title: Re: The 2019 melting season
Post by: jai mitchell on April 08, 2019, 09:42:00 PM
OOF!!! feels like a gut punch.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 08, 2019, 10:05:04 PM
amsr2-uhh, okhotsk, jan1-apr7. Another sea where freezing started away from the coast despite the cold offshore winds. Is that because the wind was too strong, not cold enough or coastal upwelling? Either way, there is very little fast ice to offer resistance to drift into warmer southern water and a lot of flash freeze/melt, similar to bering.
I think this always happens in Okhotsk - freezing is driven by cold offshore winds, therefore no fast ice and real ice mostly generated away from shore.
Surely what matters is it looks like melt out may well be somewhat earlier than the 2010's average so yet another place with AWP above average -i.e. a sea warming up earlier and longer.
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 08, 2019, 11:41:20 PM
amsr2-uhh, okhotsk, jan1-apr7. Another sea where freezing started away from the coast despite the cold offshore winds. Is that because the wind was too strong, not cold enough or coastal upwelling? Either way, there is very little fast ice to offer resistance to drift into warmer southern water and a lot of flash freeze/melt, similar to bering.
I think this always happens in Okhotsk - freezing is driven by cold offshore winds, therefore no fast ice and real ice mostly generated away from shore.

Yes, you're right. I checked a couple of random years back to 2012 and they look similar.

I would consider it more ice pulling away/being driven away from the coast. Back on March 19 the ice was practically on the coastal edge but has pulled away southwards since. Not able now to re-freeze the gap left.

(in this gif, up is south ! )
Title: Re: The 2019 melting season
Post by: Jim Hunt on April 09, 2019, 11:30:26 AM
The first increase in extent since March 22nd:
Title: Re: The 2019 melting season
Post by: pauldry600 on April 09, 2019, 12:30:44 PM
A slowdown looks imminent for the coming week

Lead will decrease as a lot of fast melt areas are now thawed out and the conditions need to work on thicker ice.

Prob will accelerate once again in 7 to 10 days
Title: Re: The 2019 melting season
Post by: uniquorn on April 09, 2019, 01:42:52 PM
This looks very broken up, more than usual?
The north greenland fractures are similar to previous years but the lincoln sea makes it look worse this year. Thick ice build up on the north coast happened in 2016 but I think that was helped by more MYI from CAA. This year not so much MYI and more compaction from northern drift perhaps.
I only went back 2010-2019, worldview terra modis, north greenland, apr8 or nearest clear day.
https://go.nasa.gov/2UNrux8
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 10, 2019, 12:37:20 AM
Had a look back on the ESRL thickness chart in early April 2018 and compared with forecast chart for 13th of April this year.

The bright pink represents thickness of 1.6m or more. Comparing the two, Beaufort looks a bit better this year (despite the pessimism). Whereas Barents and Kara are worse.

Barents and Kara look like they will melt away quickly this year.
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 10, 2019, 05:28:15 AM
As a Newbie, let me see if I got this graph straight:
https://forum.arctic-sea-ice.net/index.php/topic,2591.msg194492.html#msg194492
As of April 9, the Arctic Sea Ice extent is the lowest it has been for this date in the last seven years, and presumably for all of human history back at least to the Sangamon Interglacial, if not the Pliocene?
Title: Re: The 2019 melting season
Post by: TenneyNaumer on April 10, 2019, 06:11:33 AM
The Arctic Oscillation Index is now pretty negative, which used to mean that melting slowed (during March, April, and May), but it's still heading south.  But the polar jet is crazier than ever.  If the Index stays negative and the melt continues apace, we are truly in new territory. 
Title: Re: The 2019 melting season
Post by: mabarnes on April 10, 2019, 10:58:13 AM
As a Newbie, let me see if I got this graph straight:
https://forum.arctic-sea-ice.net/index.php/topic,2591.msg194492.html#msg194492
As of April 9, the Arctic Sea Ice extent is the lowest it has been for this date in the last seven years, and presumably for all of human history back at least to the Sangamon Interglacial, if not the Pliocene?

I'm curious too ... a quick google search and I find stuff like this:
https://www.nature.com/articles/s41467-017-01884-8
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 10, 2019, 02:28:21 PM
As a Newbie, let me see if I got this graph straight:
https://forum.arctic-sea-ice.net/index.php/topic,2591.msg194492.html#msg194492
As of April 9, the Arctic Sea Ice extent is the lowest it has been for this date in the last seven years, and presumably for all of human history back at least to the Sangamon Interglacial, if not the Pliocene?

I would not go that far.  But it is at least as far back as 1979, as that is when the satellite data started.  Prior to that, we have more general and seasonal data.  There may have been brief periods of enhanced or retracted sea ice throughout history. 

https://www.pnas.org/content/112/15/4570
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 10, 2019, 03:50:32 PM
So, the consensus is pretty much that a BOA is coming in this Century, but we don't know if it will be in 2019 or 2090, although the former is more likely, and that it will be bad, but not as bad as Sam Carana (one of the better science fiction writers on the Web, IMHO) thinks it will be? Is that about the size of it?
BTW, I meant that in a good way, as science fiction being a spectacular story based on scientific fact.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 10, 2019, 04:03:25 PM
So, the consensus is pretty much that a BOA is coming in this Century, but we don't know if it will be in 2019 or 2090, although the former is more likely, and that it will be bad, but not as bad as Sam Carana (one of the better science fiction writers on the Web, IMHO) thinks it will be? Is that about the size of it?
BTW, I meant that in a good way, as science fiction being a spectacular story based on scientific fact.

Yes, the former is more likely. See image below.

I don't see Sam Carana as a fiction writer. I see him as an observer, who happens to be on the pessimistic side of the debate.

Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 10, 2019, 04:46:27 PM
He has recently upgraded his 10 C forecast for 2026 to 18 C. Do you really think AGW will be 18 C in seven years?
Title: Re: The 2019 melting season
Post by: Neven on April 10, 2019, 04:58:51 PM
Let's not discuss Sam Carana here. Or anywhere on this Forum, as far as I am concerned.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 10, 2019, 05:02:34 PM
He has recently upgraded his 10 C forecast for 2026 to 18 C. Do you really think AGW will be 18 C in seven years?

He did, eh?  ::)

No, i'm not that pessimistic. I think RPC 8.5 is realistic. Though i think the impacts of this scenario will be more severe than the IPCC estimates.
Title: Re: The 2019 melting season
Post by: oren on April 10, 2019, 06:03:36 PM
Tom, for BOE discussion go to the thread "When will the Arctic go ice-free". And forget Sam Carana.
Title: Re: The 2019 melting season
Post by: Shared Humanity on April 10, 2019, 06:08:21 PM
Tom, for BOE discussion go to the thread "When will the Arctic go ice-free". And forget Sam Carana.

Thank you for this.
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 10, 2019, 08:09:48 PM
Sam who?
Title: Re: The 2019 melting season
Post by: Shared Humanity on April 10, 2019, 08:26:16 PM
Sam who?

You post a comment mentioning Sam Carana and then post this?
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 10, 2019, 08:27:37 PM
Sam who?

You post a comment mentioning Sam Carana and then post this?

SH, Tom made a joke. :)
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 10, 2019, 08:32:10 PM
Sam who?

You post a comment mentioning Sam Carana and then post this?

SH, Tom made a joke. :)


Somehow, when you have to explain it, it's not as funny.
Title: Re: The 2019 melting season
Post by: uniquorn on April 10, 2019, 10:09:50 PM
uni-hamburg amsr2-uhh with dmi cice sea ice thickness inset, jan1-apr9.
I previously posted that atlantic export from the CAB was fairly neutral when looking at ascat but with better resolution on amsr2 it doesn't look like much ice stays behind the line between FJL and Svalbard.
edit:
Had a look back on the ESRL thickness chart in early April 2018 and compared with forecast chart for 13th of April this year.
I wonder why the Beaufort stringer isn't on that chart. That was good MYI. This year I think it is mostly second year ice. DMI cice tends to agree with ESRL though so ...
http://polarportal.dk/fileadmin/polarportal/sea/CICE_map_thick_LA_EN_20180409.png
Title: Re: The 2019 melting season
Post by: Aluminium on April 11, 2019, 07:03:12 AM
April 5-10.
Title: Re: The 2019 melting season
Post by: binntho on April 11, 2019, 08:53:52 AM
April 5-10.

If this had been posted two months ago I would have thought it showed an increase of at least a couple of centuries - but this is the melting season and although the curve has been flatlining for the last few days, I still can't get my head around this image showing the situation over the last few days.
Title: Re: The 2019 melting season
Post by: uniquorn on April 11, 2019, 11:28:23 AM
The last two animations don't show okhotsk. This might help to understand the extent numbers.
Title: Re: The 2019 melting season
Post by: binntho on April 11, 2019, 11:37:11 AM
The last two animations don't show okhotsk. This might help to understand the extent numbers.

You're right - Okhotsk has an almost vertical 400k drop.
Title: Re: The 2019 melting season
Post by: uniquorn on April 11, 2019, 01:57:02 PM
ESS, Worldview terra modis, apr4-11. Mobile ice comparable with 2017 and possibly 2011. https://go.nasa.gov/2G4Pu5H
Title: Re: The 2019 melting season
Post by: pauldry600 on April 11, 2019, 02:18:07 PM
Rather strangely and showing the complete volatility of Arctic Sea Ice I can see JAXA losing top position by next week after having led by 340k last week
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 11, 2019, 04:28:56 PM
There's going to be a blowtorch in the Barents in 5 to 6 days and temperatures will be well above normal over most of the sea ice covered areas in the NH. I don't see a sudden recovery coming. It does look like it will get cold in northern Siberia but that won't directly affect the ice.
Title: Re: The 2019 melting season
Post by: uniquorn on April 11, 2019, 07:38:00 PM
Tend to agree with FOoW and if the blowtorch is out I think it best the horses should go too. ;) There was an early dip in the Greenland Sea last year (extent not swimming). Perhaps this warm spell will have the same result. Ice south of Svalbard will also be challenged.

JAXA RGB shows the okhotsk. Here is jan1-apr10
https://ads.nipr.ac.jp/vishop/#/monitor/&time=2019-04-10%2000:00:00 
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 12, 2019, 03:35:07 PM
The amount of heat advected from the north Atlantic to the Atlantic side of the Arctic is going to be much greater than normal over the next 5 days. This atmospheric circulation pattern also increases the rate of flow of the Norwegian current into the Barents sea. storminess over the Atlantic side of the Arctic in mid April is not good for the sea ice because April would be cold and clear if there were high pressure and that would favor volume growth. This pattern favors volume loss over the ice pack margins and volume growth on north of Greenland on the exit doors to the Fram and Nares straits.
Title: Re: The 2019 melting season
Post by: El Cid on April 12, 2019, 07:12:04 PM
The amount of heat advected from the north Atlantic to the Atlantic side of the Arctic is going to be much greater than normal over the next 5 days. This atmospheric circulation pattern also increases the rate of flow of the Norwegian current into the Barents sea. storminess over the Atlantic side of the Arctic in mid April is not good for the sea ice because April would be cold and clear if there were high pressure and that would favor volume growth. This pattern favors volume loss over the ice pack margins and volume growth on north of Greenland on the exit doors to the Fram and Nares straits.

Just a few days ago I quoted this nice piece of research in another thread:

https://www.stevenphipps.com/publications/mauri2014.pdf

Basically, they say that during the pretty warm Holocene Optimum, the Scandinavian high (the persistent high pressure blocking zone) was probably very prevalent during summers. This could mean that with the current warming of the atmosphere this is likely to happen again.
Conclusion: warm and dry summers for the Brits and the Scandinavians, and further loss of ice and intrusion of warm water into the Arctic.
Title: Re: The 2019 melting season
Post by: Stephan on April 12, 2019, 07:35:56 PM
...and probably another warm and dry summer in Central Europe, at least in N and E Germany??
Wouldn't be good! >:(
Title: Re: The 2019 melting season
Post by: wallen on April 13, 2019, 02:33:13 AM
Have followed this site out of pure interest and concern for the last 4-5 years. Any comments I make just reflect a general observation, not a qualified assessment. The last few days in watching Worldview I cannot recall seeing the ice along the Greenland east coast breaking away so early in a melt season.
                     
Thoughts anyone ??
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 13, 2019, 01:25:05 PM
wallen, my thoughts are that it is fortunate for me that I may have joined this forum and begun following it quite possibly five months before a historic event.
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 13, 2019, 02:02:51 PM
Have followed this site out of pure interest and concern for the last 4-5 years. Any comments I make just reflect a general observation, not a qualified assessment. The last few days in watching Worldview I cannot recall seeing the ice along the Greenland east coast breaking away so early in a melt season.
                     
Thoughts anyone ??

You may want to visit one of the Greenland threads, and ask your question.  Gerontocrat seems rather informed on such, and has presented nice graphics.  It looks like Greenland ice is below average this year, largely due to the southeast coast.
Title: Re: The 2019 melting season
Post by: oren on April 13, 2019, 05:43:52 PM
I believe wallen refers to fast sea ice cracking and pulling away along the Greenland coast, and if so it belongs here.
I will attempt to browse Worldview tomorrow to see if anything is unptecedented.
Title: Re: The 2019 melting season
Post by: wallen on April 14, 2019, 01:49:49 AM
I believe wallen refers to fast sea ice cracking and pulling away along the Greenland coast, and if so it belongs here.
I will attempt to browse Worldview tomorrow to see if anything is unptecedented.

You are correct in your assessment Oren. Thank you.
Title: Re: The 2019 melting season
Post by: Avalonian on April 14, 2019, 05:45:46 AM
I believe wallen refers to fast sea ice cracking and pulling away along the Greenland coast, and if so it belongs here.
I will attempt to browse Worldview tomorrow to see if anything is unptecedented.

You are correct in your assessment Oren. Thank you.

I was looking at this, too. From what I've seen on Worldview, it's been an increasing trend since 2012: not quite unique but more dramatic this year than previously. In the past few years, summer Fram export has been minimal, so that cracked-up stuff mostly just loiters off the coast of Greenland, bobbing back and forth. If the Fram export is higher this year (as seems possible, so far), a lot of that broken stuff may just vanish southwards for once.
Title: Re: The 2019 melting season
Post by: Aluminium on April 14, 2019, 08:00:16 AM
April 8-13.
Title: Re: The 2019 melting season
Post by: Killian on April 14, 2019, 12:24:05 PM
In the past few years, summer Fram export has been minimal, so that cracked-up stuff mostly just loiters off the coast of Greenland, bobbing back and forth. If the Fram export is higher this year (as seems possible, so far), a lot of that broken stuff may just vanish southwards for once.

Indeed. So reduced I've been using it as a proxy for the melt season progress and so have barely paid attention to the of a new low since 2016 because Fram export is so strongly correlated to new lows. Just look to the EGS and Fram Strait and if there's a long, thick tail of ice, pay attention. If not, go do other things and leave the number stuff to all of you who have those chops.

I'm paying more attention this year, obviously.
Title: Re: The 2019 melting season
Post by: uniquorn on April 14, 2019, 01:45:28 PM
Worldview terra modis with heavy contrast to highlight the larger floes of, probably, thicker ice in the Beaufort 'stringer', apr13. Inset is the ascat image of roughly the same area. Mackenzie bay bottom left.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 14, 2019, 02:45:56 PM
AP: "Pace of Bering Sea changes startles scientists"
https://news.yahoo.com/bering-sea-changes-startle-scientists-worry-residents-160703816.html
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 14, 2019, 04:09:38 PM
Yes, Wallen, there has been a trend over the past 5 years or so to less shelf ice on the east coast of Greenland. This is having profound impacts. Mid to deep water formation has increased in the Greenland sea because salty water has cooled on the shelf then descended to deep water. This warm salty water is also melting glaciers from below, increasing their flow and melt rates.

There are papers on this and I'm sure someone here knows the links to some of them. I don't have the links at my command.

The NSIDC reports that the past 2 years have had very heavy snow on SE Greenland and that accumulation exceeded melting. This is associated with the tendency to a Greenland vortex that we've had for 2 years. In the big melt years of 2010 and 2012 high pressure (and a dome of warm air) dominated and warmed Greenland. https://nsidc.org/greenland-today/

As noted in the previous post, exceptional winter snow accumulation and heavy, summer snowfall, drove the net snow input mass to 130 billion tons above the 1981 to 2010 average. This was followed by a near-average melt and runoff period, resulting in a large net mass gain for the ice sheet in 2018 of 150 billion tons. This is the largest net gain from snowfall since 1996, and the highest snowfall since 1972. However, several major glaciers now flow significantly faster than in these earlier years. The net change in mass of the ice sheet overall, including this higher discharge of ice directly into the ocean, is not clear at this point but may be a smaller loss or even a small gain. This is similar to our assessment for 2017, and in sharp contrast to the conditions for the preceding decade.

This is relevant to this melting season because the incoming Atlantic water is saltier and warmer without Greenland melt water mixing in. Moreover, the Gulf Stream and Norwegian currents are strengthened by intensified overturning circulation and the stronger sea surface height gradients this pattern produces. The rate of sea ice and fresh water export in the Labrador sea has also increased with increasing flow out of the Nares and CAA.

We'll see what this summer's weather brings us, but this is setting up to be a bad melt year and the early break up of east Greenland fast ice is but one sign of it.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 14, 2019, 06:46:40 PM

The NSIDC reports that the past 2 years have had very heavy snow on SE Greenland and that accumulation exceeded melting. This is associated with the tendency to a Greenland vortex that we've had for 2 years.

....exceptional winter snow accumulation and heavy, summer snowfall, drove the net snow input mass to 130 billion tons above the 1981 to 2010 average. This was followed by a near-average melt and runoff period, resulting in a large net mass gain for the ice sheet in 2018 of 150 billion tons. This is the largest net gain from snowfall since 1996, and the highest snowfall since 1972.

However, several major glaciers now flow significantly faster than in these earlier years. The net change in mass of the ice sheet overall, including this higher discharge of ice directly into the ocean, is not clear at this point but may be a smaller loss or even a small gain. This is similar to our assessment for 2017, and in sharp contrast to the conditions for the preceding decade.

This is relevant to this melting season because the incoming Atlantic water is saltier and warmer without Greenland melt water mixing in. Moreover, the Gulf Stream and Norwegian currents are strengthened by intensified overturning circulation and the stronger sea surface height gradients this pattern produces. The rate of sea ice and fresh water export in the Labrador sea has also increased with increasing flow out of the Nares and CAA.

We'll see what this summer's weather brings us, but this is setting up to be a bad melt year and the early break up of east Greenland fast ice is but one sign of it.

Greenland Precipitation:- This year is different from the previous 2 years, in that up to the beginning of April precipitation was well below normal, except in SE Greenland. The anomaly map from DMI shows this impressive NW / SE variation.

However, since the beginning of April precipitation has been very much above average, and it looks like staying that way for the next 10 days at least. Not only is that additional precipitation again expected to be concentrated in the SE, much of that precipitation may be a mixture of snow and rain, at least at low altitude. So what the gain in SMB will be by the beginning of the melt season is anybody's guess?

And the latest news from Germany on the GRACE Follow-on mission is that science quality data currently being collected may start to be published by end of May. Greenland overall net mass loss since early 2017 will then hopefully be available.
Title: Re: The 2019 melting season
Post by: Shared Humanity on April 14, 2019, 07:56:35 PM
That net loss in the center of the ice sheet is a little troubling.
Title: Re: The 2019 melting season
Post by: Stephan on April 14, 2019, 08:54:10 PM
As it is recorded since Sep 1 I think that there couldn't hace occurred any melting since then, at least not in higher altitudes (> 300 m). Where does this mass loss come from? Snow drift by strong winds? Sublimation? Compaction (and therefore no mass loss, but slight elevation change, interpreted as mass loss)? I have no idea...
Title: Re: The 2019 melting season
Post by: uniquorn on April 14, 2019, 10:17:48 PM
A comparison of mercator(model) 0m salinity, feb1-apr13, 2018 and 2019. Originally looking at the bering and laptev seas but including greenland here for background info. The difference between the two years is more apparent in the Baffin at 0m where the model indicates it is notably more saline.

Meanwhile the laptev sea has it's own story to tell. (according to the model)
edit: forgot scale
Title: Re: The 2019 melting season
Post by: johnm33 on April 14, 2019, 10:45:24 PM
"That net loss in the center of the ice sheet is a little troubling."
 I've mostly been focussed on the losses through Jakobshvn and since there's no extra loss, as ice, above the surface it has to be lost as liquid below?
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on April 14, 2019, 11:57:57 PM
How do you get Gifs from Ascat?

https://www.ospo.noaa.gov/Products/atmosphere/ascat/ice.html
Title: Re: The 2019 melting season
Post by: mabarnes on April 15, 2019, 12:19:25 AM
As it is recorded since Sep 1 I think that there couldn't hace occurred any melting since then, at least not in higher altitudes (> 300 m). Where does this mass loss come from? Snow drift by strong winds? Sublimation? Compaction (and therefore no mass loss, but slight elevation change, interpreted as mass loss)? I have no idea...

I believe that's a map of ANOMALY - so the areas in red have less mass buildup than baseline buildup-to-date (not mass loss); likewise, those in blue show greater than baseline buildup. 

Here's the melt map for total melt this season:
Title: Re: The 2019 melting season
Post by: Klondike Kat on April 15, 2019, 02:25:19 AM
The Nenena ice classic set a new record early breakup date; beating the record by a full six days!
Title: Re: The 2019 melting season
Post by: oren on April 15, 2019, 06:31:44 AM
wallen ... fast sea ice cracking and pulling away along the Greenland coast.
I will attempt to browse Worldview tomorrow to see if anything is unprecedented.
Looking at Worldview it seems previous years had similar fast ice contours, for example 2016, and maybe 2014 and others.
If you see a specific location where you think this is not the case, please point out more specifically.
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 15, 2019, 09:39:23 AM
The Nenena ice classic set a new record early breakup date; beating the record by a full six days!

Indeed. Even the 1940s do not come close.
Title: Re: The 2019 melting season
Post by: uniquorn on April 15, 2019, 11:33:32 AM
How do you get Gifs from Ascat?
I recommend reading this thread.
https://forum.arctic-sea-ice.net/index.php/topic,1259.msg138784.html#msg138784
Title: Re: The 2019 melting season
Post by: Sterks on April 15, 2019, 03:18:13 PM
ECMWF shows for several days the high pressure system being maintained and even strengthen over the Gyre, that can produce early open water and leads along the coasts of Beaufort. Should refreeze, but not stay frozen for long.
Title: Re: The 2019 melting season
Post by: sark on April 15, 2019, 03:45:42 PM
Ever seen a jet stream at the north pole before?
Title: Re: The 2019 melting season
Post by: Neven on April 15, 2019, 04:06:01 PM
ECMWF shows for several days the high pressure system being maintained and even strengthen over the Gyre, that can produce early open water and leads along the coasts of Beaufort. Should refreeze, but not stay frozen for long.

I had expected to see the Beaufort open up ever so slightly already, given the winds have been blowing away from the coast - grosso modo- for a while now. Seems I was wrong.
Title: Re: The 2019 melting season
Post by: Ktb on April 15, 2019, 05:49:39 PM
Slater projection is running again. Continuing to be quite accurate.

It appears to me that the prediction of 11.15 million km^2 for June 3rd does not match the ice shown in the image. In fact, it looks like the ice of today. They had this problem last season, and never rectified it.
Title: Re: The 2019 melting season
Post by: Sterks on April 15, 2019, 11:35:55 PM
ECMWF shows for several days the high pressure system being maintained and even strengthen over the Gyre, that can produce early open water and leads along the coasts of Beaufort. Should refreeze, but not stay frozen for long.

I had expected to see the Beaufort open up ever so slightly already, given the winds have been blowing away from the coast - grosso modo- for a while now. Seems I was wrong.
Quite some open areas already, they refreeze immediately
Title: Re: The 2019 melting season
Post by: slow wing on April 15, 2019, 11:39:33 PM
Slater projection is running again. Continuing to be quite accurate.

It appears to me that the prediction of 11.15 million km^2 for June 3rd does not match the ice shown in the image. In fact, it looks like the ice of today. They had this problem last season, and never rectified it.
It's probabilistic, as they explain. (http://cires1.colorado.edu/~aslater/SEAICE/about.html)
"Do not mistake the blue colored areas as being a simplified extent forecast."
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 15, 2019, 11:51:48 PM
I had expected to see the Beaufort open up ever so slightly already, given the winds have been blowing away from the coast - grosso modo- for a while now. Seems I was wrong.

NWS Anchorage break up outlook for the chukchi (issued at the end of March) :suggesting Chukchi could be a bit slower this year

"Looking at the big picture for the Chukchi Sea, sea ice is
relatively thick compared to the past couple winters through much of the Chukchi Sea. There is also an area of multi-year sea ice that has drifted through the central Chukchi Sea as far south as the waters offshore from Icy Cape. While sea ice along the coastline will likely break up slightly slower than last year, the area of multi-year sea ice will likely linger offshore quite a bit longer.."
Title: Re: The 2019 melting season
Post by: Ktb on April 16, 2019, 03:50:03 AM

It's probabilistic, as they explain. (http://cires1.colorado.edu/~aslater/SEAICE/about.html)
"Do not mistake the blue colored areas as being a simplified extent forecast."

Reading is hard
Title: Re: The 2019 melting season
Post by: psymmo7 on April 16, 2019, 08:14:26 AM
Falling Records

Will this be the next one?

http://www.yukonriverbreakup.com/

The April 15 picture doesn't look encouraging

Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 16, 2019, 07:26:33 PM
Are melting ponds expected at this time of the year in Baffin Bay?

Link >> https://apps.sentinel-hub.com/sentinel-playground/?source=S2&lat=77.25940114515242&lng=-78.3211898803711&zoom=11&preset=CUSTOM&layers=B01,B02,B03&maxcc=73&gain=1.0&gamma=1.0&time=2018-10-01%7C2019-04-15&atmFilter=&showDates=true&evalscript=cmV0dXJuIFtCOEEqMSxCMDMqMSxCMDIqMV0%3D

(Click to play)
Title: Re: The 2019 melting season
Post by: magnamentis on April 16, 2019, 09:03:09 PM
Are melting ponds expected at this time of the year in Baffin Bay?

Link >> https://apps.sentinel-hub.com/sentinel-playground/?source=S2&lat=77.25940114515242&lng=-78.3211898803711&zoom=11&preset=CUSTOM&layers=B01,B02,B03&maxcc=73&gain=1.0&gamma=1.0&time=2018-10-01%7C2019-04-15&atmFilter=&showDates=true&evalscript=cmV0dXJuIFtCOEEqMSxCMDMqMSxCMDIqMV0%3D

(Click to play)

melt ponds can happen that far south, yes, just not on big scale and not in the central arctic up north, exceptions confirm the rules as usual.

i'm surprised that the ice is thick enough for ponds not falling through LOL [JK]
Title: Re: The 2019 melting season
Post by: Stephan on April 16, 2019, 09:08:53 PM
Falling Records

Will this be the next one?

http://www.yukonriverbreakup.com/

The April 15 picture doesn't look encouraging
A graph with decadal averages would be nice to see a tendency whether the breakup is moved to earlier dates. From a glimpse on the table one could guess that the breakup has moved a little bit, but this needs further statistical analyses.
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 16, 2019, 10:07:10 PM
Are melting ponds expected at this time of the year in Baffin Bay?


Nullschool was showing peak temperatures in that location of -18 C. So not now.

Trick of the rendering.
Title: Re: The 2019 melting season
Post by: magnamentis on April 16, 2019, 11:38:32 PM
Are melting ponds expected at this time of the year in Baffin Bay?


Nullschool was showing peak temperatures in that location of -18 C. So not now.

Trick of the rendering.

i should have used the link that points way north, hence you're right of course

talking about baffin bay, i was a bit more south in my thoughts the lead to the answer, i.e. sisimut belongs to baffin bay as well and is around -8 right now and can be -4 at times at this time of the year and the sun down there is not sooo... weak anymore now, hence considering his link the answer is "not very probable or dunno" talking all baffin bay it's possible, there is even open water in parts.

thanks for making me look again more thoroughly, next time i'll look it up first before shooting away. ;)
Title: Re: The 2019 melting season
Post by: Sebastian Jones on April 17, 2019, 05:11:19 AM
Falling Records

Will this be the next one?

http://www.yukonriverbreakup.com/

The April 15 picture doesn't look encouraging
A graph with decadal averages would be nice to see a tendency whether the breakup is moved to earlier dates. From a glimpse on the table one could guess that the breakup has moved a little bit, but this needs further statistical analyses.
Break up has definitely occurred earlier in recent years. I do not have an updated graph handy- but i should make one- I wish I were better at excel....Because of the inertia associated with ice melt, breakup tends to damp out short term weather and, on average, the date of breakup tracks very well with climate trends- later early in the 20th century, warm in the 1940s, trending later into the early 1960s and a gradual warming trend side then,  which appears to be accelerating, although it is too soon to see this from the data. I do not think 2019 will break the 2016  record, but it has a really good shot at second place. OK, I found my old graph, I'll work on updating it....
Title: Re: The 2019 melting season
Post by: Sebastian Jones on April 17, 2019, 07:56:30 AM
OK, here is my crappy graph- many thanks to Oren for explaining how to attach it...Advance apologies that the April dates appear as negative May dates....Nonetheless, the trend is clear, breakup is a week earlier than a century ago. Something similar is evident regarding freeze up too, but freeze up is way more complex because it is affected by river height, which drops during fall.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 17, 2019, 08:44:06 AM


Nullschool was showing peak temperatures in that location of -18 C. So not now.

Trick of the rendering.

Thanks guys! :)
Title: Re: The 2019 melting season
Post by: Aluminium on April 17, 2019, 09:37:33 AM
April 11-16.
Title: Re: The 2019 melting season
Post by: oren on April 17, 2019, 09:55:33 AM
April 11-16.
So the Chukchi and Kara managed to stage a comeback of sorts. But the Bering did not and is over for the season, and now the Beaufort open water does not refreeze anymore.
Title: Re: The 2019 melting season
Post by: uniquorn on April 17, 2019, 11:36:39 AM
uni-hamburg amsr2-uhh, greenland, apr10-16.
wipneus regional extent  https://sites.google.com/site/arcticseaicegraphs/regional
Southerlies likely to be dominant for the next two days.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 17, 2019, 04:18:03 PM
April 11-16.
So the Chukchi and Kara managed to stage a comeback of sorts. But the Bering did not and is over for the season, and now the Beaufort open water does not refreeze anymore.
The Chukchi was a partial recovery (not yet finished?).
The Kara and Laptev have staged complete recovery.
The Beaufort is just dithering around the max.
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 17, 2019, 05:59:39 PM
There has been a major shift in the atmospheric circulation pattern around the Arctic. The ridging which persisted over Alaska in February and March has ended while a strong ridge has set up over Scandinavia. This has allowed for an apparent recovery on the Alaskan side of the Arctic, although the reformed ice is very thin and won't last long. The heat on the Atlantic side won't show large effects on metrics because it is going over thick ice that was piled up at the exit to the Fram strait.

One not so good thing for sea ice about this atmospheric circulation pattern is that the coldest anomaly is focused on Baffin bay with strong north winds down the bay. This will enhance the circulation of warm salty water into the bay along the coast of Greenland and the flow of icy fresh water out of the bay into the Labrador sea. This will favor continued overturning in the Labrador sea and the release of oceanic heat to atmosphere over the far north Atlantic and subpolar seas.
Title: Re: The 2019 melting season
Post by: Stephan on April 17, 2019, 10:35:24 PM
OK, here is my crappy graph- ....
Thank you Sebastian. The trend is clearly going down, and it is of course overlaid by individual weather patterns each year, whose influence is bigger than the trendline which makes the graph look very "spiky". But this is normal for these kind of graphs.
Title: Re: The 2019 melting season
Post by: Sterks on April 18, 2019, 01:14:21 PM
 Current high pressures sustained, and strengthen to dominate the Arctic for a week, must widen the already existing gaps of Beaufort coasts.
Early open water has been key to melt the Beaufort and make a strong melting season
Title: Re: The 2019 melting season
Post by: SimonF92 on April 18, 2019, 05:20:36 PM
Everything looking pretty terrible then, should be a good season on here in that case
:)
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 18, 2019, 05:45:27 PM
guyonclimate discusses starting changes in Bering Sea:
http://www.guyonclimate.com/2019/04/16/extreme-temperature-diary-april-15th-2019-astonishing-bering-sea-changes/
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on April 18, 2019, 08:56:14 PM

It also looks like the melt of the Great Slave Lake is early. Watch for an early break up of the Mackenzie

Title: Re: The 2019 melting season
Post by: El Cid on April 19, 2019, 09:06:13 AM
Before everyone gets superexcited about low extent numbers, we must realize that 2019 is very much the same as 2018 in the (inner) seas that matter. The difference between the two is that 2018 had much bigger Okhotsk Sea extent but that is irrelevant as the Okhotsk melts out anyway. See attachment. So, basically 2018 was the same as 2019 at this point.

It is true though that Pacification is very obvious in the past two years as never in previous years have we seen such an open Bering. What it means for the final, September numbers is still anybody's guess. It did not really matter last year, it might matter this year.

Title: Re: The 2019 melting season
Post by: oren on April 19, 2019, 10:52:49 AM
Before everyone gets superexcited about low extent numbers, we must realize that 2019 is very much the same as 2018 in the (inner) seas that matter. The difference between the two is that 2018 had much bigger Okhotsk Sea extent but that is irrelevant as the Okhotsk melts out anyway. See attachment. So, basically 2018 was the same as 2019 at this point.

It is true though that Pacification is very obvious in the past two years as never in previous years have we seen such an open Bering. What it means for the final, September numbers is still anybody's guess. It did not really matter last year, it might matter this year.
2019 is also lower in Baffin Bay (despite the active Nares export) and higher in the Greenland Sea. But it's true that a low extent at this time of year manifests itself in the outer seas, and isn't necessarily indicative of a bad melt year. It does increase the risk somewhat however.
Title: Re: The 2019 melting season
Post by: jdallen on April 19, 2019, 10:54:49 AM
Before everyone gets superexcited about low extent numbers, we must realize that 2019 is very much the same as 2018 in the (inner) seas that matter. The difference between the two is that 2018 had much bigger Okhotsk Sea extent but that is irrelevant as the Okhotsk melts out anyway. See attachment. So, basically 2018 was the same as 2019 at this point.

It is true though that Pacification is very obvious in the past two years as never in previous years have we seen such an open Bering. What it means for the final, September numbers is still anybody's guess. It did not really matter last year, it might matter this year.
I've been pondering along the same lines.  The Okhotsk is irrelevant to what will be happening in a few weeks. 

The Bering is another matter. It's unclear me what charge of increased heat it is carrying and how much of it will pass in to the Chukchi.

Over all, I see open water in the peripheral seas far more relevant to the refreeze, when they create a heatvreserve that slows freezing in the central seas.

Weather in the central basin, coastal Alaska and Siberia are now key.  How soon the rivers break up and when we see melt ponds is where things will hang in the balance.

The recent cooling has been hopeful and helpful, but I'm unsure if it is enough to check the momentum.
Title: Re: The 2019 melting season
Post by: dosibl on April 19, 2019, 03:43:39 PM
I'm sure this is a line of research somewhere that I'm just not familiar with, but I would think that the early melt in the Okhotsk could impact the inner seas by partially participating in the large scale weather patterns we'll encounter over the summer. The effect might be positive, negative, or mostly a wash, but all things being equal I think I'd prefer more ice.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 19, 2019, 04:27:51 PM
Early melt matters when considering global heating. Over 90% of the additional energy trapped by increased CO2 concentrations ends up in the oceans. Early melt dramatically increases the ability of the ocean at high latitudes to absorb heat during the period of maximum radiation that has started now.

You can see from the attached graphs from Tealight that 2016 had a far greater impact on the capacity of the Arctic Ocean to absorb heat than did 2012, simply because the melting happened early. At this moment in time in 2019 there is in excess of 500,000 km2 of the Arctic that is open water compared with the 2010's average. That's about 12 days ahead of the 2010's average.

Even if melt from now is pretty average or a bit low it is likely that accumulated Albedo Warming Potential in 2019 will exceed that of 2012.
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on April 19, 2019, 05:25:19 PM
Before everyone gets superexcited about low extent numbers, we must realize that 2019 is very much the same as 2018 in the (inner) seas that matter. The difference between the two is that 2018 had much bigger Okhotsk Sea extent but that is irrelevant as the Okhotsk melts out anyway. See attachment. So, basically 2018 was the same as 2019 at this point.

It is true though that Pacification is very obvious in the past two years as never in previous years have we seen such an open Bering. What it means for the final, September numbers is still anybody's guess. It did not really matter last year, it might matter this year.
I've been pondering along the same lines.  The Okhotsk is irrelevant to what will be happening in a few weeks. 

The Bering is another matter. It's unclear me what charge of increased heat it is carrying and how much of it will pass in to the Chukchi.

Over all, I see open water in the peripheral seas far more relevant to the refreeze, when they create a heatvreserve that slows freezing in the central seas.

Weather in the central basin, coastal Alaska and Siberia are now key.  How soon the rivers break up and when we see melt ponds is where things will hang in the balance.

The recent cooling has been hopeful and helpful, but I'm unsure if it is enough to check the momentum.

Early open water is important because of the increased heat the surface is going to absorb through insolation. If the peripheral seas become warmer, I'd expect there to be higher humidity air reaching the Arctic. Is that good or bad for the preservation of sea ice? More cloud, more heat advected from lower latitudes, but less sunlight.
Title: Re: The 2019 melting season
Post by: uniquorn on April 20, 2019, 12:01:47 AM
Worldview terra modis, amundsen gulf, apr10-19.
Worldview terra modis, amundsen gulf, apr18(or nearest) 2010-2019.
Title: Re: The 2019 melting season
Post by: jdallen on April 20, 2019, 12:33:16 AM
Before everyone gets superexcited about low extent numbers, we must realize that 2019 is very much the same as 2018 in the (inner) seas that matter. The difference between the two is that 2018 had much bigger Okhotsk Sea extent but that is irrelevant as the Okhotsk melts out anyway. See attachment. So, basically 2018 was the same as 2019 at this point.

It is true though that Pacification is very obvious in the past two years as never in previous years have we seen such an open Bering. What it means for the final, September numbers is still anybody's guess. It did not really matter last year, it might matter this year.
I've been pondering along the same lines.  The Okhotsk is irrelevant to what will be happening in a few weeks. 

The Bering is another matter. It's unclear me what charge of increased heat it is carrying and how much of it will pass in to the Chukchi.

Over all, I see open water in the peripheral seas far more relevant to the refreeze, when they create a heatvreserve that slows freezing in the central seas.

Weather in the central basin, coastal Alaska and Siberia are now key.  How soon the rivers break up and when we see melt ponds is where things will hang in the balance.

The recent cooling has been hopeful and helpful, but I'm unsure if it is enough to check the momentum.

Early open water is important because of the increased heat the surface is going to absorb through insolation. If the peripheral seas become warmer, I'd expect there to be higher humidity air reaching the Arctic. Is that good or bad for the preservation of sea ice? More cloud, more heat advected from lower latitudes, but less sunlight.
Again,I think the effect is more important to the refreeze.  More moisture in summer is more neutral possibly leading to negative feedbacks by increasing albedo with clouds.  Phase changes  won't be as important as temperatures are already  close to freezing, unless we ate talking about tropical scale imports of moisture,but those won't be from peripheral seas.
Title: Re: The 2019 melting season
Post by: magnamentis on April 20, 2019, 01:16:20 AM
Early open water is important because of the increased heat the surface is going to absorb through insolation. If the peripheral seas become warmer, I'd expect there to be higher humidity air reaching the Arctic. Is that good or bad for the preservation of sea ice? More cloud, more heat advected from lower latitudes, but less sunlight.

to emphasize your assumption about moisture:

whoever wants to follow the barrows webcam on a regular basis can see that whenever there is open water (lead) off that coast, one can observe a fog band exactly over the lead, nicely and steady in place whenever there are no higher winds.

it's very obvious that the lead is producing that fog/cloud above it and that illustrates your point very well, what you see in the attached image is not an exception but the norm.

this is independent of the discussion what prevails, higher albedo or more moisture but then i think it depends on the season, when which condition applies, exactly as it was posted by [JD] while i'm not so sure whether the retention of heat outperforms the lack of direct sunlight, will have a close look like every season. the last few summers indicated that clouds are good for the ice in high summer, let's see.

http://feeder.gina.alaska.edu/webcam-uaf-barrow-seaice-images/current/image
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 20, 2019, 02:10:39 PM
Cloud and inversion physics is very complicated. Different types of clouds have different effects on heat balances. And similar cloud types may have different impacts in March and April than in May and June. We need to be more specific in our discussions of the effects of clouds on ice for them to have any usefulness in understanding or predicting ice behavior.

One thing is very clear, however, and that is the negative impacts of warm air incursions from the Atlantic or Pacific oceans into the Arctic during the cold months. These warm cloudy situations associated with northward moving storms are becoming more frequent and are one major cause of the decline of arctic sea ice.

On the other hand, stormy weather in the months of May, June and July since the summer of 2012 has kept September ice minima well above the 2012 record low.

Water vapor levels are another matter. Increasing levels of water vapor are a powerful feedback in Arctic warming because water vapor is a potent greenhouse gas.
Title: Re: The 2019 melting season
Post by: Sterks on April 20, 2019, 03:27:42 PM
During next week the open water will keep increasing in extent from Beaufort coasts, and, shortly, refreezing. This is not 2016 as that was like intermittently from February to May and very strong, but it should be relevant anyway.
Getting warmer too.
Title: Re: The 2019 melting season
Post by: iceman on April 20, 2019, 04:34:37 PM
.... At this moment in time in 2019 there is in excess of 500,000 km2 of the Arctic that is open water compared with the 2010's average. That's about 12 days ahead of the 2010's average.
....

And the missing ice is disproportionately at lower latitudes: more exposed to insolation a month or two before the solstice. Big question is how much of the excess heat absorbed by open water in the Bering finds its way into the main Arctic basin.
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 20, 2019, 07:05:11 PM
Thin clouds close to the surface of sea or land ice that are caused by ice chilling of warmer air above have the potential to transmit huge amounts of heat to the ice. Because of the inversion, there is little mixing  with the air above so surface solar heating doesn't go back into the air above the inversion. Obviously, thick clouds may be very reflective and protective to the ice below. Understanding cloud types and how they are changing as the Arctic warms and ice melts will be a key to predicting Arctic change. The recent discovery of these thin near surface clouds that increase warming rates is one explanation for the failure of older models to predict the rapidity of Arctic warming.
Title: Re: The 2019 melting season
Post by: Neven on April 21, 2019, 12:33:12 AM
Ice and snow, 2016 vs 2019:
Title: Re: The 2019 melting season
Post by: bbr2314 on April 21, 2019, 08:50:53 AM
The EURO has been hinting at dual 500MB blocks over the NPAC / Bering and Greenland and tonight's 00z run certainly ups the ante re: Bering...!

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042100/ecmwf_z500_mslp_nhem_10.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042100/ecmwf_T850_namer_10.png)
Title: Re: The 2019 melting season
Post by: uniquorn on April 21, 2019, 01:00:06 PM
Nares competing with Fram for export catchment area.
Worldview viirsbt15n, north greenland apr20-21.  https://go.nasa.gov/2UMYBC5
edit: still cold at ~-27C
Title: Re: The 2019 melting season
Post by: uniquorn on April 21, 2019, 04:29:20 PM
50 days of ascat hopefully working better for mac users
Thanks to Sleepy for the ffmpeg conversion.
Title: Re: The 2019 melting season
Post by: oren on April 21, 2019, 08:11:18 PM
It seems that in the last week or two the movement of thick old ice towards the Atlantic has stalled. Good news, especially if it continues like this.
Title: Re: The 2019 melting season
Post by: Neven on April 21, 2019, 09:33:50 PM
It seems that in the last week or two the movement of thick old ice towards the Atlantic has stalled. Good news, especially if it continues like this.

Maybe not so much towards Fram directly, but the forecast is for some ice to get shoved towards Franz Josef Land a couple of days from now. Pressure remains (very) high over the Pacific side, with a very narrow band of isobars in the coming three days, which will inevitably continue to pull the ice in the Beaufort Sea westwards, furthering disintegration in Amundsen Bay, and causing more open water that I'm not sure will re-freeze that well anymore (see animation of the region for the past 5 days, below the forecast).

I expect this weather to abate come May, as it usually does, but if it doesn't, the Pacific side is going to take a serious beating.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on April 21, 2019, 10:44:04 PM
Uniquorn's 50-day movie reminds me of the report (maybe in a publication referenced in Icy Seas years ago?) that in 2007 (a year where Nares Strait never closed) Nares Strait ice export was 10% of that of Fram Strait. 
Title: Re: The 2019 melting season
Post by: bbr2314 on April 21, 2019, 10:45:22 PM
Yikes!

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042112/ecmwf_z500_mslp_nhem_9.png)
Title: Re: The 2019 melting season
Post by: Neven on April 21, 2019, 11:05:07 PM
Yikes!

8 days from now. Please, try to emphasize when you post forecasts beyond 6 days, because they're unreliable, and the writing on that map is small.
Title: Re: The 2019 melting season
Post by: DavidR on April 22, 2019, 02:01:40 AM
Yikes!
What is a Yike  ;D and how does it relate to that image? I  presume you  are expecting  something dramatic but have no idea what it is.  :o
Title: Re: The 2019 melting season
Post by: bbr2314 on April 22, 2019, 03:16:10 AM
Yikes!
What is a Yike  ;D and how does it relate to that image? I  presume you  are expecting  something dramatic but have no idea what it is.  :o
As Neven said it is 8 days out, but the map shows a major low pressure system impacting the Bering, Chukchi, and Beaufort with +0C warmth and significant wind, waves, and likely rain as well.
Title: Re: The 2019 melting season
Post by: Rodius on April 22, 2019, 03:59:52 AM
Given the unreliable nature of forecasts beyond 5 days, why use them?
Title: Re: The 2019 melting season
Post by: bbr2314 on April 22, 2019, 04:13:00 AM
Given the unreliable nature of forecasts beyond 5 days, why use them?
You don't have to! It isn't like the EURO is the most reliable forecast model on the planet and usually within the ballpark from days 6-10 even if details change substantially. It is currently indicating a heightened probability for the aforementioned LP / melt event to occur, ignore it if you  please.  :)
Title: Re: The 2019 melting season
Post by: jdallen on April 22, 2019, 05:06:52 AM
The EURO has been hinting at dual 500MB blocks over the NPAC / Bering and Greenland and tonight's 00z run certainly ups the ante re: Bering...!
There really isn't anything *left* in the Bering.

I'm more concerned about the Chukchi.

(Image from the Bering 2 days ago added for emphasis)

And yes, 6-10 days out, however great the service is still outside the event horizon as far as any ability on our part to reliably make assumptions is concerned.

BBR, please be patient.  Things are evolving.  We really don't have a sense of just how bad it will be yet, and we are far from really being able to see a sensible trend in the central basin, or even in the directly adjacent seas.
Title: Re: The 2019 melting season
Post by: sark on April 22, 2019, 06:12:23 AM
Given the unreliable nature of forecasts beyond 5 days, why use them?

Why produce them?  Because they are useful
Title: Re: The 2019 melting season
Post by: Viggy on April 22, 2019, 06:51:39 AM
Yikes!
... it is 8 days out, but the map shows a major low pressure system impacting the Bering, Chukchi, and Beaufort with +0C warmth and significant wind, waves, and likely rain as well.

'Yikes' obviously garners more sensationalist attention (whatever the purpose of that is), than a reasoned explanation of a complicated image (which bbr is also capable of providing).
Title: Re: The 2019 melting season
Post by: Rodius on April 22, 2019, 06:57:24 AM
Given the unreliable nature of forecasts beyond 5 days, why use them?

Why produce them?  Because they are useful

They can produce them and improve on them, but seeing them time and time again on here is confusing and then the prediction dont get measured against the eventual outcomes.

I am all for predictions, just not ten days out using unreliable tools.
I would rather see a thread for ten day projections that marries up the forecast then compares the forecast to what eventuates just to have a clear example of how good they are. That way it becomes clear just how good or not they are.

At worst, at least state at the top of the post that the projection is beyond 5 or 6 days so I can skip right past them.

Grip over with :)
Back to lurking
Title: Re: The 2019 melting season
Post by: El Cid on April 22, 2019, 10:49:29 AM
This is from the ECMWF site:

https://confluence.ecmwf.int//display/FUG/4.1+Forecast+Error+Growth

"Small baroclinic systems or fronts are currently well forecast to around Day2, cyclonic systems to around Day4 and the long planetary waves defining weather regimes to around Day8.  As models improve over time these limits are expected to advance further ahead of the data time.  Features that are coupled to the orography (e.g. lee-troughs), or to the underlying surface (e.g. heat lows), are rather less consistently well forecast."

In this sense brr is right: although the details will change, but major weather-systems - according to ecmwf - are USUALLY forecastable for 8 days.

To check the standard deviation between the ensemble members, ie. to see how reliable the forecast is, ECMWF shows this as well with colours:

https://www.ecmwf.int/en/forecasts/charts/catalogue/plot_ensm_essential?facets=Range,Medium%20(15%20days)&time=2019042112,120,2019042612&parameter=MSLP&area=Northern%20Hemisphere

Title: Re: The 2019 melting season
Post by: El Cid on April 22, 2019, 11:06:49 AM
Two more charts about the reliability of forecasts if you don't mind:

1.500hpa geopotential is quite reliable for 6-7 days:

"The plot shows for each month the range at which the month mean (blue line) or 12-month mean centred on that month (red line) of forecast anomaly correlation dropped below 80%. The score for the northern hemisphere extra-tropics is a primary headline score of the ECMWF HRES.

Anomaly correlation scores are spatial correlation between the forecast anomaly and the verifying analysis anomaly; anomalies are computed with respect to ERA-Interim-based climate. Verification follows updated WMO/CBS guidelines as specified in the Manual on the GDPFS, Volume 1, Part II, Attachment II.7, Table F, (2010 Edition - Updated in 2012)."

2. 850 hpa temps are somewhat reliable until day8/9:

"The plot shows for each month the range at which the 3-month mean (blue line) or 12-month mean (red line) centred on that month of the continuous ranked probability skill score of the 850hPa temperature ENS dropped below 25%. This is a primary headline score for the ECMWF ENS.

The continuous ranked probability score (CRPS) compares the probability distribution of the quantity forecasted by ENS to its analysed value. Both forecast and analysis are expressed by cumulative distribution functions. The CRPS skill score then compares CRPS of the verified forecast to a reference unskilled forecast. As a reference forecast the re-analysis-based climatology is used."

Title: Re: The 2019 melting season
Post by: Neven on April 22, 2019, 12:30:00 PM
The Uni Bremen SIC maps page (http://www.iup.uni-bremen.de:8084/amsr2/) seems to have disappeared. Does anyone know if it has been moved?
Title: Re: The 2019 melting season
Post by: oren on April 22, 2019, 12:33:33 PM
I use this link, it's still working but the images of the last 3 days appear as broken icons for some reason.

https://seaice.uni-bremen.de/databrowser/ (https://seaice.uni-bremen.de/databrowser/)
Title: Re: The 2019 melting season
Post by: gerontocrat on April 22, 2019, 12:41:56 PM
I also use https://seaice.uni-bremen.de/sea-ice-concentration/ and its working OK (Windows 10 and Google)
Title: Re: The 2019 melting season
Post by: uniquorn on April 22, 2019, 12:51:17 PM
uni-bremen smos ftp stops latest data is apr17

On a positive note, ice continues to be compacted into the triangle north west of Greenland.
Worldview terra modis apr1-21. Heavy contrast to show fractures. A faster frame rate helps to look 'through' the clouds. (11days/sec)
edit: replaced gif with mp4
Title: Re: The 2019 melting season
Post by: sark on April 22, 2019, 01:35:01 PM
Given the unreliable nature of forecasts beyond 5 days, why use them?
Why produce them?  Because they are useful
[...]
I am all for predictions, just not ten days out using unreliable tools.[...]

Since we have prediction products that extend so far into the future, but at the same time are the easiest way to show current Hour 0 conditions... I agree that some sort of notice is a necessary courtesy.  Seems simple and smart.  it's a case of implied precision.  up to hour 120 is observational talk, past hour 120 you start to blend it into model behavior talk... total respect for that.

on the other hand, making up a bunch of rules about predictions ...
Title: Re: The 2019 melting season
Post by: sark on April 22, 2019, 02:43:25 PM
I think below is a reasonable addition to the discussion.  Euro 500mb anomaly ensemble, hours 120-216.  Days 5-9.  Gif is not too big.  Illustrates something.  I think this is useful as it alerts people who might want to watch more closely in the coming days.

It is possible to post on this forum without making a bunch of prophetic predictions like WxJesus.  Nothing about this makes it necessary to list predictions.  Then again, the whole purpose of observational meteorology is to make predictions.  Let's not make this forum any less useful.
Title: Re: The 2019 melting season
Post by: Neven on April 22, 2019, 03:11:51 PM
I also use https://seaice.uni-bremen.de/sea-ice-concentration/ and its working OK (Windows 10 and Google)

But the daily SIC maps are all stuck at April 18. The archives are off-line as well. This will probably soon get fixed. If not, I'll shoot off a mail.
Title: Re: The 2019 melting season
Post by: lifeblack on April 22, 2019, 04:35:05 PM
This is from the ECMWF site:

https://confluence.ecmwf.int//display/FUG/4.1+Forecast+Error+Growth

"Small baroclinic systems or fronts are currently well forecast to around Day2, cyclonic systems to around Day4 and the long planetary waves defining weather regimes to around Day8.  As models improve over time these limits are expected to advance further ahead of the data time.  Features that are coupled to the orography (e.g. lee-troughs), or to the underlying surface (e.g. heat lows), are rather less consistently well forecast."

In this sense brr is right: although the details will change, but major weather-systems - according to ecmwf - are USUALLY forecastable for 8 days.

To check the standard deviation between the ensemble members, ie. to see how reliable the forecast is, ECMWF shows this as well with colours:

https://www.ecmwf.int/en/forecasts/charts/catalogue/plot_ensm_essential?facets=Range,Medium%20(15%20days)&time=2019042112,120,2019042612&parameter=MSLP&area=Northern%20Hemisphere

El Cid, that figure is for the overall reliability of the forecasts, correct?  Is there a separate metric for accuracy over a region from, say, 60 degrees north?  The reason I ask is because I was wondering whether the weather models might have been adjusted with some assumptions that optimize performance over populated areas at the cost of less reliability in the vicinity of the pole.
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 22, 2019, 04:44:01 PM
I like how Accuweather gives forecasts out to 90 days. Nine-tenths of this is no better than the Farmer's Almanac, but it is fun to look at anyway.
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 22, 2019, 05:03:35 PM
Blocking highs are features that the models have trouble forecasting and that's just what we're seeing now in the 120 to 240 hour forecasts. There's a major disagreement between the GFS and the ECMWF on the surface and 500mb pressure and height patterns in the Arctic. The European model is the best model, but all the models have problems with blocks.

However, I think it is helpful and useful to look at what the models are forecasting because it's information about the state of the oceans and atmosphere at any given time. I think the ECMWF forecast of developing high pressure in the Arctic is probably correct.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 22, 2019, 05:09:50 PM
I also use https://seaice.uni-bremen.de/sea-ice-concentration/ and its working OK (Windows 10 and Google)

But the daily SIC maps are all stuck at April 18. The archives are off-line as well. This will probably soon get fixed. If not, I'll shoot off a mail.
It was up to date when I looked before, and now it is not, or I am going doo lally tap even faster..
Title: Re: The 2019 melting season
Post by: bbr2314 on April 22, 2019, 08:18:27 PM
Blocking highs are features that the models have trouble forecasting and that's just what we're seeing now in the 120 to 240 hour forecasts. There's a major disagreement between the GFS and the ECMWF on the surface and 500mb pressure and height patterns in the Arctic. The European model is the best model, but all the models have problems with blocks.

However, I think it is helpful and useful to look at what the models are forecasting because it's information about the state of the oceans and atmosphere at any given time. I think the ECMWF forecast of developing high pressure in the Arctic is probably correct.
The GFS stands for good-for-sh*t  ;D

The introduction of the new FV3-GFS has been a complete disaster, they just upgraded the new version again last week which hopefully addresses some of the issues, but it is worth noting that the "GFS" is now an old model and the FV3-GFS is replacing it, with both having major problems (just FYI).

Also: the 00z EURO maintained the major cyclonic event across the PAC sector of the Arctic D7-8, although the ridging that accompanies it was slightly less amplified (the Greenland ridging became much more prominent last night). Wonder what the 12z today will show, it is running now!
Title: Re: The 2019 melting season
Post by: bbr2314 on April 22, 2019, 09:39:04 PM
The 12z EURO looks like it got worse with the overall picture even if the cyclone (now D7) is weaker vs. the same time yesterday (D8). It still rolls into the Arctic on a head of very warm weather relative to normal.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042212/ecmwf_z500_mslp_nhem_8.png)

It looks like the polar cell completely breaks down by D10 as the Greenland and NPAC blocks merge into a single entity over the CAA. Note, this is VERY far out, however, it is the first time this season we have seen such a depiction.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042212/ecmwf_z500aNorm_nhem_11.png)
Title: Re: The 2019 melting season
Post by: uniquorn on April 23, 2019, 01:18:30 AM
It also looks like the melt of the Great Slave Lake is early. Watch for an early break up of the Mackenzie
update (c to p)
Title: Re: The 2019 melting season
Post by: sark on April 23, 2019, 01:27:32 AM
It looks like the polar cell completely breaks down by D10 as the Greenland and NPAC blocks merge into a single entity over the CAA. Note, this is VERY far out, however, it is the first time this season we have seen such a depiction.

If this played out as forecast, has anyone seen anything like this before?  Recall the ridge over Alaska, then Scandinavia, and now back to Alaska in the forecast.  This is all new behavior, right?
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 23, 2019, 03:10:28 AM
Blocking highs are not something new, but their intensity and persistence in increasing. The record Greenland melt years of 2010 and 2012 were associated with strong high pressure over Greenland. Those were also bad years for the Arctic sea ice.

The coming together over the Arctic ocean of the Alaskan block and the Greenland block is particularly bad for sea ice because it creates a dipole that imports heat from the Pacific and exports ice through the Fram Strait.
Title: Re: The 2019 melting season
Post by: jdallen on April 23, 2019, 05:59:13 AM
Blocking highs are not something new, but their intensity and persistence in increasing. The record Greenland melt years of 2010 and 2012 were associated with strong high pressure over Greenland. Those were also bad years for the Arctic sea ice.

The coming together over the Arctic ocean of the Alaskan block and the Greenland block is particularly bad for sea ice because it creates a dipole that imports heat from the Pacific and exports ice through the Fram Strait.
A huge change in albedo is about to take place.

It appears that as part of the evolving conditions upwards of 1 million KM2 of snow cover in Siberia and Alaska are going to vanish in the next 5 days, as well as at least 2/3rds of the snow cover on the Chukchi and Beaufort.

This I think may qualify as "momentum".
Title: Re: The 2019 melting season
Post by: sark on April 23, 2019, 06:49:57 AM
Incredible, darkest thrill watching latest long runs of forecast products.  I want to see more.  What's the best way to read out all the daily 500mb charts for the past 15 years?  Is it  esrl.noaa?
Title: Re: The 2019 melting season
Post by: bbr2314 on April 23, 2019, 08:00:08 AM
o boy

(https://www.tropicaltidbits.com/analysis/models/gfs/2019042300/gfs_T2m_nhem_30.png)

GFS has joined the EURO party

(https://www.tropicaltidbits.com/analysis/models/gfs/2019042300/gfs_T2ma_nhem_30.png)

(https://www.tropicaltidbits.com/analysis/models/gfs/2019042300/gfs_z500aNorm_nhem_30.png)

This is by D7-8. The incursion / setup is well underway by D5-6. This would result in outright melt as well as melt ponding across a "yuge" portion of the Arctic.

The Canucks are also now in agreement!

(https://www.tropicaltidbits.com/analysis/models/gem/2019042300/gem_T2m_nhem_30.png)
Title: Re: The 2019 melting season
Post by: gerontocrat on April 23, 2019, 09:15:28 AM
o boy

GFS has joined the EURO party

This is by D7-8. The incursion / setup is well underway by D5-6. This would result in outright melt as well as melt ponding across a "yuge" portion of the Arctic.

Does posting images from GFS mean that your previous comments about GFS are no longer true?

Quote
The GFS stands for good-for-sh*t  ;D

The introduction of the new FV3-GFS has been a complete disaster, they just upgraded the new version again last week which hopefully addresses some of the issues, but it is worth noting that the "GFS" is now an old model and the FV3-GFS is replacing it, with both having major problems (just FYI).
Title: Re: The 2019 melting season
Post by: bbr2314 on April 23, 2019, 09:18:00 AM
o boy

GFS has joined the EURO party

This is by D7-8. The incursion / setup is well underway by D5-6. This would result in outright melt as well as melt ponding across a "yuge" portion of the Arctic.

Does posting images from GFS mean that your previous comments about GFS are no longer true?

Quote
The GFS stands for good-for-sh*t  ;D

The introduction of the new FV3-GFS has been a complete disaster, they just upgraded the new version again last week which hopefully addresses some of the issues, but it is worth noting that the "GFS" is now an old model and the FV3-GFS is replacing it, with both having major problems (just FYI).
No, they are still true -- individually the GFS is fairly useless, but when GFS + CMC are in agreement with the EURO, it is a sign of consensus and usually means a higher likelihood of verification. The EURO blew up the PAC ridge bigly tonight as well, although it doesn't merge the blocks quite as impressively as the 12z run did.
Title: Re: The 2019 melting season
Post by: pauldry600 on April 23, 2019, 11:26:46 AM
Uni Bremen is off for reprocessing from Apr 19 to 22

It will be back April 23
Title: Re: The 2019 melting season
Post by: Neven on April 23, 2019, 11:51:23 AM
Thanks, pauldry600!
Title: Re: The 2019 melting season
Post by: Pavel on April 23, 2019, 03:58:40 PM
Thing are getting exciting. I can't wait to see what will happen in 5-10 days. If it will be really above 0C in the half of the Central Basin during several days that could be a catastrophic scenario if we get the gray ice pack so early
Title: Re: The 2019 melting season
Post by: jai mitchell on April 23, 2019, 06:30:09 PM
o boy


The anomaly is very strong.  however, it is also paired with a huuuuuuge inflow of atmospheric water vapor which will suppress solar heating and will also produce large snow on CAB.
Title: Re: The 2019 melting season
Post by: jdallen on April 23, 2019, 07:23:30 PM
o boy


The anomaly is very strong.  however, it is also paired with a huuuuuuge inflow of atmospheric water vapor which will suppress solar heating and will also produce large snow on CAB.
Generally concur.  Biggest impact will be on the Chukchi, Beaufort and possibly the fringes of the ESS. Cloud cover will ablate effects of insulation and limit damage. The help snow will provide may be questionable and probably localized. Pacific side snowcover on the ice is forecast to drop pretty dramatically, which will lead to subsurface pooling of melt water and lowered albedo.

There will still be down-welling long wave radiation, which combined with above freezing temperatures may be problematic.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 23, 2019, 07:24:02 PM
o boy


The anomaly is very strong.  however, it is also paired with a huuuuuuge inflow of atmospheric water vapor which will suppress solar heating and will also produce large snow on CAB.
That's the question, isn't it? We have been dealing with these dueling feedbacks since 2012 it seems. However, I suspect that it will not produce large snows, but rather, rain, at least over Beaufort / Chukchi / ESS (IMO, could easily be wrong).
Title: Re: The 2019 melting season
Post by: Aluminium on April 23, 2019, 07:52:34 PM
April 14-22.
Title: Re: The 2019 melting season
Post by: Stephan on April 23, 2019, 08:47:10 PM
Just have a look at Laptev and western ESS - first breakup of sea ice from the fast ice front.
And have a look along the eastern shore of Novaja Semlja - strong SW winds open the waters again. The start of a bigger decrease in Kara Sea?
Title: Re: The 2019 melting season
Post by: bbr2314 on April 23, 2019, 09:18:00 PM
The EURO has one again upped the ante at 12z.

By D6 the setup is well underway, the low is a bit further S in the Okhotsk but ridging is more impressive over AK / Beaufort --

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042312/ecmwf_z500_mslp_nhem_7.png)

By D9 the ridging has pinched off into the high Arctic, with the merge with the Greenland block also underway.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042312/ecmwf_z500aNorm_nhem_11.png)

The medium-term solution is looking increasingly likely and increasingly warm, the D8-10 output is still variable but I do not like the trends here for retaining any real cold in the Arctic.
Title: Re: The 2019 melting season
Post by: Viggy on April 24, 2019, 12:58:24 AM
Blocking highs are not something new, but their intensity and persistence in increasing. The record Greenland melt years of 2010 and 2012 were associated with strong high pressure over Greenland. Those were also bad years for the Arctic sea ice.

The coming together over the Arctic ocean of the Alaskan block and the Greenland block is particularly bad for sea ice because it creates a dipole that imports heat from the Pacific and exports ice through the Fram Strait.

Took a few hours of staring at maps before I fully grasped what you were stating. If I understand the sequence of events that are about to unfold correctly, -
Title: Re: The 2019 melting season
Post by: Juan C. García on April 24, 2019, 03:23:07 AM
Not really on topic, but it has been discussed here.

No, they are still true -- individually the GFS is fairly useless, but when GFS + CMC are in agreement with the EURO, it is a sign of consensus and usually means a higher likelihood of verification. The EURO blew up the PAC ridge bigly tonight as well, although it doesn't merge the blocks quite as impressively as the 12z run did.

"Trump administration has EPIC plan to develop the world’s smartest weather forecasting model"
Quote
It was October 2012 when the European weather prediction model beat its American counterpart in forecasting Hurricane Sandy’s hard left turn into the U.S. coastline. What scientists had known for years — that the European forecast model was superior to the American — caught the attention of the U.S. public and Congress.
Since then, the National Oceanic and Atmospheric Administration, with funding support from Congress, has worked intensely to improve the American model. It has boosted its computing power, improved the way it brings in data, and enhanced how it simulates weather systems at small scales. Yet, more than six years later, it still trails the European model in overall accuracy.
...
As part of its 2020 budget request, to the tune of $15 million, NOAA has proposed the establishment of the Earth Prediction Innovation Center (EPIC), which it says “will advance U.S. weather modeling and reclaim international leadership in the area of numerical weather prediction.”
https://www.washingtonpost.com/weather/2019/04/23/trump-administration-has-epic-plan-develop-worlds-smartest-weather-forecasting-model/?utm_term=.27bc6a92c9ea (https://www.washingtonpost.com/weather/2019/04/23/trump-administration-has-epic-plan-develop-worlds-smartest-weather-forecasting-model/?utm_term=.27bc6a92c9ea)
Title: Re: The 2019 melting season
Post by: sark on April 24, 2019, 05:40:49 AM
is this named yet?

Days 5-12 GFS 500mb Anomaly really shows the pattern I've been seeing show up episodically all winter last year, I post this run to illustrate.  I used the graphics from https://commons.wikimedia.org/wiki/File:BuysBallot_en.svg because i couldn't figure out how to draw meshing gears
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on April 24, 2019, 06:16:28 AM
Blocking highs are not something new, but their intensity and persistence in increasing. The record Greenland melt years of 2010 and 2012 were associated with strong high pressure over Greenland. Those were also bad years for the Arctic sea ice.

The coming together over the Arctic ocean of the Alaskan block and the Greenland block is particularly bad for sea ice because it creates a dipole that imports heat from the Pacific and exports ice through the Fram Strait.
A huge change in albedo is about to take place.

It appears that as part of the evolving conditions upwards of 1 million KM2 of snow cover in Siberia and Alaska are going to vanish in the next 5 days, as well as at least 2/3rds of the snow cover on the Chukchi and Beaufort.

This I think may qualify as "momentum".

Where did you read this?  Is there a website that tracks albedo?
Title: Re: The 2019 melting season
Post by: Rodius on April 24, 2019, 06:23:39 AM
Blocking highs are not something new, but their intensity and persistence in increasing. The record Greenland melt years of 2010 and 2012 were associated with strong high pressure over Greenland. Those were also bad years for the Arctic sea ice.

The coming together over the Arctic ocean of the Alaskan block and the Greenland block is particularly bad for sea ice because it creates a dipole that imports heat from the Pacific and exports ice through the Fram Strait.
A huge change in albedo is about to take place.

It appears that as part of the evolving conditions upwards of 1 million KM2 of snow cover in Siberia and Alaska are going to vanish in the next 5 days, as well as at least 2/3rds of the snow cover on the Chukchi and Beaufort.

This I think may qualify as "momentum".

Where did you read this?  Is there a website that tracks albedo?


https://cryospherecomputing.tk/NRTawp.html
Title: Re: The 2019 melting season
Post by: Sterks on April 24, 2019, 12:20:02 PM
The weather forecast seems to settle on this torch from the Pacific starting on the weekend, has been described by others days ago.
What the EC shows in its +9 +10 days is that, as an aftermath of this atmospheric rearrangement, a strong Beaufort high would reappear, which might be pretty damning in May in case of persevering.
But this is all speculation. :-)
Title: Re: The 2019 melting season
Post by: sark on April 24, 2019, 03:01:50 PM
I am not a scientist.  I haven't even been watching very closely for an entire year, but I've been glancing at the situation in the Arctic for 20 years.  Eyes front now.

This doesn't look like a ridge, to me.  This looks like a short circuit.  The Arctic Ocean is warmer than the land.  What's happening now looks, again to an untrained eye, like the polar cell is being torn in two.

Whatever's left of cold air after this will certainly return to the Arctic in mid-May, according to pattern.  I'm hopeful more is left than appears to be in the forecast weather models.  It's uncomfortable to see GFS runs that look like mid-June of 2016 before May of 2019.

Still, the forecast temperature anomalies don't look insane.  This tormented flow pattern has somehow kept cold within 80N all winter.  I thought we'd see an ice free north pole in 2017 and that didn't happen.  Who knows, I'm just an outsider, but this has the feeling of something new & unique & damning.
Title: Re: The 2019 melting season
Post by: jai mitchell on April 24, 2019, 05:23:45 PM
o boy


The anomaly is very strong.  however, it is also paired with a huuuuuuge inflow of atmospheric water vapor which will suppress solar heating and will also produce large snow on CAB.
That's the question, isn't it? We have been dealing with these dueling feedbacks since 2012 it seems. However, I suspect that it will not produce large snows, but rather, rain, at least over Beaufort / Chukchi / ESS (IMO, could easily be wrong).

FWIW I started documenting these kinds of blocking pattern/Arctic heat and WVx inflows through the Bearing Strait in March of 2014.  See thread here:  https://forum.arctic-sea-ice.net/index.php/topic,784.msg22395.html#msg22395
Title: Re: The 2019 melting season
Post by: Jontenoy on April 24, 2019, 06:00:50 PM
Interesting graph  showing Arctic / Antarctic progress.....

https://www.carbonbrief.org/state-of-the-climate-heat-across-earths-surface-and-oceans-mark-early-2019
Title: Re: The 2019 melting season
Post by: Sterks on April 24, 2019, 06:23:07 PM
Thank you. It's good to be reminded of how screwed things are when we zoom out a bit.
This melting season no exception, and the feeling is that the 2018-2017 mini rebound is over, and if I am wrong it doesn't matter (zoom out).
And we got the orange-gutan wanting to make sure the little hopes we could have are vain.
Title: Re: The 2019 melting season
Post by: werther on April 24, 2019, 08:23:22 PM
Took a glance at Worldview today. Not my favourite medium. I used to work a lot on the Rapid response-tiles. Not available anymore. But I’m still capable to look at some spots out of 15 years of experience. Yes, still with you…
Inspired by 2 meter temps through DMI and volume projected by PIOMAS, it seemed not that bad a winter for sea ice. Worldview reveals that is mostly illusive. There are a multitude of influences at work. Just some make it to our attention. As Bering is mostly Pacific by now, sea ice in front of fast ice is crunched and mobile in East Siberian, Chukchi and Beaufort Seas, Baffin Bay ice looks vulnerable and 4 MK Central Basin is torn by long leads, things don’t look a little better at all. The big crunch didn’t happen in ’17 nor in ’18. But it can happen any year now.
Title: Re: The 2019 melting season
Post by: forkyfork on April 24, 2019, 10:11:07 PM
once again a -nao modeled days 6-10 is turning into pacific centered blocking. this has been happening since 2013. click to animate
Title: Re: The 2019 melting season
Post by: psymmo7 on April 24, 2019, 10:31:44 PM
Slightly off topic but yet another sign of arctic warming - the break up of ice on the Yukon yesterday was the second earliest ever recorded and only 8 hours behind  the earliest breakup on the same date in 2016
Title: Re: The 2019 melting season
Post by: Sebastian Jones on April 25, 2019, 02:11:04 AM
Slightly off topic but yet another sign of arctic warming - the break up of ice on the Yukon yesterday was the second earliest ever recorded and only 8 hours behind  the earliest breakup on the same date in 2016
Technically this was indeed the second earliest break up, but while the indicator ( a post is placed out on the river ice connected to a clock, when the ice moves, the post pulls a pin from the clock, which stops and records the official time of break up) showed break up, in actual fact almost all the ice is still intact. Photos of the river condition are regularly posted on the site yukonriverbreakup.com (http://yukonriverbreakup.com). This morning's pic shows the open water at the top left, where the "tripod" was. We should have another pic in an hour or so!
Title: Re: The 2019 melting season
Post by: DavidR on April 25, 2019, 02:21:24 AM
Slightly off topic but yet another sign of arctic warming - the break up of ice on the Yukon yesterday was the second earliest ever recorded and only 8 hours behind  the earliest breakup on the same date in 2016
Technically this was indeed the second earliest break up, but while the indicator ( a post is placed out on the river ice connected to a clock, when the ice moves, the post pulls a pin from the clock, which stops and records the official time of break up) showed break up, in actual fact almost all the ice is still intact. Photos of the river condition are regularly posted on the site yukonriverbreakup.com (http://yukonriverbreakup.com). This morning's pic shows the open water at the top left, where the "tripod" was. We should have another pic in an hour or so!
Of course April 23rd this year was the 113th day of the year, while April 23rd 2016 was the 114th day of the year. But who is counting, its still early.
Title: Re: The 2019 melting season
Post by: sark on April 25, 2019, 04:00:34 AM
the latest ECMWF run.  https://imgur.com/a/kXSSEUx
Title: Re: The 2019 melting season
Post by: oren on April 25, 2019, 05:04:23 AM
Took a glance at Worldview today. Not my favourite medium. I used to work a lot on the Rapid response-tiles. Not available anymore. But I’m still capable to look at some spots out of 15 years of experience. Yes, still with you…
Inspired by 2 meter temps through DMI and volume projected by PIOMAS, it seemed not that bad a winter for sea ice. Worldview reveals that is mostly illusive. There are a multitude of influences at work. Just some make it to our attention. As Bering is mostly Pacific by now, sea ice in front of fast ice is crunched and mobile in East Siberian, Chukchi and Beaufort Seas, Baffin Bay ice looks vulnerable and 4 MK Central Basin is torn by long leads, things don’t look a little better at all. The big crunch didn’t happen in ’17 nor in ’18. But it can happen any year now.
Good points. And indeed, it can happen any year now.
Title: Re: The 2019 melting season
Post by: jdallen on April 25, 2019, 06:34:17 AM
Where did you read this?  Is there a website that tracks albedo?
One of our users, Tealight has built a whole slew of marvelous tools to follow Albedo.

https://forum.arctic-sea-ice.net/index.php/topic,1749.0.html
Title: Re: The 2019 melting season
Post by: bbr2314 on April 25, 2019, 09:16:21 AM
Tonight's model consensus for D5-10:

https://www.youtube.com/watch?v=wbfgVEk-mxQ
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 25, 2019, 09:35:14 AM
This is what Bbr is talking about:
Title: Re: The 2019 melting season
Post by: Pavel on April 25, 2019, 03:00:33 PM
Melt ponds in the north Pole and whole CAB in the early May? The DMI north of 80 temperatures above 0C 6 weeks earlier than usual?
Title: Re: The 2019 melting season
Post by: Vergent on April 25, 2019, 05:04:09 PM
Where did you read this?  Is there a website that tracks albedo?
One of our users, Tealight has built a whole slew of marvelous tools to follow Albedo.

https://forum.arctic-sea-ice.net/index.php/topic,1749.0.html

You can track albedo from Topaz4 using Godiva2;

http://thredds.met.no/thredds/godiva2/godiva2.html?server=http://thredds.met.no/thredds/wms/topaz/dataset-topaz4-arc-myoceanv2-be

Last year it was based on imported data. I don't know about this year. Look for the data to jump on Mondays, that is when they import data.
Title: Re: The 2019 melting season
Post by: SimonF92 on April 25, 2019, 05:17:46 PM
Melt ponds in the north Pole and whole CAB in the early May? The DMI north of 80 temperatures above 0C 6 weeks earlier than usual?

I doubt DMI will go past 0 that soon, there is still a lot of cold kicking around
Title: Re: The 2019 melting season
Post by: uniquorn on April 25, 2019, 08:33:41 PM
JAXA RGB, jan1-apr24.
Title: Re: The 2019 melting season
Post by: uniquorn on April 25, 2019, 09:44:59 PM
Wipneus amsr2-uhh regional extent chart for bering.
https://sites.google.com/site/arcticseaicegraphs/regional
Comparison of bering/chukchi using uni-hamburg amsr2-uhh mar1-apr24 for 2018 and 2019.
Title: Re: The 2019 melting season
Post by: magnamentis on April 25, 2019, 11:07:05 PM
something tells me we're in for a nasty drop from day 2-5

what i find interesting is in how many places the ice is opening significantly despite temps around -10 and lower.

if reanalyzer forecast, not just anomaly but factual temps above zero running across the arctic and ending in the beaufort gyre we possibly see a few very early flash-melting events in the bering, chucky, as well as baffin and greenland sea. somehow for a short time most of the already weakened corners will be under attack simultaneously.

at least one can get the impression.
Title: Re: The 2019 melting season
Post by: Neven on April 25, 2019, 11:23:46 PM
Quote
something tells me we're in for a nasty drop from day 2-5

On the one hand, yes, because there will be strong winds and anomalous temps obliterating the recent increase/stall in the Bering and Chukchi Seas. On the other hand, the same massive winds will push ice towards the Barentsz and Greenland Seas.

But in the long run, this should be bad for the ice. Melt pond May is just around the corner.

Here's the latest ECMWF forecast for the coming 6 days, showing the cluster of isobars, running all the way from the Pacific and the Atlantic, pressure gradient will be around 40 hPa, which isn't bad for a dipole (but not as bad as the 60+ hPa pressure gradient in August 2016 (https://neven1.typepad.com/blog/2016/08/2016-mega-dipole.html)):
Title: Re: The 2019 melting season
Post by: Neven on April 25, 2019, 11:41:09 PM
Here's the GFS temp anomaly forecast for the coming 7 days (from Climate Reanalyzer (https://climatereanalyzer.org/wx/fcst/#gfs.arc-lea.t2anom)):
Title: Re: The 2019 melting season
Post by: magnamentis on April 25, 2019, 11:48:41 PM
Here's the GFS temp anomaly forecast for the coming 7 days (from Climate Reanalyzer (https://climatereanalyzer.org/wx/fcst/#gfs.arc-lea.t2anom)):

sorry that i was late, had both temps and anomalies almost ready

as to wind drift, yes i agree of course while that is accompanied with:

a) very strong winds

b) for the season very high temps (above zero in parts)

c) pushed into relatively warm atlantic waters where waves and heat will
.   probably give it the rest that will make the outlook for the rest of the season
.   even worse somehow and then what will happen in the greenland see where
.   it could almost vanish if the forecast is 100% accurate which i hope it's not.

what interest me is your take on the game heat+wave-action against replenishing wind-driven
new ice flushed out into the barentz ?
Title: Re: The 2019 melting season
Post by: Neven on April 26, 2019, 12:14:48 AM
what interest me is your take on the game heat+wave-action against replenishing wind-driven
new ice flushed out into the barentz ?

I'm not sure yet. Maybe, as you say, big drops. Or expansion on the Atlantic side dampens drops on the Pacific side. Of course, the expansion on the Atlantic side isn't good for the ice in the longer term, because it melts out at those lower latitudes (but maybe not right away, because it's end of April).

If this weather or similar keeps up, it should be possible for 2019 to stay close to 2016 during May. Here's the JAXA SIE graph for May:
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 26, 2019, 02:36:38 AM

what i find interesting is in how many places the ice is opening significantly despite temps around -10 and lower.


Polar amplification is caused largely by the ocean transporting heat poleward. Melt-from-below is the slow and steady that wins. Unfortunately.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 26, 2019, 03:36:17 AM
Combining 2 images - April 25th on the left, and April 21st on the right to take out cloud -  you can see the broken ice is joined together now. I looked back in the years, and don't see this any other year doing that at this time of year. 2010 comes close on May 4th. A cracked and fractured icesheet from Nares to Fram now.
 
Title: Re: The 2019 melting season
Post by: Aluminium on April 26, 2019, 06:22:57 AM
April 20-25.
Title: Re: The 2019 melting season
Post by: jdallen on April 26, 2019, 06:36:12 AM
something tells me we're in for a nasty drop from day 2-5
Actually, I'm expecting extent to stay relatively flat, possibly even expand, but concentration to drop.  Basically, the mostly the same ice except spread over a wider area.

Still not good for what's coming.
Title: Re: The 2019 melting season
Post by: uniquorn on April 26, 2019, 10:35:21 AM
Combining 2 images - April 25th on the left, and April 21st on the right to take out cloud -  you can see the broken ice is joined together now. I looked back in the years, and don't see this any other year doing that at this time of year. 2010 comes close on May 4th. A cracked and fractured icesheet from Nares to Fram now.
Agreed. edit: I should add that it is still cold enough for refreeze in those fractures, but the drift is too fast to make much difference.
Worldview terra modis, north greenland, apr8-24. Contrast enhanced to show fractures. 7days/sec.
More about nares here https://forum.arctic-sea-ice.net/index.php/topic,176.msg196830.html#msg196830
Title: Re: The 2019 melting season
Post by: Gray-Wolf on April 26, 2019, 12:11:22 PM

I'm not sure yet. Maybe, as you say, big drops. Or expansion on the Atlantic side dampens drops on the Pacific side. Of course, the expansion on the Atlantic side isn't good for the ice in the longer term, because it melts out at those lower latitudes (but maybe not right away, because it's end of April).

If this weather or similar keeps up, it should be possible for 2019 to stay close to 2016 during May. Here's the JAXA SIE graph for May:

Hi Neven!

The extension of ice into the lower lat. areas of Barentsz has not been able to occur this past winter ( and many before!) so maybe there is heat enough to begin the degradation of the ice if shunted that way?

Then we have things like swells/salinity in that area also impacting any 'stray ice' pushed out that way?

We will see 'growth' via the collapse and spread of ice entering open waters but this will be illusory.
Title: Re: The 2019 melting season
Post by: uniquorn on April 26, 2019, 01:59:26 PM
whoi ITP103-110 buoy location and temperatures, apr26.
ITP107 near the Chukchi plateau currently warmest at -3.125C
https://www.whoi.edu/page.do?pid=163096
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 26, 2019, 03:55:53 PM
2 northbound flares in the jet streams are forecast to enter the arctic in the next 4 days. The air they contain is currently over the northern pacific and the NE of the US. Apparently the main flare from the pacific will take refuge over the Beaufort sea, while the secondary system is set to head to cross Newfoundland, thru Baffin, and finally end up giving most of its energy to the primary system over Beaufort.

It is only 4 days out at this point, but still seems very open to change. I think forecasts are less stable when they are predicting multiple interacting oddities occurring at once.

If the forecast holds, it is terrible for ice. Lots of air and ocean warm from the Pacific will enter the arctic. At the same time fram and naires will see their export increase. Warmth in, ice out. Very bad.
Title: Re: The 2019 melting season
Post by: sark on April 26, 2019, 07:20:37 PM
Follow the Quadrupole
Title: Re: The 2019 melting season
Post by: binntho on April 26, 2019, 08:22:33 PM
Do you men "flares" or does "flair" have a special meteorological meaning?
Title: Re: The 2019 melting season
Post by: bbr2314 on April 27, 2019, 12:20:20 AM
2019 Big Block > 2016 Big Block

(https://www.tropicaltidbits.com/analysis/models/gfs/2019042618/gfs_z500aNorm_nhem_22.png)
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 27, 2019, 03:45:40 AM
The Beaufort is breaking up fairly north today and the system moving in should give it a real whirl. Meanwhile the exit path for the system thru the fram straight (if the 5-10 day holds) would stir the lincoln sea mightily now that the whole area has seen its fast ice reduced by 80+% (also today).

I have a feeling the laptez bite will migrate toward greenland and out the fram strait over the next 9-12 months. There is some abnormally salty water in the coastal area, and the transpolar drift has been in strong effect recently. And ice north of greenland is not providing the resistance it historically has.

What is the best way to melt the arctic? The ice floats south into the atlantic. Particularly the thicker ice. Meanwhile the Pacific spews in.
Title: Re: The 2019 melting season
Post by: Maplike on April 27, 2019, 04:36:47 AM
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?

https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Title: Re: The 2019 melting season
Post by: bbr2314 on April 27, 2019, 07:16:03 AM
00z Good-for-sh*t has 576DM ridging over Beaufort @ hr 120 :o

(https://www.tropicaltidbits.com/analysis/models/gfs/2019042700/gfs_z500aNorm_nhem_21.png)
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 27, 2019, 07:47:45 AM
00z Good-for-sh*t has 576DM ridging over Beaufort @ hr 120 :o

Thanks for your updates on this Bbr. One question though. Could you provide a little more commentary in plain language, so non-meteorologist can understand you too?
Title: Re: The 2019 melting season
Post by: Neven on April 27, 2019, 09:52:05 AM
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?

https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

We've discussed it a bit, further up-thread (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg196829.html#msg196829). Overall, I don't think the current weather set-up is good for the ice, but I'm not sure the impacts will be felt immediately.
Title: Re: The 2019 melting season
Post by: sark on April 27, 2019, 09:54:33 AM
Thanks for your updates on this Bbr. One question though. Could you provide a little more commentary in plain language, so non-meteorologist can understand you too?

Decameter.  10's of meters.  when you go up until pressure is 500 millibars, you're at about 4700-5500 meters altitude.  So the 500mb anomaly shows you decameters from average. 

Heat makes air expand.  So higher 500mb areas are warmer.  Usually the pole is cold and the air is short so hot equator air tries to flow toward it to fill in the low.  But there's a twist, the Earth spins.  So it's kind of a spiral.

Anyway, the 500mb average for that area is like +36 decameters in height or 360 meters higher than normal.  As you can see, we only are playing with about 800 meters to begin with.

They're all talking about it like it's a ridge in the jet stream but i've never before seen two giant heat domes pop up and then slam together at the north pole, cutting the polar cell in half.  But I'm no scientist.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 27, 2019, 10:00:09 AM
Thanks a lot Sark! Now even i understand it. :)
Title: Re: The 2019 melting season
Post by: bbr2314 on April 27, 2019, 10:02:05 AM
Thanks for your updates on this Bbr. One question though. Could you provide a little more commentary in plain language, so non-meteorologist can understand you too?

Decameter.  10's of meters.  when you go up until pressure is 500 millibars, you're at about 4700-5500 meters altitude.  So the 500mb anomaly shows you decameters from average. 

Heat makes air expand.  So higher 500mb areas are warmer.  Usually the pole is cold and the air is short so hot equator air tries to flow toward it to fill in the low.  But there's a twist, the Earth spins.  So it's kind of a spiral.

Anyway, the 500mb average for that area is like +36 decameters in height or 360 meters higher than normal.  As you can see, we only are playing with about 800 meters to begin with.

They're all talking about it like it's a ridge in the jet stream but i've never before seen two giant heat domes pop up and then slam together at the north pole, cutting the polar cell in half.  But I'm no scientist.
Simultaneously it is going to snow in Chicago tomorrow and the 00z EURO shows ANOTHER snow event (no stickage) for Chicago on May 5th. Tomorrow's event stands a good chance of smashing the all-time late-season (4/25+) record for Chicago (which is 3" or so).

This is all occurring as SWE is still at very high levels. Last year North America persisted while Eurasia cratered, this year, Eurasia has persisted and while NA has dropped, it is still +1SD vs. average, although hemispheric extent is closer to normal.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/nh_sce.png)

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/nh_swe.png)

The collapse of the "old regime" between 2007 and 2012 and evolution into a new state appears to be accelerating rather quickly now, and I fear for the consequences over the next few years, although they will certainly be fascinating to watch unfold.  :)

Last 365 days of temp anomalies attached below as well.
Title: Re: The 2019 melting season
Post by: gerontocrat on April 27, 2019, 11:14:15 AM
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?
There are often discussions on what might be future extreme weather events, e.g. this one due to start building up this weekend and maximising next week.

However, in the last few days conditions have not been that good for sea ice loss and this shows up in the data. i.e. sea ice extent today depends on what happened before and what is happening now, not what might happen in the future.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on April 27, 2019, 03:42:23 PM
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?
...
Welcome Maplike to the ASIF (Arctic Sea Ice Forum)!
When the Arctic weather appears to be 'bad' and extent doesn't drop, some interpret this to mean the ice is breaking up and spreading, allowing SIA (sea ice area) to decline while maintaining SIE (sea ice extent).  [For frequently used abbreviations, see Glossary (https://forum.arctic-sea-ice.net/index.php/topic,153.0.html).]
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 27, 2019, 06:08:27 PM
According to the NSIDC chart, sea ice extent has been recovering, albeit minutely, in the past couple of days. How does this gel with the weather discussion here? Does it mean anything? Should we expect to see a rapid drop in the next few days?
...
Welcome Maplike to the ASIF (Arctic Sea Ice Forum)!
When the Arctic weather appears to be 'bad' and extent doesn't drop, some interpret this to mean the ice is breaking up and spreading, allowing SIA (sea ice area) to decline while maintaining SIE (sea ice extent).  [For frequently used abbreviations, see Glossary (https://forum.arctic-sea-ice.net/index.php/topic,153.0.html).]

Could you help me understand the difference between "area" and "extent"? I thought they were the same thing...millions of square kilometers?
Title: Re: The 2019 melting season
Post by: gerontocrat on April 27, 2019, 06:17:27 PM
Could you help me understand the difference between "area" and "extent"? I thought they were the same thing...millions of square kilometers?
Read all about it...

https://cryospherecomputing.tk/doc.html  (explanation from Tealight)
Title: Re: The 2019 melting season
Post by: Tor Bejnar on April 27, 2019, 06:19:24 PM
Also, NSIDC has a page of FAQ (http://nsidc.org/arcticseaicenews/faq/)s, including area vs. extent (http://nsidc.org/arcticseaicenews/faq/#area_extent).
Title: Re: The 2019 melting season
Post by: magnamentis on April 27, 2019, 08:24:49 PM
Could you help me understand the difference between "area" and "extent"? I thought they were the same thing...millions of square kilometers?

plenty of info available here:

https://bit.ly/2Pwx2ax
Title: Re: The 2019 melting season
Post by: sark on April 28, 2019, 07:33:19 AM
Long range ensembles expect another one of these high pressure blocks to flit straight from the equator to pole at high speed, potentially colliding with the remaining high pressure block from the current mess.   From the Laptev. 

Why are these blocks coming from both sides of the planet and colliding in the Arctic?  Is that typical?
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 28, 2019, 10:48:31 AM
Why are these blocks coming from both sides of the planet and colliding in the Arctic?  Is that typical?

Formation of  a high pressure at the pole is typical. This forecast chart for 6th May shows HP centred around the pole with typical polar easterlies circulating around.

This helps to block out both Atlantic and Pacific incursions. The surface temps show a cooler ring between 70N and 80N (after the warm incursion from the Pacific has dissipated).

What would be bad for the ice is for this area of HP to slide back over the CAA and with LP over north Asia allowing another Pacific incursion. 

That said, in a few weeks we will soon be moving into high summer (June/July period) when Arctic HP can have the opposite effect on the ice and clear skies and high insolation can allow for considerable melting.
   
Title: Re: The 2019 melting season
Post by: sark on April 28, 2019, 10:19:32 PM
I see it.  I also see how much cold is being lost in the next 2 weeks.

What I'm asking specifically for is if it seems normal during the spring PV transition for high pressure to move rapidly from equator to pole without so much as half a trip around the world?  Nevermind from both East and West at the same time.  Are we okay?
Title: Re: The 2019 melting season
Post by: Niall Dollard on April 29, 2019, 01:22:44 AM
No. We are not ok. There is plenty of research out there highlighting the expansion of the hadley cells. Add to that the broadening of the Ferell cells northward and collapse of the polar.

All to be expected from the rise in global temperature.

All eyes on this summer then. Will we see another cloudy LP dominated one ? Is this the new pattern for the shrinking Arctic. Or will we see another summer period like 2012 when it all went wrong ?
Title: Re: The 2019 melting season
Post by: Slim on April 29, 2019, 02:28:51 AM
I see it.  I also see how much cold is being lost in the next 2 weeks.

What I'm asking specifically for is if it seems normal during the spring PV transition for high pressure to move rapidly from equator to pole without so much as half a trip around the world?  Nevermind from both East and West at the same time.  Are we okay?

I'm a long time lurker here, probably for more than 5 years. Just decided to post now, great forum. Just a question though from someone who is a total layman. Can cold actually be lost? When the cold air from the arctic is forced out into lower latitudes, does this actually change the equation at all or is all the heat/lack of heat in the system conserved in some way? Thanks.

<I've copied your question to this thread (https://forum.arctic-sea-ice.net/index.php/topic,143.msg197169.html#msg197169); N.>
Title: Re: The 2019 melting season
Post by: sark on April 29, 2019, 05:57:51 AM
Here's some background on the last season.  The first just shows that the Arctic warming has resulted in at least some occurrence of warm arctic, cold continents

The second is from 1948-2019, 500mb height, Feb 1 - April 25 composite mean

Third, temperatures at 1000mb, Jan 1 - April 25, 1969-2019

Finally, 500mb Anomaly, November 1 - April 25, 1960-2019
Title: Re: The 2019 melting season
Post by: wdmn on April 29, 2019, 06:12:56 AM
Thanks for posting these Sark. I find it very difficult to make much of them. There doesn't seem to be any discernible trend when presented in this form... Or am I missing something?
Title: Re: The 2019 melting season
Post by: sark on April 29, 2019, 06:42:41 AM
Thanks for posting these Sark. I find it very difficult to make much of them. There doesn't seem to be any discernible trend when presented in this form... Or am I missing something?

Pretty raw data.  After poring through them looking for patterns I think winter 2018-2019 looks like one of the cold ones.
Title: Re: The 2019 melting season
Post by: Aluminium on April 29, 2019, 06:43:56 AM
April 23-28.

The Lena wakes up on time.
Title: Re: The 2019 melting season
Post by: wdmn on April 29, 2019, 07:05:48 AM
Thanks for posting these Sark. I find it very difficult to make much of them. There doesn't seem to be any discernible trend when presented in this form... Or am I missing something?

Pretty raw data.  After poring through them looking for patterns I think winter 2018-2019 looks like one of the cold ones.

How do you connect this to your statement in your previous post that, "Arctic warming has resulted in at least some occurrence of warm arctic, cold continents"?

Is the problem that the information is presented at a scale/time frame that is useless? I wonder if looking at Jan 1 through March 15 would be more revealing?
Title: Re: The 2019 melting season
Post by: sark on April 29, 2019, 08:55:06 AM
How do you connect this to your statement in your previous post that, "Arctic warming has resulted in at least some occurrence of warm arctic, cold continents"?

Is the problem that the information is presented at a scale/time frame that is useless? I wonder if looking at Jan 1 through March 15 would be more revealing?

wdmn, here's that look...

I won't try to guess what it portends
Title: Re: The 2019 melting season
Post by: wdmn on April 29, 2019, 09:08:17 AM
Thanks a lot for doing that Sark. I was just musing, and didn't expect you to do it!

Still does not provide clarity for me either... but some recent years look like they have more pronounced differences using this time frame.
Title: Re: The 2019 melting season
Post by: sark on April 29, 2019, 09:38:40 AM
Thanks a lot for doing that Sark. I was just musing, and didn't expect you to do it!

Still does not provide clarity for me either... but some recent years look like they have more pronounced differences using this time frame.

Here's something a little more useful, perhaps.  A fun way to use this tool.  This is the 500mb anomaly running mean.  I took about a 25 day chunk of time across recent months, this is the resulting 500mb anomaly vs ESRL's climo
Title: Re: The 2019 melting season
Post by: oren on April 29, 2019, 10:04:09 AM
April 23-28.

The Lena wakes up on time.
Renewed signs of general movement from Chukchi to the Barents. This is what I fear the most, especially considering the forecasts for a dipole-like setup in the next few days. The longer the movement continues without change the thicker the ice that gets exported and lost.
Title: Re: The 2019 melting season
Post by: El Cid on April 29, 2019, 10:08:24 AM
RE: sark: warm arctic, cold continents.

As your gifs move a bit too fast, I attach mine instead: 2016-19 winters vs 1960-90. No sign of warm arctic/cold continents, instead: very warm arctic and quite warm continents.

Also: on your charts we can see that instead of a big cold airmass we are increasingly getting two smaller "poles of cold": one in Greenland/N.Canada and one in Siberia
Title: Re: The 2019 melting season
Post by: Neven on April 29, 2019, 10:41:56 AM
something tells me we're in for a nasty drop from day 2-5

Looks like you were right, JAXA reported a 112K drop for the 28th.

Renewed signs of general movement from Chukchi to the Barents. This is what I fear the most, especially considering the forecasts for a dipole-like setup in the next few days. The longer the movement continues without change the thicker the ice that gets exported and lost.

I'll second that. The high pressure over the Beaufort just keeps going, and we're now entering May...
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 29, 2019, 11:21:03 AM
I'm a long time lurker here, probably for more than 5 years. Just decided to post now

Hello and welcome Slim. :)
Title: Re: The 2019 melting season
Post by: Dharma Rupa on April 29, 2019, 12:01:39 PM
RE: sark: warm arctic, cold continents.

As your gifs move a bit too fast, I attach mine instead: 2016-19 winters vs 1960-90. No sign of warm arctic/cold continents, instead: very warm arctic and quite warm continents.

In WACC (or WACCy) the Cold is in comparison to the Warm, not to an absolute, so warm Arctic and quite warm continents is WACCy as long as the continents are warming more slowly than the Arctic.
Title: Re: The 2019 melting season
Post by: El Cid on April 29, 2019, 01:14:35 PM
RE: sark: warm arctic, cold continents.

As your gifs move a bit too fast, I attach mine instead: 2016-19 winters vs 1960-90. No sign of warm arctic/cold continents, instead: very warm arctic and quite warm continents.

In WACC (or WACCy) the Cold is in comparison to the Warm, not to an absolute, so warm Arctic and quite warm continents is WACCy as long as the continents are warming more slowly than the Arctic.

Does it really mean that? As far as I know, it means that due to Arctic winter warming, the polar jet gets "curvy" and frequent cold intrusions happen to lower latitudes, bringing sometimes bitterly cold winters, see eg here:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL069024

"Coinciding with the continued Arctic sea ice loss and Arctic amplification, cold winters and cold waves have recently been observed to be more frequent and severe over Europe, Central Asia, and the eastern United States".

I know it is a bit OT but as we move towards a more equable climate it can not happen any other way than arctic warming > midlatitude warming > equatorial warming. And this is indeed what is happening.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 29, 2019, 04:23:46 PM
Beyond the enduring polar heat of the next week or so, the next event to watch (IMO) is the +500MB pulse incoming from Central Asia in sync with the developing cyclone in the Indian Ocean (either coincident, responsible, or both for the +500MB pulse). This can be seen dominating most of northwest Siberia by D10 on the 00z EURO but I wonder if it will end up drifting into the Arctic.

The below map is +144 hours and the +500MB area is over Kazakhstan/ish here, and the Indian Ocean cyclone is also visible.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042900/ecmwf_z500_mslp_nhem_7.png)

If this heads more towards the Arctic and lingers less in Siberia, it could result in a continuation or worsening of impending conditions, and it must also be noted new +500MB blocking also appears in force in the NE PAC by D10 on the 00z EURO as well. There may only be a brief respite from the short-medium range +0C temps before many areas face similar conditions once more.
Title: Re: The 2019 melting season
Post by: magnamentis on April 29, 2019, 09:38:11 PM
if the atlantic ocean is warm enough to obliterate most of what's coming down (south) we could even see a double-century drop in one of the next 3 days. as we know most of the bering and parts of the chucky were ice-free a few weeks ago, hence it must be very poor ice there and if that's indeed the case, waves and temps around +5C could simply kill one huge chunk of ice off these days and that would make the above mentioned happen.

i generally think that the ever thinner and more fragmented ice will sooner or later lead to unprecedented fluctuations (drops) in ice extent, meaning drops of over 300'000 km2 in one day.

i'm not saying it will but i see a possibility that we shall go into uncharted "waters" in respect to melting speeds in spring as well as refreezing speeds in late fall.
Title: Re: The 2019 melting season
Post by: uniquorn on April 29, 2019, 10:46:00 PM
Attempting here to locate the least mobile ice by highlighting those areas with the least change detected by ascat.
top left: ascat (contrast enhanced) day 68-118
top right: interferometry applied by creating frames of (R,G.B) = (dayn - dayn-1, dayn - dayn-2, dayn - dayn-3)
bottom left: edge detect applied to interferometry
bottom right: heavy contrast applied to edge detect to highlight least mobile areas.

edit:last chance to vote in the 'ice edge at minimum poll'
https://forum.arctic-sea-ice.net/index.php/topic,2632.msg194424.html#msg194424

Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 29, 2019, 10:55:44 PM
The sparrowhawk forming.
Title: Re: The 2019 melting season
Post by: Tom_Mazanec on April 29, 2019, 11:25:36 PM
What's a 'sparrowhawk'?
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 29, 2019, 11:36:02 PM

i generally think that the ever thinner and more fragmented ice will sooner or later lead to unprecedented fluctuations (drops) in ice extent, meaning drops of over 300'000 km2 in one day.


IMO this does seem likely. There have been many areas of mobile ice over the last month which has seen the open water freeze. The ice there is naturally very very thin.

As the insolation balance crosses the threshold in the next few weeks, the laptev sea could see this occur at a pretty large scale. It could also happen to a lesser degee in the beaufort and chukchi.

Meanwhile, the barents sea ice has been drifted south about 80 km in the past week. This has temporarily lead to increases in the seas extent and area, but this short term increase in ice will lead to a medium term decrease. The month of May will likely sea the barents go from 500k to 0k.


In general the ice is much more mobile than "ever" before. Other than fast ice around the edges of the arctic ocean, the only serious area of ice that seems able to stack up faster than it exports/melts is in the triangle north of the CAA and Greenland. This ice is found from Price Patrick to the North Pole to the northern tip of Greenland. Everything other than that is thin, weak, and mobile.
Title: Re: The 2019 melting season
Post by: interstitial on April 30, 2019, 01:31:45 AM
What's a 'sparrowhawk'?
In the ice edge at minimum topic they drew lines around what shape the remaining ice would take. some vaguely look like animals.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on April 30, 2019, 01:46:36 AM
What's a 'sparrowhawk'?
In the ice edge at minimum topic they drew lines around what shape the remaining ice would take. some vaguely look like animals.

I think it will look like a penguin.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on April 30, 2019, 07:25:51 AM
What's a 'sparrowhawk'?

For reference:

My pessimism in a picture.

Green (sparrowhawk) line.
Title: Re: The 2019 melting season
Post by: Neven on April 30, 2019, 09:31:05 AM
The massive shift towards the Atlantic continues for at least another week. Extent in the Barentsz has gone up a bit, unlike the Greenland Sea, but there's a limit to that compensation, as we're already witnessing, especially at this time of year. I also wonder whether that cyclone right over the Kara Sea in the next three days will have a marked effect on the sea ice there.

Right now, the big drops are obviously caused by Okhotsk, Bering and Chukchi, and it's just a matter of time when the Beaufort is going to join the party. It already looks like there's quite a bit of open water along the coast and between floes, but under a camouflage of fog/thin ice, keeping the trend line on the UH AMSR2 graph steady, whereas in 2016 the trend line had already started dropping.

A the bottom, there's an animation showing the situation on May 7th 2016 (a week from today) versus yesterday. Given the current forecast things should look a lot more similar next week.
Title: Re: The 2019 melting season
Post by: FishOutofWater on April 30, 2019, 02:17:25 PM
This image does not show warm arctic cold continents. Excellent image, Sark.

It shows something far more important. It shows the impingement of warm Atlantic and Pacific water into the Arctic and the increasing amounts of ocean heat that are entering the Arctic atmosphere from the Arctic ocean itself as the ice thins. The cold weather persists where thick ice piles up north of the CAA and northern Canada is still cold. Even Siberia is being warmed by the Atlantification of the Siberian side of the Arctic.

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2591.0;attach=119432;image)

Graphics for the 500mb heights and ice thickness would be best done for exactly the same time periods to visualize the relationships between retreating and thinning ice, surface temperatures, and changes in atmospheric circulation patterns. In the post above, the comparisons are apples vs oranges.

It's very clear to me that there has been a large increase in heat transfer from the Arctic ocean water to the atmosphere. We will reach a planetary tipping point when there's so little ice that winter cloudiness cuts total radiative heat loss from the Arctic. Then we can expect really weird things, perhaps like super polar lows in midwinter along the shores of Siberia.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 30, 2019, 03:23:29 PM
This image does not show warm arctic cold continents. Excellent image, Sark.

It shows something far more important. It shows the impingement of warm Atlantic and Pacific water into the Arctic and the increasing amounts of ocean heat that are entering the Arctic atmosphere from the Arctic ocean itself as the ice thins. The cold weather persists where thick ice piles up north of the CAA and northern Canada is still cold. Even Siberia is being warmed by the Atlantification of the Siberian side of the Arctic.

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2591.0;attach=119432;image)

Graphics for the 500mb heights and ice thickness would be best done for exactly the same time periods to visualize the relationships between retreating and thinning ice, surface temperatures, and changes in atmospheric circulation patterns. In the post above, the comparisons are apples vs oranges.

It's very clear to me that there has been a large increase in heat transfer from the Arctic ocean water to the atmosphere. We will reach a planetary tipping point when there's so little ice that winter cloudiness cuts total radiative heat loss from the Arctic. Then we can expect really weird things, perhaps like super polar lows in midwinter along the shores of Siberia.
They will increasingly begin to appear everywhere (and particularly during fall and spring), IMO.
Title: Re: The 2019 melting season
Post by: bbr2314 on April 30, 2019, 03:32:19 PM
The +500MB intrusion from the Indian Ocean cyclone is now unanimously entering the Arctic at D10 across all modeling (via the Kara). It is obviously D10 but this is a larger atmospheric event and probably has a bit more certainty than normal (like our current warm intrusion). Most importantly, the key ingredient is already fully-formed and on the table (the cyclone).

(https://www.tropicaltidbits.com/analysis/models/gfs/2019043006/gfs_z500aNorm_nhem_41.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019043000/ecmwf_z500aNorm_nhem_11.png)

(https://www.tropicaltidbits.com/analysis/models/gem/2019043000/gem_z500aNorm_nhem_41.png)

We will barely have a respite between the current episode and the impending movement of ^ into the High Arctic.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on April 30, 2019, 05:02:32 PM
Why are these blocks coming from both sides of the planet and colliding in the Arctic?  Is that typical?
Check out the jetstream at 500 or 250hPa spinning up those high pressures are ground level. The atmosphere is always trying to reach equilibrium. If it ever does settle down, a more normalised (less wavy) jetstream will likely settle in further north than usual.
That's my uneducated guess anyway.

https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-84.35,77.67,619/loc=144.764,86.131
Title: Re: The 2019 melting season
Post by: El Cid on April 30, 2019, 06:39:58 PM
This image does not show warm arctic cold continents. Excellent image, Sark.

It shows something far more important. It shows the impingement of warm Atlantic and Pacific water into the Arctic and the increasing amounts of ocean heat that are entering the Arctic atmosphere from the Arctic ocean itself as the ice thins. The cold weather persists where thick ice piles up north of the CAA and northern Canada is still cold. Even Siberia is being warmed by the Atlantification of the Siberian side of the Arctic.

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2591.0;attach=119432;image)

...Then we can expect really weird things, perhaps like super polar lows in midwinter along the shores of Siberia.

It seems that the final pole of cold is going to be the Greenland/N.Canada region. And I also believe that with an ever more open/cloudy Arctic Sea, the North will be ruled by a big low pressure system even during the winter (or at least Nov/Dec before it freezes over). Question is: how it would change atmospheric circulation in the midlatitudes? Any guesses?
Title: Re: The 2019 melting season
Post by: Ice Shieldz on April 30, 2019, 09:06:32 PM
Well a bit off topic but as far as WACC is concerned, it's primarily Eurasia that's been the champion of the cold continent phenomena, fueled in part by increasing snow - which is to be expected in a warming climate.

The WACC phenomena with Eurasia as the focus may be short lived and it could be that we are seeing the more likely longer-term outcome begin to show itself. As sea ice significantly vanishes, the huge block of ice that is Greenland becomes a more enduring sink to anchor arctic cold closer to north american region. If so, then the jet becomes more prominently driven by the increased temp/pressure differential between surrounding warmer air and Greenland (including CAA). All of this would of course lead to more frequent splitting and/or degradation of the polar cell.
Title: Re: The 2019 melting season
Post by: uniquorn on April 30, 2019, 09:51:57 PM
On the ice measurements from whoi itp103-110.
itp107 closest to Chukchi latest reading -0.625C   https://www.whoi.edu/page.do?pid=163096
Title: Re: The 2019 melting season
Post by: Greenbelt on May 01, 2019, 03:04:37 AM
This was ECMWF's forecast for tomorrow from 7 days ago.  Pretty similar to the setup we're actually expecting tomorrow, with strong high pressure from the Beaufort coast to Greenland, and low pressure in the Kara Sea area. I know the models are often wrong, but they are also often right, at least out 7 days.
(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019042312/ecmwf_z500_mslp_nhem_9.png)
Title: Re: The 2019 melting season
Post by: Rod on May 01, 2019, 05:45:07 AM
The NASA Worldview images are stunning today (4/30/19). I don't think I have ever seen such clear skies over so much of the arctic on the same day this early in the season. 

PSA, if you don't keep a close eye on worldview, make sure to check it out today.  You can see the effects of the weather that everyone is talking about.  It is still very early in the season and things can change a lot!  But, right now the ice looks to be in trouble in many spots. 

Bbr is predicting a cyclone will come up through the Kara in a few days.  That happened last year about this time and it seemed to help the ice and change the direction of the melt season.  If it happens now, with the current state of the ice, the results might be different. 
Title: Re: The 2019 melting season
Post by: BenB on May 01, 2019, 10:43:42 AM
This image is based on yesterday's Modis image with bands 7-2-1 overlayed with the daytime ice surface temperature using a compressed palette. Yellow has been calibrated to around 273 K (with orange-red being warmer), so the idea is to an alternative indication of where surface melt is likely:
Title: Re: The 2019 melting season
Post by: be cause on May 01, 2019, 11:10:52 AM
This image is based on yesterday's Modis image with bands 7-2-1 overlayed with the daytime ice surface temperature using a compressed palette. Yellow has been calibrated to around 273 K (with orange-red being warmer), so the idea is to an alternative indication of where surface melt is likely:


.. does deep purple mean smoke on the water ? :) .. b.c.

 seriously though .. this is a useful image .. and gerontocat may appreciate another way of seeing Greenland burn ..
Title: Re: The 2019 melting season
Post by: uniquorn on May 01, 2019, 12:26:00 PM
This image is based on yesterday's Modis image with bands 7-2-1 overlayed with the daytime ice surface temperature using a compressed palette. Yellow has been calibrated to around 273 K (with orange-red being warmer), so the idea is to an alternative indication of where surface melt is likely:
Thanks for this, useful in areas where there are no clouds.
Title: Re: The 2019 melting season
Post by: JayW on May 01, 2019, 12:28:51 PM
One week (~174 hours) movie, Pacific side.
Title: Re: The 2019 melting season
Post by: BenB on May 01, 2019, 12:42:16 PM
This image is based on yesterday's Modis image with bands 7-2-1 overlayed with the daytime ice surface temperature using a compressed palette. Yellow has been calibrated to around 273 K (with orange-red being warmer), so the idea is to an alternative indication of where surface melt is likely:
Thanks for this, useful in areas where there are no clouds.

In case there is any doubt, only the white areas are clouds. Light blue is ice at surface temperatures outside the compressed palette. Generally below around 268 K. They could in theory be above the highest temperature shown by the palette, but I set it to make sure that wouldn't be a (significant) issue.
Title: Re: The 2019 melting season
Post by: Sterks on May 01, 2019, 03:38:01 PM
NH snow extent has broken the negative tendency, Rutgers maps show now positive anomalies in vast extents of Western and Southern Russia.
Thin cover, may melt fast, but this is positive for the melting season if it shows persistence in May.
Title: Re: The 2019 melting season
Post by: Sterks on May 01, 2019, 04:23:03 PM
Right now, the big drops are obviously caused by Okhotsk, Bering and Chukchi, and it's just a matter of time when the Beaufort is going to join the party. It already looks like there's quite a bit of open water along the coast and between floes, but under a camouflage of fog/thin ice, keeping the trend line on the UH AMSR2 graph steady, whereas in 2016 the trend line had already started dropping.
Yep, Beaufort extent is going to take a dip this very first week of May, and EC forecast of today makes the wind pattern away from the coast more persistent, almost until the 11th if we trusted that long range forecast.
Title: Re: The 2019 melting season
Post by: magnamentis on May 01, 2019, 07:51:26 PM
Yep, Beaufort extent is going to take a dip this very first week of May, and EC forecast of today makes the wind pattern away from the coast more persistent, almost until the 11th if we trusted that long range forecast.

and this time big parts won't re-freeze and open water at the edges (coasts) of the arctic oceans will definitely take in some insolation in serious.
Title: Re: The 2019 melting season
Post by: Sterks on May 01, 2019, 09:04:27 PM
The ice being flushed seems pretty thick, is breaking in quite big blocks before dissolving west of Svalbard.
Title: Re: The 2019 melting season
Post by: magnamentis on May 01, 2019, 09:56:35 PM
since i rarely see anything of this kind posted here i thought i bring to your attention
this great source where one can get the best overall impression about the state of the ice.
getting close to satellite photos with zero cloud scenarios, while of course it is not.

the screenshot shows not the full potential/size and any date can be chosen to compare
between years or any other time frame.

link to site:

https://kuroshio.eorc.jaxa.jp/JASMES/daily/polar/index.html?date=&prod=SIC&area=NP&sensor=MOD

of course there is an antarctic selection as well as many other parameters to choose from.
since some of you like to post images on a regular basis, choose size and area shown very
carefully, this might be something for you.
Title: Re: The 2019 melting season
Post by: vox_mundi on May 01, 2019, 10:54:33 PM
Re: https://forum.arctic-sea-ice.net/index.php/topic,2591.msg197532.html#msg197532

Thanks magnamentis. That's a very useful site.
Title: Re: The 2019 melting season
Post by: FlyOnTheWall on May 02, 2019, 02:59:09 AM
Hi All,
I'm a longtime lurker, first time poster. Does anyone know why the climatereanalyzer site is unavailable? And when it may be available again? (Sorry if this isn't the right thread for such a question.)
Thanks!

<Answer is here (https://forum.arctic-sea-ice.net/index.php/topic,2533.msg197495.html#msg197495); N.>
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 02, 2019, 05:41:02 AM
Cool site Magnamentis. Thanks for the link.
Title: Re: The 2019 melting season
Post by: Aluminium on May 02, 2019, 07:18:29 AM
April 26 - May 1.
Title: Re: The 2019 melting season
Post by: oren on May 02, 2019, 08:55:06 AM
Welcome, FlyOnTheWall. The first post is the hardest...
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 02, 2019, 08:57:09 AM
Hi All,
I'm a longtime lurker, first time poster.
Hello and welcome FlyOnTheWall. :)
Title: Re: The 2019 melting season
Post by: interstitial on May 02, 2019, 10:25:13 AM
welcome Fly On The Wall.  8)
On another thread, 2019 sea ice area and extent data reply 681, it was reported, by Gerontocrat, that they were having problems with their cloud provider and no word on when the problem will be resolved. :(
Title: Re: The 2019 melting season
Post by: Niall Dollard on May 02, 2019, 06:41:53 PM
The recent clear out of cold from the Pacific side over to the Atlantic has resulted in Longyearbyen in Svalbard recording a below normal daily mean (-9.2 C) on May 1st. This is the first below normal daily mean there since March 16th.

Persistent northerlies has meant the pack is pushed against the north coast of island of Spizbergen - something that hasnt happened since July 2017.

Nevertheless April 2019 was another very mild month in Svalbard  - with no below "normal" day at Longyearbyen.

The climate is changing so fast in Svalbard they will have to come up with new ways of defining what "normality" is. 15 year norm periods ?  :o
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 03, 2019, 04:18:57 AM
May 2nd, Pacific heat entering the Arctic
Title: Re: The 2019 melting season
Post by: jdallen on May 03, 2019, 06:33:37 AM
<snippage>
Persistent northerlies has meant the pack is pushed against the north coast of island of Spizbergen - something that hasnt happened since July 2017.
It appears Fram export is ramping up in tandem with this.  Just the last few days it appears the ice has been accelerating through it.  The northerlies no doubt are contributing to this.

Velocities appear to be approaching 1-1.5KPH.  At current concentrations, that's upwards of 10,000KM2 a day of the thickest ice in the region past the point of no return.
Title: Re: The 2019 melting season
Post by: uniquorn on May 03, 2019, 11:19:41 AM
On the ice temperatures from the whoi itp bouys 104-110. Interesting that they indicate slightly warmer temperatures than nullschool today. (I rarely compare them)
Both 107 and 110 briefly >0C recently   https://www.whoi.edu/page.do?pid=163096
itp103 hasn't reported since apr30 :(
Title: Re: The 2019 melting season
Post by: gerontocrat on May 03, 2019, 11:46:14 AM
<snippage>
Persistent northerlies has meant the pack is pushed against the north coast of island of Spizbergen - something that hasnt happened since July 2017.
It appears Fram export is ramping up in tandem with this.  Just the last few days it appears the ice has been accelerating through it.  The northerlies no doubt are contributing to this.

Velocities appear to be approaching 1-1.5KPH.  At current concentrations, that's upwards of 10,000KM2 a day of the thickest ice in the region past the point of no return.
Those "persistent northerlies" started out as "persistent southerlies" from the North Pacific.
A lot of ice heading south into the Atlantic killing zone?

Northerlies will gradually reduce in strength over the next few days according to weatherforecast.com
Title: Re: The 2019 melting season
Post by: uniquorn on May 03, 2019, 06:39:27 PM
A comparison of 2019 and 2016 using uni-hamburg amsr2-uhh apr1-may2.
Title: Re: The 2019 melting season
Post by: oren on May 03, 2019, 07:40:53 PM
Thank you uniquorn.
The Beaufort was crazy in 2016.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 04, 2019, 04:04:55 AM
Thank you uniquorn.

Could agree more.

The Beaufort was crazy in 2016.

Beaufort is just getting its spin on now. It is soon to almost similarish to 2016. Albeit seriously less separation, BUT with a much deeper cut into the fast ice between Banks Island and the continent (what is that channel called?).
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 04, 2019, 04:27:02 AM
Barents ice has been push south about 100 km in the last 2 weeks. In May it will see a sudden and epic 300k+ drop.
Title: Re: The 2019 melting season
Post by: sark on May 04, 2019, 09:05:34 AM
https://www.aer.com/science-research/climate-weather/arctic-oscillation/


What is even happening?
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 04, 2019, 09:49:51 AM
https://www.aer.com/science-research/climate-weather/arctic-oscillation/


What is even happening?
Looks like the Arctic High pressure area is re-establishing itself and normal, but a bit warmer, service of weather with the western (ZONAL) winds and episodic associated fronts might again start in the temperate NH instead of latitudinal (F... always getting these the wrong way... MERIDIONAL) north-south winds. Of course this is happening when arctic is getting much sunlight, so the Arctic cloudiness of later summer, that we've gotten used to in recent post-2012 years is likely to reappear once we hit the highest insolation days in about a month. Did the Pacific burst of warmish air clear the supply of cold air for longer period? The North European spring/early summer may continue soonish. It's hard to decide what to want, are the prolonged periods of weather of the same type good or would we prefer a more changing weather be it bad or fair? The latter might be coming for a bit, imho. (Hopefully vague enough, weather is a difficult subject)
Title: Re: The 2019 melting season
Post by: Gray-Wolf on May 04, 2019, 04:53:36 PM
I hope we all remember that after 2007 Serreze looked at 'perfect melt storms' of export and melt for any 'cycle' and found a ten to twenty year return period for the synoptic.

The two prior to 07' showed a 10 year return period.

Since 2017 we have been in the 'return period' for such an event so the sight of HP dominance and strong di-pole has me a tad twitchy!

Have we altered atmospheric patterns to the point that the 'perfect melt storm' synoptic no longer exists or are we seeing the basin settle into the patterns needed for it to return?

I have maintained,for over a decade now,that such a return would be one way for us to see the B.O.E. appear early (before it becomes a norm) is it this year?
Title: Re: The 2019 melting season
Post by: gerontocrat on May 04, 2019, 09:34:03 PM
Warmth and yet more warmth is coming into Baffin Bay and beyond from now. Attached is a map of the daily max temps on 8th May, which looks like persisting.

I am not sure if I have seen such a map so early in the season that looks like being so persistent.
Title: Re: The 2019 melting season
Post by: sark on May 04, 2019, 10:34:42 PM
bears repeating: https://www.aer.com/science-research/climate-weather/arctic-oscillation/

Quote
Final Warmings are not my expertise, but I am surprised to observe what appears to be very robust troposphere-stratosphere-troposphere coupling so late in the season and for it to apparently have the classic tropospheric signature of Greenland blocking and cold temperatures both in Europe and North America.  Though it does seem that such an event is not unprecedented.  I thank @nitzancohen for pointing out to me that something similar occurred in May 1997.  I include the PCHs for all of 1997 (Figure ii) and I was surprised to see that the most impressing warming of the stratospheric PCHs for that entire year took place in May.  The warm/positive PCHs in the lower troposphere lasted for about a month from early May until early June.  Observed temperature anomalies from May 5 through June 5, 1997 shows below normal temperatures in eastern North America and Northern Europe for that period (Figure iii).

The below figure is Dr Judah Cohen's charted GFS forecast for polar cap height (GPH anomaly)

Again.  What is even happening?
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 04, 2019, 11:23:07 PM
bears repeating: https://www.aer.com/science-research/climate-weather/arctic-oscillation/

Quote
Final Warmings are not my expertise, but I am surprised to observe what appears to be very robust troposphere-stratosphere-troposphere coupling so late in the season and for it to apparently have the classic tropospheric signature of Greenland blocking and cold temperatures both in Europe and North America.  Though it does seem that such an event is not unprecedented.  I thank @nitzancohen for pointing out to me that something similar occurred in May 1997.  I include the PCHs for all of 1997 (Figure ii) and I was surprised to see that the most impressing warming of the stratospheric PCHs for that entire year took place in May.  The warm/positive PCHs in the lower troposphere lasted for about a month from early May until early June.  Observed temperature anomalies from May 5 through June 5, 1997 shows below normal temperatures in eastern North America and Northern Europe for that period (Figure iii).

The below figure is Dr Judah Cohen's charted GFS forecast for polar cap height (GPH anomaly)

Again.  What is even happening?

Can you break this down Barney Style for newbs like me?
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 05, 2019, 12:10:48 AM
What apparently is happening is that greenhouse gases are speeding up the Brewer Dobson circulation - the flow of air from the troposphere to the stratosphere and back. In this case is is causing subsidence over Greenland, the Beaufort sea and the high Arctic. This is why, barring the lucky occurrence of cool cloudy stormy July, I think we are likely to see a new record sea ice minimum this September.

https://acomstaff.acom.ucar.edu/randel/Garcia_Randel_JAS.pdf

As Cohen wrote in his blog post, this subsidence tends to persist. A very warm sunny May maximizes the input of solar heat early, potentially allowing for a high amount of feedback due to reduced albedo in response to low early snow and sea ice extents.

These stratospheric processes may have a large impact on September sea ice extent, area and volume. Depending on the index, Greenland has had the 2nd earliest or earliest early melting and the western side of Greenland had little snow in the winter so it will rapidly darken when the west side has surface melting.

The stratospheric events of the past 6 months have been a real shocker. I think the high pressure over Greenland and the western Arctic will likely continue into June.

Below is an earth.nullschool.net image of the lower stratospheric temperature and circulation at 17Z 4May19. It shows warm air sinking over the pole. That subsidence continues into the troposphere.
Title: Re: The 2019 melting season
Post by: sark on May 05, 2019, 01:24:26 AM
https://www.youtube.com/watch?v=6HYRz8mwqkE
Title: Re: The 2019 melting season
Post by: echoughton on May 05, 2019, 03:23:17 AM
https://www.aer.com/science-research/climate-weather/arctic-oscillation/


What is even happening?
Title: Re: The 2019 melting season
Post by: echoughton on May 05, 2019, 03:25:33 AM
PLEASE make note of that date..May 13...and retrieve in 9 days and see how ridiculous posted 9 day guesses are. Really getting tiresome. Those long range models are rarely even in the ball-park, let alone verify.
Title: Re: The 2019 melting season
Post by: Niall Dollard on May 05, 2019, 03:27:53 AM
What apparently is happening.....


At this stage I will remind you  Foow of  a pronouncement you made  in another thread early in the year of a cold winter for western Europe. (Based on Sudden SW). It did not happen..

Title: Re: The 2019 melting season
Post by: sark on May 05, 2019, 04:14:26 AM
Why bother
Title: Re: The 2019 melting season
Post by: Aluminium on May 05, 2019, 07:50:55 AM
April 29 - May 4.
Title: Re: The 2019 melting season
Post by: El Cid on May 05, 2019, 09:08:09 AM
A very warm sunny May maximizes the input of solar heat early, potentially allowing for a high amount of feedback due to reduced albedo in response to low early snow and sea ice extents.

I tend to agree, but does anyone have a chart showing May (pressure over the Arctic? cloudiness? etc?) vs later melt?
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 05, 2019, 05:18:54 PM
We had very cold weather in the north central U.S. after Jan 15 this year as I forecast. Long range forecasts are notoriously hard to get better than climatology. The one I made before Christmas and posted elsewhere was about as good as those kinds of forecasts get. You got no "beast from the east" in Europe following the late December SSW but the north central and north eastern U.S. was brutalized by polar air.

Here's what happened in late spring early summer 1997, perhaps an analogous year to this one.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 05, 2019, 05:22:54 PM
Thanks, FishOutofWater for your insights. I for one appreciate them.
Title: Re: The 2019 melting season
Post by: be cause on May 05, 2019, 07:00:10 PM
Thanks, FishOutofWater for your insights. I for one appreciate them.

  + 1 .. probably + 100's .. :)

  b.c.
Title: Re: The 2019 melting season
Post by: Sterks on May 05, 2019, 09:31:31 PM
Occasional over freezing temps may have caused some wetting of the ice off Alaskan coasts, not much, nothing near Canada, but note the shift toward red in the upper part of this MODIS 3-6-7 corrected reflectance image. This agrees with report from buoys, brought by Uniquorn.
Near Bering even the 7-2-1 images showed darkening blue as expected after the wave, and that means some ponds, this was evident especially near the edge. Today is overcast over there.
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 06, 2019, 04:57:51 AM
April 29 - May 4.

Beaufort looks like it is in baaaaaaaad shape.
Title: Re: The 2019 melting season
Post by: sark on May 06, 2019, 08:29:08 AM
Yeah and it will suffer a heat wave right over the Beauforts area, above zero temps with high pressure in 15-20 days.  I guarantee it.

Ask me how I know
Title: Re: The 2019 melting season
Post by: Rodius on May 06, 2019, 09:58:40 AM
Yeah and it will suffer a heat wave right over the Beauforts area, above zero temps with high pressure in 15-20 days.  I guarantee it.

Ask me how I know

How do you know?
Title: Re: The 2019 melting season
Post by: El Cid on May 06, 2019, 10:19:00 AM
I guaranteed forecast for 15-20 days! Truly amazing, an unmatched feat so far by even the  best computer models.

So I beg you answer:

How do yo know?
Title: Re: The 2019 melting season
Post by: meddoc on May 06, 2019, 11:15:36 AM
In 15- 20 Days Melting begins, so 0 °C Temps will be pretty much common everywhere in the Arctic.

Genius.
Title: Re: The 2019 melting season
Post by: Sterks on May 06, 2019, 12:02:55 PM
LOL
In fact CFS (long range) predictions in two weeks and for June show this Beaufort anomaly and pretty much Arctic wide surface melt.
But I don't trust CFS much less when surface melt starts, and I dont want to be eaten up by the forum so I dont bring it about, and anyway you can check it at tropicaltidbits.com

But yeah, I love Meddoc response (only that surface melting onset sometimes is delayed by weeks... but doesnt seem it will be really late this year does it?).
Title: Re: The 2019 melting season
Post by: uniquorn on May 06, 2019, 12:32:53 PM
I like the long range forecasts. The melting season threads have always been full of them (as far back as I've gone). I would like them a lot more, and learn more, if the OP posted reanalysis on them 10days later. or20d ;)
Title: Re: The 2019 melting season
Post by: Sterks on May 06, 2019, 02:40:06 PM
I like them too but not between May and November... Or so. The CFS in particular, I don't know what it makes of the melting ice, but something goes very wrong in Summer.
Title: Re: The 2019 melting season
Post by: Archimid on May 06, 2019, 02:59:18 PM
I don't like them, specially as they seem to crop up more often than present or historic data. This creates a subconscious bias towards imaginary Arctic set ups.

I understand forecasts can sometimes be insightful, and I like that part, but I think it is being overdone. I like Uniquorn's comments, maybe an etiquette can be created were anyone that posts a forecast owes the thread the actual resolution of that forecast.
Title: Re: The 2019 melting season
Post by: Stephan on May 06, 2019, 06:55:38 PM
I also recommend a re-vision of long-term forecasts to prove whether they have become true. And - if possible - an analysis why they haven't become true if this is the case.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 06, 2019, 07:54:16 PM
I would propose a 'Long Term Weather Forcast Thread'.

There are obviously people not interested in this kind of content. By having it in a separate thread they could easily avoid it. And the ones interested wouldn't feel restricted and could post freely.
Title: Re: The 2019 melting season
Post by: Shared Humanity on May 06, 2019, 08:40:21 PM
Weather forecasts are certainly appropriate for this melting season thread. How can we discuss the season otherwise. I agree that if someone posts a long term forecast, they should be responsible for providing an update as to the accuracy of the original forecast.
Title: Re: The 2019 melting season
Post by: Alphabet Hotel on May 06, 2019, 09:08:25 PM
It should be easy to analyze how well forecasts pan out. If you download all the images from Climate Reanalyzer every time the model updates and tag them with the model run date/time and the valid date/time, after collecting enough images you can animate how the forecast for one date evolved. You just take one image from each model run and animate from oldest to newest. For example with the 81 frames from the GFS animation, you would take frame 81 from the first run, frame 80 from the second run, etc. The images are small and there are only 324 per day in this case.
Title: Re: The 2019 melting season
Post by: epiphyte on May 07, 2019, 05:57:19 AM
I can firmly predict that many of the predictions, whether informed, uninformed, sophisticated, scientific, heuristic, statistical, intuitive, mystical, or just flat-out clueless, for the arctic weather in mid-May, ten days from now, will be wrong. Some of them will also come close to the truth.

The thing that I find fascinating about this subject is that there's no readily apparent correlation between the amount of money, science, expertise, and technological awesomeness that goes into such predictions and their eventual accuracy.
Title: Re: The 2019 melting season
Post by: Eco-Author on May 07, 2019, 12:12:36 PM
GLOBAL Ice - well below the line. 
Title: Re: The 2019 melting season
Post by: SimonF92 on May 07, 2019, 01:00:41 PM
3 incorrect predictions and then the user gets a warning label stuck over their username for all to see?
Title: Re: The 2019 melting season
Post by: SimonF92 on May 07, 2019, 01:07:03 PM
Back on topic;

JAXA extent continues to track with 2016 (a bad year indeed), yet the FDD implies the ice is actually in pretty good shape and is similar to 2013 (one of the best years of the decade)?
Title: Re: The 2019 melting season
Post by: gerontocrat on May 07, 2019, 01:30:41 PM
Back on topic;

JAXA extent continues to track with 2016 (a bad year indeed), yet the FDD implies the ice is actually in pretty good shape and is similar to 2013 (one of the best years of the decade)?
FDD uses the DMI North of 80o temperature, which is a small fraction of the area of the Arctic. Not only that, the way DMI calculates the temperature (giving equal weight by latitude, not by area) bends the data towards the pole. I wonder what the correlation is between FDD and maximum extent and / or area.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 07, 2019, 01:33:02 PM
FDD might not be a good measure to derive the shape of the ice?
Title: Re: The 2019 melting season
Post by: Neven on May 07, 2019, 01:33:40 PM
Back on topic;

JAXA extent continues to track with 2016 (a bad year indeed), yet the FDD implies the ice is actually in pretty good shape and is similar to 2013 (one of the best years of the decade)?

Yes, but 80N isn't all of the Arctic, and there are other influences besides temperature. However, in all fairness, I've been assuming that the past winter has been relatively good for ice. I'm not so sure anymore.
Title: Re: The 2019 melting season
Post by: be cause on May 07, 2019, 01:34:53 PM
Back on topic;

JAXA extent continues to track with 2016 (a bad year indeed), yet the FDD implies the ice is actually in pretty good shape and is similar to 2013 (one of the best years of the decade)?

this is why , although interesting , area north of 80' is far from the whole of the Arctic . This year cold dominated near the pole while the ice it was cooling has been headed for Fram and Nares .
  All the ice that was between the pole and Fram at the start of the freezing season has already exited stage right . All those freezing days have been exported with the ice ..
  Meanwhile much of the rest of the Arctic has had a mild winter and this looks like really mattering this year .. b.c.
   
Title: Re: The 2019 melting season
Post by: Sterks on May 07, 2019, 02:18:38 PM
Back on topic;

JAXA extent continues to track with 2016 (a bad year indeed), yet the FDD implies the ice is actually in pretty good shape and is similar to 2013 (one of the best years of the decade)?
But 2013 was a rebound year not because of the state of the ice out of winter, but despite its bad state. One of the coolest June-July with that persistent cyclone.
The ice was so thin that even not so strong cyclone would make a hole. And the whole Pacific half was 1 year ice.
But there was no much heat in Summer.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 07, 2019, 03:13:55 PM
Looking at DMI 80N  (http://ocean.dmi.dk/arctic/meant80n.uk.php)(North Pole centric) temperature chart, the current (+/- a few days) 2019 temperature is above all other years except 2009, 10 and 18 (since 1999 at least).  Those 3 years all reverted back to the average this week.  Gerontocrat's 2019 sea ice area and extent data thread posts (https://forum.arctic-sea-ice.net/index.php/topic,2533.msg198186.html#msg198186) suggest continued warm:
Quote
GFS shows temperature anomalies varying from +2.5 to +3.5 celsius over the forecast period, with warmth over most of the Central Arctic and the CAA as far as Svalbard.
I would guess Simon's FFD chart (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg198202.html#msg198202) will show 2019 [technically 2018-19] slowly diverge further below the 2010s average (and 2013-14) (but never catch up to 2016-2018 years). 
Title: Re: The 2019 melting season
Post by: SimonF92 on May 07, 2019, 03:36:01 PM
Thanks for the comments everyone, I took gerontocrats advice and plotted the regression (sept minima not year maxima). FDD as a whole seems to be a pretty poor predictor of the cycle end-point.

This is an imperfect way to plot this, but my university firewall prevents me from accessing ftp files meaning I need to do it all manually. Also the fact these FDD data points are Jan-Jan, but the Sept minimum occurs 3/5ths into the year makes it worse.

I suppose what im trying to show here is that I shouldnt really have taken any inference from the FDD data about what way the ice could go  :)!
Title: Re: The 2019 melting season
Post by: gerontocrat on May 07, 2019, 03:52:34 PM
Thanks for the comments everyone, I took gerontocrats advice and plotted the regression (sept minima not year maxima). FDD as a whole seems to be a pretty poor predictor of the cycle end-point.

This is an imperfect way to plot this, but my university firewall prevents me from accessing ftp files meaning I need to do it all manually. Also the fact these FDD data points are Jan-Jan, but the Sept minimum occurs 3/5ths into the year makes it worse.

I suppose what im trying to show here is that I shouldnt really have taken any inference from the FDD data about what way the ice could go  :)!
Tealight's AWP graphs and maps give the daily and accumulated potential energy over and in the Arctic. Goto https://cryospherecomputing.tk/NRTawp.html

I attach his "High Arctic" graphs that include only the following regions: Kara Sea, Laptev Sea, East Siberian Sea, Chukchi Sea, Beaufort Sea, Canadian Archipelago, Central Arctic[/quote] incidentally, the same seas I show as the Central Arctic Seas in the area tables I post in the extent data thread.

I am sure that they give a much better idea of the current and future state of Arctic Sea Ice (as Tealight has proved once already - Champion of Antarctic Sea Ice Predictors ("No time for losers!?)
(https://forum.arctic-sea-ice.net/index.php/topic,1749.msg197999.html#msg197999)

Title: Re: The 2019 melting season
Post by: SimonF92 on May 07, 2019, 04:15:31 PM
Thanks for the comments everyone, I took gerontocrats advice and plotted the regression (sept minima not year maxima). FDD as a whole seems to be a pretty poor predictor of the cycle end-point.

This is an imperfect way to plot this, but my university firewall prevents me from accessing ftp files meaning I need to do it all manually. Also the fact these FDD data points are Jan-Jan, but the Sept minimum occurs 3/5ths into the year makes it worse.

I suppose what im trying to show here is that I shouldnt really have taken any inference from the FDD data about what way the ice could go  :)!
Tealight's AWP graphs and maps give the daily and accumulated potential energy over and in the Arctic. Goto https://cryospherecomputing.tk/NRTawp.html

I attach his "High Arctic" graphs that include only the following regions: Kara Sea, Laptev Sea, East Siberian Sea, Chukchi Sea, Beaufort Sea, Canadian Archipelago, Central Arctic
incidentally, the same seas I show as the Central Arctic Seas in the area tables I post in the extent data thread.

I am sure that they give a much better idea of the current and future state of Arctic Sea Ice (as Tealight has proved once already - Champion of Antarctic Sea Ice Predictors ("No time for losers!?)
(https://forum.arctic-sea-ice.net/index.php/topic,1749.msg197999.html#msg197999)
[/quote]

great, many thanks for these resources gerontocrat
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 07, 2019, 04:22:18 PM
Thanks, Gerontocrat! (2nded!)

I wonder where 2007 would show up on the "Accumulated Albedo" graph?  Also, a graph of "Accumulated Albedo" and September minimum extent would be very interesting to see...
Title: Re: The 2019 melting season
Post by: gerontocrat on May 07, 2019, 05:38:35 PM
Thanks, Gerontocrat! (2nded!)

I wonder where 2007 would show up on the "Accumulated Albedo" graph?  Also, a graph of "Accumulated Albedo" and September minimum extent would be very interesting to see...
Tealight said he had processed the regional data for the last 40 years.
I think we need to grovel to him for the graphs and/or data to give it a go ourselves.
Title: Re: The 2019 melting season
Post by: Thomas Barlow on May 08, 2019, 01:58:57 AM
Arctic Ocean basin just hit what looks like the lowest sea-ice extent on record for this time of year according to JAXA.
Graphed by Wipneus.
https://tinyurl.com/yyrmdp7z
Title: Re: The 2019 melting season
Post by: Aluminium on May 08, 2019, 07:12:34 AM
May 2-7.
Title: Re: The 2019 melting season
Post by: Sterks on May 08, 2019, 08:11:50 AM
The Laptev gap is also widening pretty fast...
Title: Re: The 2019 melting season
Post by: binntho on May 08, 2019, 08:43:41 AM
There is a hell of a lot of first-year ice in the Barents. I'd expect a free-fall in extent from that region pretty soon.
Title: Re: The 2019 melting season
Post by: oren on May 08, 2019, 11:00:47 AM
Yeah. The Atlantic export machine continues humming.
Title: Re: The 2019 melting season
Post by: bbr2314 on May 08, 2019, 11:03:55 AM
Siberia is also now rapidly losing its snowcover in the highest latitudes. Scroll EOSDIS at link for the full picture. As these losses accelerate expect the Laptev gap and ESS / Chukchi to begin melting and retreating in earnest. These are the regions where ice formation was most below normal this winter (and most of the Kara).

https://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2019-05-08-T00%3A00%3A00Z&z=3&v=-3134673.7846731436,925263.8615537761,2108206.2153268564,3472975.861553776
Title: Re: The 2019 melting season
Post by: uniquorn on May 08, 2019, 11:41:05 AM
Not much warmth in the pacific inflow as yet, just salinity. Atlantic water more dominant in the Laptev than last year (according to the model)
Mercator salinity 0m, mar1-may7
Title: Re: The 2019 melting season
Post by: uniquorn on May 08, 2019, 02:32:45 PM
Light cloud over the 'top' of the ess arm today. Worldview terra modis, local contrast enhanced and default, ascat may7 inset.
Title: Re: The 2019 melting season
Post by: Ajpope85 on May 08, 2019, 03:22:23 PM
Not much warmth in the pacific inflow as yet, just salinity. Atlantic water more dominant in the Laptev than last year (according to the model)
Mercator salinity 0m, mar1-may7

Can increased salinity cause additional bottom melt due to suppressing the freezing point?
Title: Re: The 2019 melting season
Post by: magnamentis on May 08, 2019, 05:05:59 PM
Not much warmth in the pacific inflow as yet, just salinity. Atlantic water more dominant in the Laptev than last year (according to the model)
Mercator salinity 0m, mar1-may7

Can increased salinity cause additional bottom melt due to suppressing the freezing point?

it not only can but does.

temps on the bottom of the ice are much higher most of the time (except summer) than at the surface and ice at those temps will certainly be impacted by higher salinity, not to says kind of eaten away, given salinity is reaching a certain level which is more or less what happens on the pacific side at the moment.

if you look not only at air temp anomalies but also at absolute temps, you will see that ice is retreating even in places where air temps are way below freezing point, this happens when either warm waters or more saline water is attacking the ice from below (or both at the same time. )
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on May 08, 2019, 06:15:57 PM
Not much warmth in the pacific inflow as yet, just salinity. Atlantic water more dominant in the Laptev than last year (according to the model)
Mercator salinity 0m, mar1-may7

That's basically where the Atlantic waters turn the corner after flowing along the Eastern continental shelf of the Nansen basin, heading back north. I wonder if there is a) shoaling causing deeper waters to rise and b) if that water is warmer than usual.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 08, 2019, 07:42:00 PM
New huge mighty crack in Beaufort.

Shot from today, 14:41h UTC

(actually, Ellesmere Island is a little further up... m) )
Title: Re: The 2019 melting season
Post by: Shared Humanity on May 08, 2019, 09:45:19 PM
Light cloud over the 'top' of the ess arm today. Worldview terra modis, local contrast enhanced and default, ascat may7 inset.

The entire ESS looks pretty fragmented. Is this normal for early May?
Title: Re: The 2019 melting season
Post by: uniquorn on May 08, 2019, 10:19:20 PM
Quote
Is this normal for early May?
Best to look at the stats for that. Every year is different when looking at the ice.
Title: Re: The 2019 melting season
Post by: oren on May 09, 2019, 03:08:03 AM
Looking at Wipneus' chart of the ESS ice area since 2012, it seems cracking/fragmentation events with the resulting temporary loss of area are common, but that the first sustained area drop that did not refreeze happened in 2017, in mid-May.
Should the ESS continue losing area rather than refreeze, this year could be even earlier than 2017.
Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 02:05:29 PM
New huge mighty crack in Beaufort.
Not a bad idea for the thickest ice to head north before the CAA opens up.
Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 02:38:30 PM
Not much warmth in the pacific inflow as yet, just salinity. Atlantic water more dominant in the Laptev than last year (according to the model) Mercator salinity 0m, mar1-may7
That's basically where the Atlantic waters turn the corner after flowing along the Eastern continental shelf of the Nansen basin, heading back north. I wonder if there is a) shoaling causing deeper waters to rise and b) if that water is warmer than usual.
I don't think they rise to the surface. That area was the last to melt last year. The ess arm has been stretched and refractured all last freezing season. It's probably just thin ice.
salinity/ascat here: https://forum.arctic-sea-ice.net/index.php/topic,2417.msg193927.html#msg193927
bathymetry/ascat: https://forum.arctic-sea-ice.net/index.php/topic,2417.msg193927.html#msg193927
Perhaps it hasn't really been that cold on the pacific side last freezing season.
polarportal ice surface temperature, sep24-may8
edit - forgot scale
Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 05:21:49 PM
Checking out the odd warm patch north of CAA towards the end of the ist animation above led me back to this fracture quite far east, north of Ellef Ringnes Island. Further east than the same dates in 2016. See here: https://forum.arctic-sea-ice.net/index.php/topic,2417.msg197767.html#msg197767

Worldview terra modis, beaufort/cab apr23-may8. Fracture shown larger on the right.
edit:Coincidentally, a cyclone will be dragging warm air over this fracture for the next couple of days. Opposite direction to the gyre so it either puts on the brakes or just adds turbulence.
Title: Re: The 2019 melting season
Post by: magnamentis on May 09, 2019, 05:30:04 PM
I don't think they rise to the surface. That area was the last to melt last year. The ess arm has been

if not rise to the surface, what about reach the surface by displacement, is that a term that would suit your opinion or do you assume that things stay the way they are now?
Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 05:36:30 PM
I don't think they rise to the surface. That area was the last to melt last year. The ess arm has been
if not rise to the surface, what about reach the surface by displacement, is that a term that would suit your opinion or do you assume that things stay the way they are now?
You would have to describe in more detail what would be displacing what. It's possible there is some mixing, but looking at the bouy data it takes a big event to disturb the halocline layers.
Title: Re: The 2019 melting season
Post by: magnamentis on May 09, 2019, 05:55:02 PM
I don't think they rise to the surface. That area was the last to melt last year. The ess arm has been
if not rise to the surface, what about reach the surface by displacement, is that a term that would suit your opinion or do you assume that things stay the way they are now?
You would have to describe in more detail what would be displacing what. It's possible there is some mixing, but looking at the bouy data it takes a big event to disturb the halocline layers.

ok, what i meant to ask is whether if year after year the atlantic currents would pump  more saline , hence heavier water into the arctic so that the layer with higher salinity would slowly grow from the seabed up-water-column till reaching sooner or later a depth that would allow for the remaing few meters to mix under open water conditions. i'm aware that there is more expert language to describe the theory but hope i was able to convey the essence of the idea ;) thanks.
Title: Re: The 2019 melting season
Post by: Alphabet Hotel on May 09, 2019, 05:56:32 PM
New huge mighty crack in Beaufort.

Shot from today, 14:41h UTC

(actually, Ellesmere Island is a little further up... m) )

I noticed that last night. It really stands out on the false color AMSR2 image.

Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 06:29:11 PM
ok, what i meant to ask is whether if year after year the atlantic currents would pump  more saline , hence heavier water into the arctic so that the layer with higher salinity would slowly grow from the seabed up-water-column till reaching sooner or later a depth that would allow for the remaing few meters to mix under open water conditions. i'm aware that there is more expert language to describe the theory but hope i was able to convey the essence of the idea ;) thanks.
No bouys in that location but whoi itp110 in the Beaufort shows what you describe, though it's unclear (to me) if it is pac or atl water. The image only shows data to 200m depth. Comparison with previous years shows the warm layer is thicker this year but there is very little evidence so far of mixing or 'displacement'.
My background knowledge of temperature/salinity is limited so I refer you to this post from AbruptSLR https://forum.arctic-sea-ice.net/index.php/topic,2391.msg170451.html#msg170451

with this quote about the Beaufort:
The one consideration that you are ignoring is that per the research that I reference in Reply #5, the relatively freshwater layer immediately above the deeper warm layer of water, is unstable.  So it is not that the deeper and denser warm water will magically float up through less dense cooler water, but rather that the upper cooler/fresher lay may well some day flow laterally away (into the North Atlantic) which would then leave the warm water closer to the surface.

whoi itp110 location and temperature/salinity 0-200m, may9
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on May 09, 2019, 06:48:57 PM

The freshwater layer of the Siberian seas is replenished by river water. I think Abrupt SLRs reference is to the the Beaufort Gyre, who's rotation appears to prevent the freshwater from flowing out.

The less dense freshwater on the ocean is always intrinsically unstable, rather like pouring less dense oil on water. It will flow away from its source across the denser water beneath unless there is some force keeping it in place.
Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 06:56:31 PM
Yes it is Rox. Thanks. I've edited the post to make that clear.
We really need a couple of bouys in the ess then. 
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 09, 2019, 07:42:53 PM
The Huge Mighty Crack has developed a parallel (southern) crack.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 09, 2019, 08:09:19 PM
Actually, just saw on Aqua / MODIS, there even is a third crack directly alongside the Canadian coastline.
Title: Re: The 2019 melting season
Post by: magnamentis on May 09, 2019, 08:17:25 PM
No bouys in that location but whoi itp110 in the Beaufort shows what you describe, though it's unclear (to me) if it is pac or atl water. The image only shows data to 200m depth. Comparison with previous years shows the warm layer is thicker this year but there is very little evidence so far of mixing or 'displacement'.
My background knowledge of temperature/salinity is limited so I refer you to this post from AbruptSLR https://forum.arctic-sea-ice.net/index.php/topic,2391.msg170451.html#msg170451

with this quote about the Beaufort:
The one consideration that you are ignoring is that per the research that I reference in Reply #5, the relatively freshwater layer immediately above the deeper warm layer of water, is unstable.  So it is not that the deeper and denser warm water will magically float up through less dense cooler water, but rather that the upper cooler/fresher lay may well some day flow laterally away (into the North Atlantic) which would then leave the warm water closer to the surface.

whoi itp110 location and temperature/salinity 0-200m, may9

thanks a lot, that's more than good enough.

again the question whether it is atlantic or pacific wouldn't matter as far as the principle is concerned, i should have labeled the atlantic part in my question as "an example". of course if it applies to the atlantic, it can happen in from each side, only that the atlantic is renown to provide a huge amount of water pumped into the arctic.

as to the other point of surface layers flowing away, that makes totally sense as a possibility and i never thought about that before and i love to learn about entirely new possibilities, ideas and/or facts, special thanks for you valued feedback.
Title: Re: The 2019 melting season
Post by: uniquorn on May 09, 2019, 09:31:01 PM
Actually, just saw on Aqua / MODIS, there even is a third crack directly alongside the Canadian coastline.
Yesterday's worldview aqua modis of the same area, close to prince patrick. A small cyclone moving eastwards from amundsen gulf has lifted what should be some of our thickest ice from the CAA coastline. More disturbing (to me) are the fine lateral fractures which have little chance of refreeze.
3 more days of southerlies are forecast. Default and enhanced contrast.
Title: Re: The 2019 melting season
Post by: Sterks on May 10, 2019, 12:58:07 AM
A wave of continental warm air is starting to loom in the short range EC model. The beginning is still far in the horizon, 6-7 days but pretty much agrees with that 15 day or so prediction by sark like a week ago. Powerful HP dominating the Arctic and potentially pulling really warm air from the continent over CAA and Beaufort in 10 days. We’ll see...
Title: Re: The 2019 melting season
Post by: sark on May 10, 2019, 01:11:31 AM
I wish I hadn't said that, but it is obvious.  Something broke.
Title: Re: The 2019 melting season
Post by: uniquorn on May 10, 2019, 01:37:18 AM
As a complete novice at 500mB, how did you do it?
Title: Re: The 2019 melting season
Post by: Thomas Barlow on May 10, 2019, 05:04:52 AM
All 3 - NASA, JAXA, & Uni Mamburg - now showing the Arctic Ocean basin lowest for this time of year.

Graph by Wipneus.
https://tinyurl.com/yyll29rx
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 10, 2019, 05:57:02 AM
The Huge Mighty Crack made it's way to the Nares arch.  :-[
Title: Re: The 2019 melting season
Post by: Aluminium on May 10, 2019, 06:54:24 AM
May 5-9.
Title: Re: The 2019 melting season
Post by: bbr2314 on May 10, 2019, 07:30:28 AM
Siberia's snow melt has accelerated rapidly. Seven days ago there were only smidges of cover lacking. Now there are only mountainous smudges remaining.

Title: Re: The 2019 melting season
Post by: Alphabet Hotel on May 10, 2019, 08:15:22 AM
Why do I keep getting the impression that the entire basin of ice is rotating clockwise?
Title: Re: The 2019 melting season
Post by: sark on May 10, 2019, 08:43:09 AM
Why do I keep getting the impression that the entire basin of ice is rotating clockwise?

High pressure.  it's all anticyclonic from space to surface.

https://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-84.79,85.32,419
Title: Re: The 2019 melting season
Post by: sark on May 10, 2019, 08:51:09 AM
As a complete novice at 500mB, how did you do it?

Autosquint https://imgur.com/a/E2cNoiv
Title: Re: The 2019 melting season
Post by: Often Distant on May 10, 2019, 11:54:27 AM
Quote from: bbr2314

Siberia's snow melt has accelerated rapidly.

Interesting, worldview is displaying fires/thermal anomalies causing or resulting from recent rapid snow melt patches opening up through Siberia near 70°N. The speed between ice cover and fire is rather worrisome with summer yet weeks away.


A thermal anomaly causing rapid snow melt through the Kamchatka Peninsula weeks back was due to volcanic activity.
Title: Re: The 2019 melting season
Post by: gerontocrat on May 10, 2019, 12:34:57 PM
Quote from: bbr2314

Siberia's snow melt has accelerated rapidly.
Interesting, worldview is displaying fires/thermal anomalies causing or resulting from recent rapid snow melt patches opening up through Siberia near 70°N. The speed between ice cover and fire is rather worrisome with summer yet weeks away.

The attached map from Environment Canada shows variation in snow depth from average. The red line shows average extent.

Snow cover extent in Siberia is average, as is North America extent apart from NE Canada. i.e. no big deal.
Title: Re: The 2019 melting season
Post by: Klondike Kat on May 10, 2019, 01:24:03 PM
Thank you gerontocrat for that nice map.
Title: Re: The 2019 melting season
Post by: dosibl on May 10, 2019, 02:49:22 PM
Snow cover graphs/maps have also been added at cryospherecomputing.tk, I've really been digging the new site.
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 10, 2019, 03:45:50 PM
Why do I keep getting the impression that the entire basin of ice is rotating clockwise?

High pressure.  it's all anticyclonic from space to surface.

https://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-84.79,85.32,419
Add that North Atlantic Drift isn't what it used to be so little to no opposite forces.
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 11, 2019, 06:41:44 AM
Glacier that moved 60 feet a year, now moves 60ft a day; (Vavilov Ice Cap in Laptev)

https://earthobservatory.nasa.gov/images/144790/a-surprising-surge-at-vavilov-ice-cap

Another link with a good video;

https://earther.gizmodo.com/watch-a-russian-glacier-experience-sudden-unprecedente-1829194880

Satellite time lapse;

https://earthengine.google.com/timelapse#v=79.29346,94.90916,7.13,latLng&t=0.8&ps=100&bt=
19840101&et=20181231&startDwell=0&endDwell=0
Title: Re: The 2019 melting season
Post by: Shared Humanity on May 11, 2019, 02:37:08 PM
nice video
Title: Re: The 2019 melting season
Post by: magnamentis on May 11, 2019, 06:00:23 PM
Glacier that moved 60 feet a year, now moves 60ft a day; (Vavilov Ice Cap in Laptev)

https://earthobservatory.nasa.gov/images/144790/a-surprising-surge-at-vavilov-ice-cap

Another link with a good video;

https://earther.gizmodo.com/watch-a-russian-glacier-experience-sudden-unprecedente-1829194880

Satellite time lapse;

https://earthengine.google.com/timelapse#v=79.29346,94.90916,7.13,latLng&t=0.8&ps=100&bt=
19840101&et=20181231&startDwell=0&endDwell=0

THX
Title: Re: The 2019 melting season
Post by: pleun on May 11, 2019, 06:44:17 PM
maybe it's just me, but with all the negative forecasts, I would have expected extent to go down much faster than it actually does. any thoughts ?
Title: Re: The 2019 melting season
Post by: bluice on May 11, 2019, 07:08:10 PM
https://cires.colorado.edu/news/unprecedented-ice-loss-russian-ice-cap

Vavilov ice cap lost 4,5 km3 of volume in one year during it’s collapse. There’s a lot of talk about MISI and MICI and whatnot, but if one wonders how an unstable abruptly collapsing ice sheet looks like, this is a pretty good candidate. It seems ice sheets are a lot less stable than what was thought before.
Title: Re: The 2019 melting season
Post by: uniquorn on May 11, 2019, 07:11:22 PM
Lincoln Sea ice not looking good today.
Worldview aqua modis, may10-11 https://go.nasa.gov/2E47pcm
Title: Re: The 2019 melting season
Post by: meddoc on May 11, 2019, 07:21:44 PM
Lincoln Sea ice not looking good today.


YIKES!
Nothing like that in recent History this early.
Title: Re: The 2019 melting season
Post by: Stephan on May 11, 2019, 08:11:58 PM
...and you can see one of the "amoeba ice remains" of VBC (forgot the number - for details see "VBC poll thread" in the Greenland folder) breaking up.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 11, 2019, 08:17:16 PM
maybe rotate 90deg and post on melting thread?

Here we go!

Animation of the extreme crackification alongside Greenlands most northern coastline.

(Click GIF to animate)
Title: Re: The 2019 melting season
Post by: oren on May 11, 2019, 08:47:22 PM
At least it means a temporary reversal of Fram export. The worst movements are continuos ones.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 11, 2019, 08:54:39 PM
That NNW Greenland coastal crack is quite something!  If movement of the 'triangle' is more than a temporary or intermittent thing, this year will be different from at least most years (all? - would have to do research, and not just remember), and yes, 'worst' possibility.  The ice there certainly hasn't aged long, compared with most previous years. 

There has been many a discussion on the effect a frequently cracking ice pack will have:  things like more young ice and more heat loss from the Arctic Ocean, more mobility, higher dispersion (area/extent).
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 11, 2019, 09:23:18 PM
At least it means a temporary reversal of Fram export.

Sorry Oren, but i have my doubts about this. For how i see it Fram export has rather increased recently. I will keep this in sight and will report.

Edit: add GIF 07.04 to 11.05 for reference.
Title: Re: The 2019 melting season
Post by: uniquorn on May 11, 2019, 10:07:09 PM
Mercator (model) salinity 0m and 34m indicating a surge of atlantic water around north greenland combined with returning atlantic water from the north. The surge may be temporary, the other isn't.

The CAA coast isn't looking too good either. https://go.nasa.gov/2DYOu2z
@b_l nice, but there are many repeat frames in that ani
Title: Re: The 2019 melting season
Post by: oren on May 11, 2019, 11:02:33 PM
Thanks for the gif b_l. It does seem not to be slowing at all.
Title: Re: The 2019 melting season
Post by: uniquorn on May 11, 2019, 11:27:55 PM
Worldview aqua modis caa and nth greenland today.
Title: Re: The 2019 melting season
Post by: be cause on May 12, 2019, 02:09:02 AM
Worldview aqua modis caa and nth greenland today.

 cheers Uniquorn .. I looked back to 11.05.2007 on Worldview and saw almost the same pattern of cracks . I was wondering if an active Nares could be more important than anyone has imagined ? It is as if the Arctic's strength .. the Canadian - Greenland - Pole triangle is compromised .. b.c.
Title: Re: The 2019 melting season
Post by: Aluminium on May 12, 2019, 08:16:07 AM
May 7-11.
Title: Re: The 2019 melting season
Post by: oren on May 12, 2019, 08:51:27 AM
May 7-11.
I note what looks like an open water refreeze in the Laptev.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 12, 2019, 09:26:53 AM
The Laptev Sea via Nasa Worldview, 01.05. to 12.05.

Looks like ice drift, no?
Title: Re: The 2019 melting season
Post by: Neven on May 12, 2019, 10:24:08 AM
Probably a combination of re-freezing and fragmented ice moving back in, though the latter is now becoming more dominant. The animation below (Laptev April 24-May 12) shows there was more re-freezing up to a few days ago. Also keep in mind that there's some flashing/unflashing going on in the Uni Bremen SIC animation Aluminium posted.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 12, 2019, 11:28:50 AM
What's flashing/unflashing Neven?
Title: Re: The 2019 melting season
Post by: uniquorn on May 12, 2019, 11:32:16 AM
ecmwf and gfs indicating temperature around -4C in that area of Laptev. Refreeze? A bit too cloudy to tell. edit: correction, there is refreeze https://go.nasa.gov/2JBxqDp

uni-hamburg amsr2-uhh, may4-11 showing the fracture spreading west to east along the CAA coast.
Worldview viirs brightness temperature (band15) night appears to show a surge continuing eastward around the north of greenland.
Something else happening as well as the possible currents indicated upthread.
edit: Southerlies on the 7th, cyclone on the 8th dragging more southerlies along the coast maybe? Small cyclone in Lincoln today.
Title: Re: The 2019 melting season
Post by: Neven on May 12, 2019, 12:17:49 PM
What's flashing/unflashing Neven?

Sometimes large swathes of ice can disappear from one day to the next on the Uni Bremen sea ice concentration maps. This is now colloquially known as 'flash melting', or 'flashing', as in 'flash, it's gone'. But some of this ice then re-appears again in subsequent days, it 'unflashes'.

I introduced the term 'flash melting' back in 2011 (https://neven1.typepad.com/blog/2011/08/flash-melting.html), as a pun on 'flash flooding'. I used the term 'unflashing' in this 2012 post (https://neven1.typepad.com/blog/2012/08/arctic-storm-part-2-the-color-purple.html), for instance, during the GAC-2012.
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 12, 2019, 12:23:35 PM
What's flashing/unflashing Neven?

Sometimes large swathes of ice can disappear from one day to the next on the Uni Bremen sea ice concentration maps. This is now colloquially known as 'flash melting', or 'flashing', as in 'flash, it's gone'. But some of this ice then re-appears again in subsequent days, it 'unflashes'.

I introduced the term 'flash melting' back in 2011 (https://neven1.typepad.com/blog/2011/08/flash-melting.html), as a pun on 'flash flooding'. I used the term 'unflashing' in this 2012 post (https://neven1.typepad.com/blog/2012/08/arctic-storm-part-2-the-color-purple.html), for instance, during the GAC-2012.
This may even have a physical explantion, as some satellite sensors may get cofused  with low altitude fog or surface melt, the initiation of meltpooling.
Title: Re: The 2019 melting season
Post by: Klondike Kat on May 12, 2019, 03:40:59 PM
What's flashing/unflashing Neven?

Sometimes large swathes of ice can disappear from one day to the next on the Uni Bremen sea ice concentration maps. This is now colloquially known as 'flash melting', or 'flashing', as in 'flash, it's gone'. But some of this ice then re-appears again in subsequent days, it 'unflashes'.

I introduced the term 'flash melting' back in 2011 (https://neven1.typepad.com/blog/2011/08/flash-melting.html), as a pun on 'flash flooding'. I used the term 'unflashing' in this 2012 post (https://neven1.typepad.com/blog/2012/08/arctic-storm-part-2-the-color-purple.html), for instance, during the GAC-2012.
This may even have a physical explantion, as some satellite sensors may get cofused  with low altitude fog or surface melt, the initiation of meltpooling.

It may just be that currents move the ice/slush into compacted regions such that the 15% threshold is breached, and are registered as such in the satellite sensors - as Neven mentioned in his original definition.  Just noise in the system.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 12, 2019, 03:43:54 PM
What's flashing/unflashing Neven?

Sometimes large swathes of ice can disappear from one day to the next on the Uni Bremen sea ice concentration maps. This is now colloquially known as 'flash melting', or 'flashing', as in 'flash, it's gone'. But some of this ice then re-appears again in subsequent days, it 'unflashes'.

I introduced the term 'flash melting' back in 2011 (https://neven1.typepad.com/blog/2011/08/flash-melting.html), as a pun on 'flash flooding'. I used the term 'unflashing' in this 2012 post (https://neven1.typepad.com/blog/2012/08/arctic-storm-part-2-the-color-purple.html), for instance, during the GAC-2012.

Thanks, Neven, Kat and Pmt. :)
Title: Re: The 2019 melting season
Post by: Stephan on May 12, 2019, 04:23:35 PM
What's flashing/unflashing Neven?

Sometimes large swathes of ice can disappear from one day to the next on the Uni Bremen sea ice concentration maps. This is now colloquially known as 'flash melting', or 'flashing', as in 'flash, it's gone'. But some of this ice then re-appears again in subsequent days, it 'unflashes'.

I introduced the term 'flash melting' back in 2011 (https://neven1.typepad.com/blog/2011/08/flash-melting.html), as a pun on 'flash flooding'. I used the term 'unflashing' in this 2012 post (https://neven1.typepad.com/blog/2012/08/arctic-storm-part-2-the-color-purple.html), for instance, during the GAC-2012.
I remember last July when almost all of the Hudson Bay Sea Ice "disappeared" over night which obviously was not true. Some days later the sea ice "reappeared" in the graphs and tables...
Title: Re: The 2019 melting season
Post by: HapHazard on May 12, 2019, 08:56:45 PM
So, will the ice entirely lift off from the CAA/Greenland coast?

(I had long thought that would be the death knell if it happened in, say, August - but this is different.)
Title: Re: The 2019 melting season
Post by: JayW on May 12, 2019, 09:15:29 PM
ECMWF suggests some southerly winds over the Kara Sea over the next couple days, might see meaningful losses three over the next couple days.  At day three, a period of strong easterly winds should begin north of Alaska, this'll could really open up the Beaufort (beginning in 3 days) I'm well aware of the pitfalls of trusting the models, but this has been consistent in several models.

Title: Re: The 2019 melting season
Post by: gerontocrat on May 12, 2019, 10:39:06 PM
So, will the ice entirely lift off from the CAA/Greenland coast?

Images from Greenland's Martin Jessup and Nord areas, East from Lincoln Sea.
Big open cracks?
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 12, 2019, 10:54:25 PM
Big open cracks?

Yes. All the way down to the Beaufort Sea. One giant crack and there is no connecting to any CAA coastline anywhere anymore at the moment.
Title: Re: The 2019 melting season
Post by: uniquorn on May 12, 2019, 11:25:44 PM
Worldview aqua modis, lincoln and wendel seas, may12 or nearest clearest day, 2010-2019
Maybe it's not so bad.
Title: Re: The 2019 melting season
Post by: Rich on May 13, 2019, 12:00:01 AM
So...new poster here trying to orient myself to what's going in the Arctic. So many variables its tough to get a feel.

Looking at uniquorns gif in post # 776, it appears the ice in the entire Arctic is moving as one. Lifting off the Greenland and Canadian coast and rotating in a clockwise direction.

What stops the whole thing from continuing to rotate around to Fram Strait and exiting?

Title: Re: The 2019 melting season
Post by: Niall Dollard on May 13, 2019, 01:27:08 AM
2016 has been mentioned quite a lot (as an analog to this year).

In early May 2016 the cracks were even bigger than this year. Only plus was at least the Nares was blocked then.

Click to animate
Title: Re: The 2019 melting season
Post by: Frivolousz21 on May 13, 2019, 03:16:26 AM
I haven't followed any of this so bear with me if this is a wrong conclusion.

But it looks like the Euro and the global forecasting system.  I'm using talk to text that's why I didn't just say GFS because sometimes it doesn't come out right.


Anyways both of them at least on their runs today in about 48 to 60 hours start essentially a hemispheric wide pattern change and the upper latitudes.

You can see not just high pressure blowing up in around the Beaufort sea.

But the huge banana high pressure structure becomes evident.  With the cut-off vortex just south of Greenland and over Eastern Canada.

The way the euro depicts this straight nasty.

But both models are now onto this.


Infact the GEM and UKMET is going down the same path.


For those who are not aware:


Meteorology speaking this setup is essentially the Holy Grail of having a record-setting Arctic sea ice loss during the summer.

Solar energy right now is booming over the arctic.  The best way to set up things for huge loses of sea ice is sprawling upper level atmospheric ridges of high pressure that exist from top down.

This is the path to dry sinking air and wall to wall sunny skies. 

We have never had a May 20-30th GARGANTUAN RIDGE that preconditioned the ice for huge June and July loses.


Stay tuned
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 13, 2019, 04:43:03 AM
The way the euro depicts this straight nasty.

For those who are not aware:

Meteorology speaking this setup is essentially the Holy Grail of having a record-setting Arctic sea of sea ice is sprawling upper level atmospheric ridges of high pressure that exist from top down.

This is the path to dry sinking air and wall to wall sunny skies. 

We have never had a May 20-30th GARGANTUAN RIDGE that preconditioned the ice for huge June and July loses.

Stay tuned

https://gfycat.com/wealthylonelyanophelesmosquito-great-outdoors-old-96er
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 13, 2019, 05:21:36 AM
So...new poster here trying to orient myself to what's going in the Arctic. So many variables its tough to get a feel.

Looking at uniquorns gif in post # 776, it appears the ice in the entire Arctic is moving as one. Lifting off the Greenland and Canadian coast and rotating in a clockwise direction.

What stops the whole thing from continuing to rotate around to Fram Strait and exiting?

The traditional answer has been 'the next winter'. Nowadys we often see ridges and throughs enter the Arctic on few locations and these would slow the regular anticyclonic pattern down, often a low pressure area enters Beaufort Sea, or an Atlantic one get stuck somewhere round Svalbard, instead of tracking the coastline like they used to. The next push of warmer air from south might well disrupt this pattern that indeed enhances the natural (due earths rotation) anticyclonic flow of Arctic waters.
Title: Re: The 2019 melting season
Post by: epiphyte on May 13, 2019, 07:45:59 AM

This is the path to dry sinking air and wall to wall sunny skies. 


I think you're likely not wrong Friv - it kind of looks that way.

The ironic part is that whilst all those southward-blowing winds will be pushing ice out into the death zone, carrying the fog and clouds that form over warming ice and open water out of the picture, and leaving the midnight sun to do it's thing, half the people on this forum will be watching the temporarily low extent loss (perhaps even increase) and declaring the whole season a nothingburger.

Title: Re: The 2019 melting season
Post by: meddoc on May 13, 2019, 08:10:48 AM
So...new poster here trying to orient myself to what's going in the Arctic. So many variables its tough to get a feel.

Looking at uniquorns gif in post # 776, it appears the ice in the entire Arctic is moving as one. Lifting off the Greenland and Canadian coast and rotating in a clockwise direction.

What stops the whole thing from continuing to rotate around to Fram Strait and exiting?

Well, that's gonna be the Big Question. As winds & storms getting ever stronger in lower latitudes, even- I guess at the Arctic it must be more pronounced.

That kind of a lift- off caught my Attention first in August 2015, when I first saw the Ice Cap detached from Greenland + CAA. It was a shocker even back then.
Let alone now, so early in May...
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 13, 2019, 09:26:09 AM
One month of Kara Sea. A tale of Atlantic waters?

13.04. to 13.05. via Nasa Worldview

(Click GIF to animate)
Title: Re: The 2019 melting season
Post by: gerontocrat on May 13, 2019, 09:55:59 AM
The ironic part is that whilst all those southward-blowing winds will be pushing ice out into the death zone, carrying the fog and clouds that form over warming ice and open water out of the picture, and leaving the midnight sun to do it's thing, half the people on this forum will be watching the temporarily low extent loss (perhaps even increase) and declaring the whole season a nothingburger.
Sea ice extent and area data is - what is. The midnight sun over the central arctic is - what might be, clouds and fog permitting. In 2017 and 2018 the melting season did become to some extent a nothingburger, despite many predictions of sea ice Armageddon. Instead, it was very slow start to the freeze season, in line with some models' predictions, that was more significant.

We will see if the early signs of a new weather pattern picked up by Frivousz21 happens, or does not. Meanwhile JAXA sea ice extent has gone from lowest to third lowest in short order.
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 13, 2019, 10:36:45 AM
One month of Kara Sea. A tale of Atlantic waters?

13.04. to 13.05. via Nasa Worldview

(Click GIF to animate)
Kara and Laptev are indeed interesting wrt to the origin of waters, Kara is usually Atlantic mixed with melt water from Ob and Yenisei but Laptev likely has a Pacific component to it (also Lena river). ESS is almost fully Pacific/Arctic (no huge rivers) , Chukchi less Arctic. Barents is  about fully Atlantic by now.
Title: Re: The 2019 melting season
Post by: johnm33 on May 13, 2019, 11:32:52 AM
"What stops the whole thing from continuing to rotate around to Fram Strait and exiting?"
The sheer mass of ice gathered around the pole used to be the answer. To move that south it has to be accelerated by about 22kph per deg. There's much less there and for the whole winter/freeze there's been a steady rotation pushing the densest ice across from the NSI towards anywhere between Fram and Axel Heiberg is., beneath it there's been a freshwater current which has sealed the cracks as it moved and reduced compaction,thus it hasn't had the integrity to close the Nares exit without which there can be no build up of mass around the pole. With enough integrity the 'polar mass' would rotate carrying the dense ice past the exits of Fram/Nares to either crush against the CAA or cruise around the arctic for another year or so, very little evidence of that this year.
New answer, not much. Welcome, did you bring your own popcorn?
Title: Re: The 2019 melting season
Post by: BenB on May 13, 2019, 11:47:24 AM
Although we've had mainly huge positive temperature anomalies over the Arctic for some time now, temperatures have generally remained below zero in the central basin. That looks like it will change over the coming week, with sustained temperatures above freezing in the Beaufort and Chukchi, spreading to the ESS and Laptev. Hudson will also be above freezing, so melting should start to pick up there. This is for Wednesday, so it should be fairly reliable:

(https://keytwist.net/floe/external/t2/16.png/)
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 13, 2019, 12:00:11 PM
Nice of them to put a darker blue stripe at -4°C or thereabouts to signal the freezing temperature of very salty water. And how much will the waves effect and disturb the formation of ice? => https://forum.arctic-sea-ice.net/index.php/topic,2417.0.html
Title: Re: The 2019 melting season
Post by: Carex on May 13, 2019, 01:24:55 PM
Will those six or seven lows, forecast for Wednesday, surrounding a polar high be enough to rotate the entire cap now that it seems unattached to shore?  They look like little sprockets surrounding a large central gear.
Title: Re: The 2019 melting season
Post by: Pmt111500 on May 13, 2019, 03:05:11 PM
Will those six or seven lows, forecast for Wednesday, surrounding a polar high be enough to rotate the entire cap now that it seems unattached to shore?  They look like little sprockets surrounding a large central gear.
Likely not, the islands north of Siberia (Severnaja Zemlja and others too) are a permanent stick in that wheel. Maybe later in summer.
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 13, 2019, 06:23:03 PM
So...new poster here trying to orient myself to what's going in the Arctic. So many variables its tough to get a feel.

Looking at uniquorns gif in post # 776, it appears the ice in the entire Arctic is moving as one. Lifting off the Greenland and Canadian coast and rotating in a clockwise direction.

What stops the whole thing from continuing to rotate around to Fram Strait and exiting?

Check out this timelapse; https://www.youtube.com/watch?v=Vj1G9gqhkYA

Good commentary that explains things.
Title: Re: The 2019 melting season
Post by: Rich on May 13, 2019, 07:49:26 PM
So...new poster here trying to orient myself to what's going in the Arctic. So many variables its tough to get a feel.

Looking at uniquorns gif in post # 776, it appears the ice in the entire Arctic is moving as one. Lifting off the Greenland and Canadian coast and rotating in a clockwise direction.

What stops the whole thing from continuing to rotate around to Fram Strait and exiting?

Check out this timelapse; https://www.youtube.com/watch?v=Vj1G9gqhkYA

Good commentary that explains things.


Thanks for the video clip. A picture paints a thousand words.
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 13, 2019, 11:15:13 PM
The whole icepack is starting to rotate and it will get going when the forecast high pressure intensifies. However, it never moves that fast and the Siberian islands do cause ice to pile up and distort the pattern of rotation. The recent pull offs of the pack from both the CAA and Greenland are the first steps in the process. Next comes the powerful high pressure and we'll watch it slowly spin clockwise.
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 14, 2019, 12:15:11 AM
Yes, Frivolous, this is what I was concerned about 2 weeks ago when the end stratospheric warming went crazy. It set up a pattern of spin down from the stratosphere intensifying blocking patterns in the high north. The strong Scandinavian blocking led to very intense upward wave energy transfer that caused the powerful end warming in the stratosphere. Over the next several months the stratospheric spin down will repeatedly couple with blocks in the troposphere which also rotate clockwise. Upward energy transfer into the stratosphere is over for the summer but downward effects are possible when there's high pressure over the Arctic because the clockwise spins may align. You wrote:

For those who are not aware:


Meteorology speaking this setup is essentially the Holy Grail of having a record-setting Arctic sea ice loss during the summer.

Solar energy right now is booming over the arctic.  The best way to set up things for huge loses of sea ice is sprawling upper level atmospheric ridges of high pressure that exist from top down.

This is the path to dry sinking air and wall to wall sunny skies.

We have never had a May 20-30th GARGANTUAN RIDGE that preconditioned the ice for huge June and July loses.


Stay tuned

Over the weekend I reviewed the stratospheric patterns for summers for the past 20 years and found that the stratospheric end warming conditions increase the odds of the Arctic oscillation being positive or negative - in this case high pressure means negative - but there are many other things going on.

What's starting to happen in May looks like the worst case set up for Arctic ice melt. The figures I looked at showed variability that give me very low confidence in a July forecast based on the end warming patterns by themselves. However, we can use the end stratospheric warming information to evaluate the likelihood that a global model such as the CFS model is making a decent forecast. The CFS model struggles with ocean upwelling, melting snow and ice, and the evolution over time of SSTs, but, based on my experience it may have a good handle on large scale stratospheric tropospheric coupling in the summer.

If it does, were going to witness a new record low in sea ice extent, area and volume this year. The latest CFS runs predict the high pressure and subsidence over the pole and Greenland will persist into July. This CFS model forecast makes sense because of the intense late end season stratospheric warming at the end of April.
Title: Re: The 2019 melting season
Post by: Trebuchet on May 14, 2019, 01:40:51 AM
 Surface melt in the north of fox basin today. Crazy weather. Last year melt started on June 11th...

Title: Re: The 2019 melting season
Post by: epiphyte on May 14, 2019, 03:23:55 AM
The ironic part is that whilst all those southward-blowing winds will be pushing ice out into the death zone, carrying the fog and clouds that form over warming ice and open water out of the picture, and leaving the midnight sun to do it's thing, half the people on this forum will be watching the temporarily low extent loss (perhaps even increase) and declaring the whole season a nothingburger.
Sea ice extent and area data is - what is. The midnight sun over the central arctic is - what might be, clouds and fog permitting. In 2017 and 2018 the melting season did become to some extent a nothingburger, despite many predictions of sea ice Armageddon. Instead, it was very slow start to the freeze season, in line with some models' predictions, that was more significant.

We will see if the early signs of a new weather pattern picked up by Frivousz21 happens, or does not. Meanwhile JAXA sea ice extent has gone from lowest to third lowest in short order.

@gerontocrat - don't get me wrong - it wasn't my intent to suggest that changes in extent are uninformative (and BTW your sterling work in tracking them is much appreciated, by me as much as everyone else).  Rather I was opining that depending on the circumstances and the time of year, they might indicate something other than what many might think.

Should Friv's prediction come to pass, I'd hazard that it will likely lead to relatively clear skies, increased ice dispersal/more open water/reduced albedo in the CAB, right at the one time of year when the arctic gets more solar energy every day than anywhere else on the planet. That can't be good. Should this happen, however,  it will likely be concomitant with either a slowing of the decrease, or an actual increase, in extent.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 14, 2019, 04:04:23 AM
Everything in the barents south of the invisible line between the norther tip of severny island and southern tip of svalbard is going POOF.
Title: Re: The 2019 melting season
Post by: Rich on May 14, 2019, 05:18:40 AM
As someone who has been lurking here for a few months, I just want to offer a general thanks to the people who populate this community and give it life.

My interest as a climate activist is trying to understand the potential inflection points in earth's climate system and distributing an understanding to others to help tip people into action. Sea ice seems like an extremely important variable to follow because of it's impact on weather and the feedback effects associated with lost albedo and the coming phase change when  the energy currently associated with melting ice is more fully allocated to warming the water.

From the perspective of longer term trends, things obviously don't look good for the Arctic sea ice. The curve of 1980's average ice to 90's to 00's to the current decade is obviously steady decline and our understanding of increasing GHG levels leads us to the almost inescapable conclusion that we're heading in the direction of a BOE in coming decades.

From a standpoint of risk management, it's interesting to hear about the potential short-term weather phenomena that could impact the ice. It conveys to a meteorological layperson like myself the vulnerability of the situation.

As a proxy for the layperson struggling to synthesize meaning from what's going on here, I can tell you that it isn't easy to get a feel for the overall health of the ice. I see the objective 2D measures of extent and area which seem redundant and think the 3D measure is probably at least as valuable but more arduous to measure. I see pictures of the quality of the ice and the comments of those of you who have been following this for years which lead me to an impression (admittedly biased) that things are generally degrading even if the generally accepted 2D measure isn't setting a record low.

This is largely a weather thread. I find the predictions and the conversation interesting. there's a lot to learn here.





Title: Re: The 2019 melting season
Post by: Pmt111500 on May 14, 2019, 05:55:15 AM
@Rich yep, the Arctic weather thread, with occasional visits to temperate weather. Interesting developments occasionally create interesting discussion.

Generally, weather on lower latitudes is discussed within threads in the 'consequences'-section, by the headlines, for example:
Weird and not weird weather (weird preferred) : https://forum.arctic-sea-ice.net/index.php/topic,323.0.html
Droughts 2019: https://forum.arctic-sea-ice.net/index.php/topic,2579.0.html
,Heatwaves: https://forum.arctic-sea-ice.net/index.php/topic,2352.0.html

Antarctica has little weather variability so weather of southernmost Oceans and Antarctica itself doesn't have a dedicated thread, and may pop up in 'Antarctica', here, or elsewhere if there's some curious things going on. Some antarctic heatwave (weather over melting point) was discussed at least some years back somewhere.
Title: Re: The 2019 melting season
Post by: Aluminium on May 14, 2019, 07:23:14 AM
May 9-13.
Title: Re: The 2019 melting season
Post by: Sterks on May 14, 2019, 08:49:25 AM
Watching tropicaltidbits.com
The worse forecast are going to come to fruition, what can I add. Beaufort and CAA especially are going to suffer big for the time of the year.
Coincidentally or not, snow melt has accelerated all around high latitudes of the NH according to Rutgers, not as warm as 2016 but definitely warming up again.
The perfect storm toward June (that could be quenched by the perfectly normal storm in June,...)
Title: Re: The 2019 melting season
Post by: Eco-Author on May 14, 2019, 11:54:57 AM
Try to keep up daily... What's happening in Nares is shocking...  I know people keep export of frame, do we have a measure of how much goes through Nares?  I'd love to see the frame numbers again.  Cracking speaks to the health of the ice.  If the ice was solid and thick, you'd likely not see so many smaller parallel cracks-Maybe a few big ones.  Seems as soon as the ice cracks smaller chuncks fill in which isn't a good sign of health.  The more cracks--I think--the more the wind has surface to push on, not to mention being thinner, so perhaps the whole spinning movement is all that extra surface area to push against? 
Title: Re: The 2019 melting season
Post by: El Cid on May 14, 2019, 12:12:47 PM
I am no expert, but the last years have taught me that for every individual season weather is the allimportant thing despite the long term warming trend of the globe. What is the worst possibble combination for ice (the way I understand it)? Persistent low pressure and cloudy skies during winter to keep the Arctic warm; then high pressure/sunny skies during peak insolation (May,June,July), then big storms (low pressure systems) in August/September.

So far, we have had plenty of sunshine (see chart for past 30 days of sea level pressure), and this , coupled with the fairly new trend (past 2 years) of Pacification leading to the early opening of the Bering is probably weakening the ice very much. We probably won't see it in the extent numners tomorrow, or next week, but given the forecast for the rest of the month (described above by others), we could see serious damage, come June.
Title: Re: The 2019 melting season
Post by: iceman on May 14, 2019, 01:57:05 PM

.... The latest CFS runs predict the high pressure and subsidence over the pole and Greenland will persist ....


That does look serious. Especially if the highs appear where forecast for June, with the Beaufort and Chukchi already in bad shape and absorbing lots of insolation.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 14, 2019, 04:40:14 PM
The Pechora Sea just had a ROUGH couple days.
Title: Re: The 2019 melting season
Post by: jdallen on May 15, 2019, 04:49:07 AM

.... The latest CFS runs predict the high pressure and subsidence over the pole and Greenland will persist ....


That does look serious. Especially if the highs appear where forecast for June, with the Beaufort and Chukchi already in bad shape and absorbing lots of insolation.
The "Lift off" in the Chukchi is very concerning.  That's a lot of open water under sunny skies very early in the melt season.

The ice that is keeping this year's extent above 2016/2018 is being pushed into late season "kill zones" in the Greenland and Barents seas.

I'm watching the weather with considerable concern.
Title: Re: The 2019 melting season
Post by: epiphyte on May 15, 2019, 09:20:52 AM

The "Lift off" in the Chukchi is very concerning.  That's a lot of open water under sunny skies very early in the melt season.
 

Yup. Open water which isn't freezing, and which has passed the point at which fog/clouds are rapidly forming above it - so the surface air is already above the dewpoint. Laptev too.

This is Not Good At All.
Title: Re: The 2019 melting season
Post by: uniquorn on May 15, 2019, 02:29:27 PM
'On the ice' temperatures from whoi itp buoys. 4 of them reporting above zero temperatures recently. https://www.whoi.edu/page.do?pid=163197
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 15, 2019, 04:18:16 PM

It also looks like the melt of the Great Slave Lake is early. Watch for an early break up of the Mackenzie

Mackenzie has been flowing into the ocean the last few days. It is not super early, but it has begun.  The fast ice around the delta won't last long.

More interesting will be to watch the ice off the northern tip of alaska and see how it handles the wind over the next few days.
Title: Re: The 2019 melting season
Post by: Bruce Steele on May 15, 2019, 05:16:35 PM
Uniquorn, I always thought the buoy temperature was an internal temperature for the buoy. Because there is a electric motor that runs the profiler up and down wouldn't there also be some small amount of heat that affects the buoy temperature readings along with insolation during daylight hours?
Title: Re: The 2019 melting season
Post by: Sterks on May 15, 2019, 05:26:04 PM
'On the ice' temperatures from whoi itp buoys. 4 of them reporting above zero temperatures recently. https://www.whoi.edu/page.do?pid=163197
Just starting..
The EC shows 7 days of 24/7 warm air injection from the continent into the Arctic, thru Beaufort CAA and Chukchi. Beyond that, the hint is a warm Pacific side... The run below starts May 15, 00h, for 7 days.
Title: Re: The 2019 melting season
Post by: magnamentis on May 15, 2019, 06:45:52 PM

The "Lift off" in the Chukchi is very concerning.  That's a lot of open water under sunny skies very early in the melt season.
 

Yup. Open water which isn't freezing, and which has passed the point at which fog/clouds are rapidly forming above it - so the surface air is already above the dewpoint. Laptev too.

This is Not Good At All.

glad you mention dew point. it plays a huge role and is missing in most discussions, predictions and discussions about predictions. conditions falling below dew point is one of the negative feedbacks that plays a role in the last 3 years to doge the canonball.
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 15, 2019, 07:36:08 PM
These high pressure subsidence zones over the Arctic ocean put warm air over the ice and open water resulting in an thin inversion layer above the ocean. This time of year it gets constant light so thick fog or clouds don't form but it's humid. This situation maximizes uptake of solar heat and keeps outgoing longwave radiation low because the heat goes into melting ice and warming ice water. An extraordinary heat trap is developing over the arctic ocean as we speak. And water vapor - dew points near the air temperature - plays a role in reducing outgoing longwave radiation because it's a powerful greenhouse gas.
Title: Re: The 2019 melting season
Post by: anaphylaxia on May 15, 2019, 08:24:24 PM
Minor correction, the water vapour is always in the air absorbing long wave radiation. At the dew point it condenses, and makes mist, that is absorbent to the visible spectra, insulating against short wave radiation.
Title: Re: The 2019 melting season
Post by: uniquorn on May 15, 2019, 08:44:39 PM
Uniquorn, I always thought the buoy temperature was an internal temperature for the buoy. Because there is a electric motor that runs the profiler up and down wouldn't there also be some small amount of heat that affects the buoy temperature readings along with insolation during daylight hours?
Good point Bruce Steele. It is internal temperature and there is some insulation in the buoy so likely to be a time lag as it cools and warms. Buoy temperatures of -40C are not uncommon though so I think these can be seen as a reasonable guide to 'on the ice' temperatures at night.
Electric motor: no. That is on the profiler. A wheel runs it up and down the cable.
Insolation: yes. Likely to be warmer than ice surface temperature and/or air temperature during clear(ish) weather if it isn't covered in snow. A better estimate than the models we all use? I don't know. Should I stop posting them?

whoi tech here https://www.whoi.edu/page.do?pid=20777 but not a lot of detail about the buoy temperature sensor.
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 15, 2019, 08:53:10 PM
The light fog or thin low cloud situation is something that's in addition to the dewpoint being high. There is always water vapor, but in the Arctic water vapor pressure is often extremely low. Perhaps that's like a greenhouse with a translucent white plastic cover which acts as a light diffuser.
Title: Re: The 2019 melting season
Post by: Frivolousz21 on May 15, 2019, 10:18:14 PM
Both the Euro and the GFS go straight ham on the Arctic.

The process of the pattern changes already underway. 

During the next two to three days temperatures will still be relatively cool over most of the ice. 

however during this time a rigid high pressure will slowly be developing and spreading across the American Pacific side and into the Canadian basin.

By day three to four the ridge will be substantial and the cold air over 1/3 of the Artic will be scoured out completely with a very warm flow coming straight off the North American continent.

After day for this only intensify and slowly pivots to be more parallel with the Canadian basin.


Eventually spreading across Greenland
Title: Re: The 2019 melting season
Post by: Frivolousz21 on May 15, 2019, 10:29:04 PM
These are just random times next week to show the continuity of the major models with this.


That's absolutely filfthy for getting the Arctic melt season in full gear by June 1st over a large part of the basin.
Title: Re: The 2019 melting season
Post by: Neven on May 15, 2019, 11:18:30 PM
I have some analysis - nothing too spectacular - at the end of PIOMAS May 2019 (https://neven1.typepad.com/blog/2019/05/piomas-may-2019.html) that I've just posted on the ASIB. Two images below from that blog post, ECMWF weather forecast and Beaufort yesterday vs a week later in 2016:
Title: Re: The 2019 melting season
Post by: Niall Dollard on May 16, 2019, 12:22:19 AM
Neven is that our old friend "big block" (RIP) I spy at the top of the 2016 Beaufort image ?

 https://forum.arctic-sea-ice.net/index.php/topic,1493.msg83825.html#msg83825
Title: Re: The 2019 melting season
Post by: Pavel on May 16, 2019, 12:25:58 AM
The Beaufort looks awful but I'm afraid to see how the CAB ice will look in 7-10 days if there will be clear skies and above 0C temperatures. I can't imagine a worse weather pattern
Title: Re: The 2019 melting season
Post by: sark on May 16, 2019, 03:44:00 AM
Fast atmospheric response to a sudden thinning of Arctic sea ice

https://link.springer.com/article/10.1007/s00382-015-2629-7

Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 16, 2019, 04:44:09 AM
Should I stop posting them?

No, they are some of the best actual measurements!

conditions falling below dew point is one of the negative feedbacks that plays a role in the last 3 years to doge the canonball.


Indeed! Seems like this year things are starting to deteriorate from below, but the atmosphere is jealous and wants to play the biggest role.

Title: Re: The 2019 melting season
Post by: Aluminium on May 16, 2019, 07:08:38 AM
May 11-15.
Title: Re: The 2019 melting season
Post by: Jontenoy on May 16, 2019, 09:22:53 AM
Does anyone know where I can find the extra energy input / day (power) due to albedo change compared with 1900 or before due to reduced sea ice cover ?
Title: Re: The 2019 melting season
Post by: Rich on May 16, 2019, 09:56:21 AM
Does anyone know where I can find the extra energy input / day (power) due to albedo change compared with 1900 or before due to reduced sea ice cover ?

https://www.ncbi.nlm.nih.gov/m/pubmed/24550469/

Try this study. I think it concludes that the forcing equivalent associated with all (sea and land) lost Arctic albedo is equivalent to half of all athropogogenic CO2 emissions.
Title: Re: The 2019 melting season
Post by: gerontocrat on May 16, 2019, 11:09:40 AM
Does anyone know where I can find the extra energy input / day (power) due to albedo change compared with 1900 or before due to reduced sea ice cover ?

https://www.ncbi.nlm.nih.gov/m/pubmed/24550469/

Try this study. I think it concludes that the forcing equivalent associated with all (sea and land) lost Arctic albedo is equivalent to half of all athropogogenic CO2 emissions.

Quote from the article summary. Change in albedo 1979 to present equivalent to 25% of change in CO2. Also says  cloudiness -ve feedbacks of little importance.

Quote
Averaged over the globe, this albedo decrease corresponds to a forcing that is 25% as large as that due to the change in CO2 during this period, considerably larger than expectations from models and other less direct recent estimates.

Changes in cloudiness appear to play a negligible role in observed Arctic darkening, thus reducing the possibility of Arctic cloud albedo feedbacks mitigating future Arctic warming.

BUT.....in this reply the authors say that -ve feedback from increased cloudiness in the tropics outweighs albedo darkening in the Arctic.
https://www.pnas.org/content/111/21/E2157 
Arctic albedo changes are small compared with changes in cloud cover in the tropics
David R. Legates, Willis Eschenbach, and Willie Soon
Quote
Our point is that although Arctic changes may be important, they are small compared with the larger picture of changes in cloud cover in the tropics (Fig. 1). Although the change in total solar energy input is large in the Arctic over the 2000–2012 period, global solar energy input actually decreased by (−0.14 Wm−2), with a majority of the decrease resulting from the Southern Hemisphere (−0.26 Wm−2) rather than the Northern Hemisphere (−0.03 Wm−2). Thus, we argue against Pistone et al.’s (1) conclusion that Arctic darkening “is not offset by cloud albedo feedbacks.”

Also note that the Articles are from 2014. 5 years is a long time in climate science.

EDIT :Also data is up to around 2012 - well before the major change in sea ice in Antarctica starting in 2016
Title: Re: The 2019 melting season
Post by: Rich on May 16, 2019, 11:52:33 AM
Thanks for the clarification gerontocrat. I'm on a phone and reading the report again is difficult.

I would like to point out that we're not exactly pointing out the same metrics. The author points out the loss of albedo due to sea ice only as being 25% of the equivalent of CO2 emissions.

My post indicated an assumption of more lost albedo from land and sea sources. There is land in the Arctic which is also losing considerable albedo. It has been some time since I investigated this, so not sure where I might have gotten the idea that the loss of land based albedo was equivalent to the sea based.

As far as the age of the science...I'm just trying to provide something responsive for discussion. This was published 5 years ago. If you have something more recent, feel free to share. As you say, climate science is evolving...but I'm not aware of any new developments in the way albedo is calculated.
Title: Re: The 2019 melting season
Post by: Archimid on May 16, 2019, 12:11:15 PM

Arctic albedo changes are small compared with changes in cloud cover in the tropics
David R. Legates, Willis Eschenbach, and Willie Soon

Willie Soon of Heartland institute fame? I would be very careful with anything from that liar. I'm sure this paper is picking cherries or misleading in some significant way.
Title: Re: The 2019 melting season
Post by: Richard Rathbone on May 16, 2019, 12:18:32 PM
Its only considering the sunlit months (which is a problem with a lot of albedo analyses, not just this one). Open sea emits more radiation to space than ice covered sea in autumn and winter, so the effect on the average planetary energy balance over the entire year is a lot less.
Title: Re: The 2019 melting season
Post by: MA Rodger on May 16, 2019, 01:12:55 PM
Concerning
'Legates, Eschenbach & Soon (2014) Arctic albedo changes are small compared with changes in cloud cover in the tropics'( https://www.pnas.org/content/pnas/111/21/E2157.full.pdf (https://www.pnas.org/content/pnas/111/21/E2157.full.pdf) ):

All three are well-konwn climate denialists. Their paper has been cited just the once, by Plistone et al (2014) ( https://www.pnas.org/content/111/21/E2159 ). The citation is made by the same authors which the denialists criticised and was made purely to allow the debunking the denialist claims.
Title: Re: The 2019 melting season
Post by: Alphabet Hotel on May 16, 2019, 01:29:44 PM

Willie Soon of Heartland institute fame? I would be very careful with anything from that liar. I'm sure this paper is picking cherries or misleading in some significant way.

David Legates is affiliated with the Heartland Institute as well:

https://www.heartland.org/about-us/who-we-are/david-legates
Title: Re: The 2019 melting season
Post by: AmbiValent on May 16, 2019, 02:32:54 PM
By eyeballing, floe size in the Beaufort seems smaller than in 2016, which would be bad for the ice. But is there an official account of this?
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 16, 2019, 04:13:28 PM
Rich wrote:
Quote
The author points out the loss of albedo due to sea ice only as being 25% of the equivalent of CO2 emissions.
My 'take home' from this is that, within the Arctic, CO2 is going up and albedo is going down, so ice loss will accelerate.
Title: Re: The 2019 melting season
Post by: Tealight on May 16, 2019, 05:03:28 PM
Now in mid-May, we are just over a month away from peak insulation. The time the northern hemisphere has it's greatest warming potential. Including Greenland, snow cover extent is still around 50% more than sea ice extent. From an overall albedo perspective this makes sea ice look less relevant than snow cover. At this time 2012 dived to record low snow extent in June and attacked the ice from all sides with continental heat to force widespread meltponding and eventual record low sea ice extent.

This year seems to have pretty average snow cover more in line with 2015 and 2016, but below 2017 and 2018.
Title: Re: The 2019 melting season
Post by: Ken Feldman on May 16, 2019, 06:15:48 PM
Does anyone know where I can find the extra energy input / day (power) due to albedo change compared with 1900 or before due to reduced sea ice cover ?

https://www.ncbi.nlm.nih.gov/m/pubmed/24550469/

Try this study. I think it concludes that the forcing equivalent associated with all (sea and land) lost Arctic albedo is equivalent to half of all athropogogenic CO2 emissions.

If you put the title of the study into a search engine, you can find other more recent studies that cite it as a reference.  Here's a 2019 study that looks at how clouds moderate the impact of the loss of sea ice.

https://www.mdpi.com/2073-4433/10/1/12 (https://www.mdpi.com/2073-4433/10/1/12)

Quote
Atmosphere 2019, 10(1), 12; https://doi.org/10.3390/atmos10010012

How Much Do Clouds Mask the Impacts of Arctic Sea Ice and Snow Cover Variations? Different Perspectives from Observations and Reanalyses

Anne Sledd * and Tristan L’Ecuyer

Quote
Decreasing sea ice and snow cover are reducing the surface albedo and changing the Arctic surface energy balance. How these surface albedo changes influence the planetary albedo is a more complex question, though, that depends critically on the modulating effects of the intervening atmosphere. To answer this question, we partition the observed top of atmosphere (TOA) albedo into contributions from the surface and atmosphere, the latter being heavily dependent on clouds. While the surface albedo predictably declines with lower sea ice and snow cover, the TOA albedo decreases approximately half as much. This weaker response can be directly attributed to the fact that the atmosphere contributes more than 70% of the TOA albedo in the annual mean and is less dependent on surface cover. The surface accounts for a maximum of 30% of the TOA albedo in spring and less than 10% by the end of summer. Reanalyses (ASR versions 1 and 2, ERA-Interim, MERRA-2, and NCEP R2) represent the annual means of surface albedo fairly well, but biases are found in magnitudes of the TOA albedo and its contributions, likely due to their representations of clouds. Reanalyses show a wide range of TOA albedo sensitivity to changing sea ice concentration, 0.04–0.18 in September, compared to 0.11 in observations.

Quote
The reduced sensitivity of TOA albedo to surface cover is important for the ice-albedo feedback.  Our work supports previous studies that have found reduced ice-albedo feedback parameters due to clouds [17,18]. We have found that clouds mask the surface albedo and damp changes in surface cover at the TOA. When the surface albedo is sensitive to SIC changes in the summer and fall, the surface contribution to the TOA albedo is low, leading to reduced changes at the TOA. There is nuance, though.  Clouds do not simply replace underlying snow and ice. While clouds have higher albedos than open  ocean, there is still a measurable difference (0.15) in TOA albedo between land with and without snow cover and ocean with and without sea ice cover. Clouds may reduce the ice-albedo feedback, but the radiative effects of clouds at the TOA are unlikely to be large enough to prevent the ice-albedo feedback from continuing and contributing to Arctic amplification.
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 16, 2019, 06:42:38 PM
Willie Soon and Lindzen, both deniers, have been wildly wrong about the effects of tropical clouds and the planetary energy balance. There have been many recent papers on clouds in the tropics and subtropics that debunked their theories.
Title: Re: The 2019 melting season
Post by: binntho on May 16, 2019, 07:10:34 PM
This year seems to have pretty average snow cover more in line with 2015 and 2016, but below 2017 and 2018.

The graph you included shows this year compared to 2012 - I assume. If that is the case, to me this year does not look significantly different re. snow cover.
Title: Re: The 2019 melting season
Post by: gerontocrat on May 16, 2019, 08:10:13 PM
Willie Soon and Lindzen, both deniers, have been wildly wrong about the effects of tropical clouds and the planetary energy balance. There have been many recent papers on clouds in the tropics and subtropics that debunked their theories.
Trust no-one - I was fooled because their letter was in the Proceedings of The National Academy of Sciences, USA. Bummer

Title: Re: The 2019 melting season
Post by: jai mitchell on May 16, 2019, 08:38:44 PM
Thankfully, there is a separate thread for albedo discussion!

https://forum.arctic-sea-ice.net/index.php?topic=1749.msg199578#msg199578

Rich wrote:
Quote
The author points out the loss of albedo due to sea ice only as being 25% of the equivalent of CO2 emissions.
My 'take home' from this is that, within the Arctic, CO2 is going up and albedo is going down, so ice loss will accelerate.
Title: Re: The 2019 melting season
Post by: Shared Humanity on May 16, 2019, 09:00:45 PM
Thankfully, there is a separate thread for albedo discussion!

https://forum.arctic-sea-ice.net/index.php?topic=1749.msg199578#msg199578


 :)
Title: Re: The 2019 melting season
Post by: Archimid on May 16, 2019, 10:54:54 PM
Trust no-one - I was fooled because their letter was in the Proceedings of The National Academy of Sciences, USA. Bummer

I don't doubt that there is useful science in that paper, but there is deception there somewhere.
Title: Re: The 2019 melting season
Post by: magnamentis on May 17, 2019, 01:32:42 AM
quite an outlook, only remaing cool spot is where the ice will be gone by the end of the meilting season anyways.

Bad for now and even worse for later this summer, at least most probably so.
Title: Re: The 2019 melting season
Post by: epiphyte on May 17, 2019, 05:52:43 AM
By eyeballing, floe size in the Beaufort seems smaller than in 2016, which would be bad for the ice. But is there an official account of this?

Don't think so - but for the past few years some of us have been calling it out as 'granularity', and subjectively, yes, the total perimeter of the ice/water interface has been heading steadily toward fractal territory for quite some time now.

And yes, Pretty soon we'll be in Margaritaville at four in the morning on an off-night.

 
Title: Re: The 2019 melting season
Post by: pauldry600 on May 17, 2019, 10:25:44 AM
Theres a lot of dangerous stuff going on this year up there.

Will this be the year that shouts "hey world look at me now"
Title: Re: The 2019 melting season
Post by: JayW on May 17, 2019, 11:47:49 AM
60 hour loop of the Beaufort. May 14 12Z  - May 17 0Z.
 (Requires a click)

Second attachment is the ECMWF forecast. The tight pressure gradient north of Alaska is progged to persist another 5 days or so, resulting in 20-30 knot easterly winds.
Title: Re: The 2019 melting season
Post by: uniquorn on May 17, 2019, 12:41:21 PM
The whole Arctic pack is rotating clockwise now. The ice has transform faults all around the CAA and Greenland. Faults are continuous in ice on the north of Ellesmere island on today's Aqua image.
A bit of a 'hill start' but ice north of caa definitely joining the rotation now.
Worldview terra modis may10-16. https://go.nasa.gov/2EinfAu
Title: Re: The 2019 melting season
Post by: bbr2314 on May 17, 2019, 03:21:18 PM
Theres a lot of dangerous stuff going on this year up there.

Will this be the year that shouts "hey world look at me now"
The world won't notice or care about the Arctic sea ice any more than it has since 2012. But, they will notice and care about the worsening disasters that happen due to the accelerating collapse of the three-cell system. I would expect epic floods, heatwaves, cyclones, and blizzards as we enter the peak of summer and drift into autumn and early winter, with new extremes set in many locations (mostly hot, many wet, many dry, some cold, some snowy).
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 17, 2019, 03:29:35 PM
As the thick multiyear ice disappears the Arctic ocean is becoming more like a blended Margarita with every passing year. The big chunks in the Lincoln sea pulverize when they enter the Nares strait and the Beaufort rapidly clears up as the thin fine ice rapidly melts away while the larger pieces move rapidly away from the Mackenzie delta. Slowly but surely more heat is getting into Arctic waters to melt the bottom out when upwelling gets going under persistent high pressure situations like we're seeing now.

However, the thin ice also lets more heat escape to the Arctic atmosphere than the thick ice did. This may allow cooling of the fresh upper water layer under the Beaufort high. I don't know if the low heat anomaly in the Beaufort sea in the image below is real, but it could be and the accumulation of cold fresh water there would explain it. Note the high heat content of Atlantic waters entering the Arctic.

Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 17, 2019, 03:57:03 PM
Theres a lot of dangerous stuff going on this year up there.

Will this be the year that shouts "hey world look at me now"

No chance. No one cares. No one gets it. The establishment has convinced everyone that problem is a meter of sea level rise over the course of a century and a 2 C temp increase. Those 2 issues are not that intuitively scary. The public at large has no comprehension of weather patterns and the part that the ice caps play in the zoomed out system. (A picture of santa drowning Titanic Jack style might help a little though.)

BUT, I do think this will be the year that people who do follow this situation (like on this forum) and who think that the BOE isn't happening til 2030 will shout, "OOPS".

Weak, thin ice detached from fast ice and slushing about around the entire arctic shore is kind of hard to ignore in mid may. 5 weeks til peak insolation, 10 weeks til less insolation, and 17 weeks more of melt. Hard to believe the ice is going to hold up.

My prediction for the season is Ice Island rather than BOE. Which will probably set up 2020 for BOE.  Could be "beautifully" coinciding with Trumps reelection. 
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 17, 2019, 04:14:38 PM
The short term forecast for the Mackenzie watershed is crazy. It has been warm and will continue to heat up for the next 4 days until the as far north as the delta is around 20C. (The models actually show it getting even worse later next week, but I'm going to ignore 5-10 day forecasts.) In the next week we will witness a epic blowout of the fast ice surrounding the Mackenzie Delta.
Title: Re: The 2019 melting season
Post by: magnamentis on May 17, 2019, 07:57:39 PM
By eyeballing, floe size in the Beaufort seems smaller than in 2016, which would be bad for the ice. But is there an official account of this?

Don't think so - but for the past few years some of us have been calling it out as 'granularity', and subjectively, yes, the total perimeter of the ice/water interface has been heading steadily toward fractal territory for quite some time now.

And yes, Pretty soon we'll be in Margaritaville at four in the morning on an off-night.

this granularity sees to some "fake extent" IMO. while granular ice can keep a very large area covered, at one time in the future the wolf in sheep clothes shall show his true face.

no clue when, why (trigger event) or how, but for years i see some nasty kind of widely spread sudden death of the sea-ice and this time possibly without extremely strong and long cyclone or any of the other extreme events, simply because ice got so thin and dispersed.
Title: Re: The 2019 melting season
Post by: Carex on May 17, 2019, 08:40:22 PM
Just a quick note on peripheral ice.  The Great Lakes Coastal Watch (NOAA) as of yesterday show no ice on the Great Lakes.  The last holdouts in Thunder, Black, and Nipigon Bays on the north shore of Lake Superior have faded away. (I couldn't see anything on MODIS on the 13th but it was partly cloudy).
Title: Re: The 2019 melting season
Post by: uniquorn on May 17, 2019, 09:58:54 PM
Comparison of 2019 and 2016 using unihamburg amsr2-uhh, mar20-may16, pacific side.
Some concentration data has been sacrificed during processing so this should only be seen as a guide. Some days are missing data
Title: Re: The 2019 melting season
Post by: Neven on May 17, 2019, 10:17:09 PM
60 hour loop of the Beaufort. May 14 12Z  - May 17 0Z.
 (Requires a click)

Houston, we have lift-off.  :o
Title: Re: The 2019 melting season
Post by: oren on May 17, 2019, 10:28:18 PM
60 hour loop of the Beaufort. May 14 12Z  - May 17 0Z.
 (Requires a click)
Besides the impressive movement, some of the slush between the bigger floes is definitely melting and shrinking, unless my eyes are deceiving me.
Title: Re: The 2019 melting season
Post by: Shared Humanity on May 17, 2019, 11:22:59 PM
60 hour loop of the Beaufort. May 14 12Z  - May 17 0Z.
 (Requires a click)
Besides the impressive movement, some of the slush between the bigger floes is definitely melting and shrinking, unless my eyes are deceiving me.

It was abnormally warm over Alaska for much of the winter. Going to melt quickly, I think.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 17, 2019, 11:26:54 PM
Just something I like looking at to help visualize the loss.

I try to download the image daily. On days I miss, I just double the duration of the previous day's frame.
Title: Re: The 2019 melting season
Post by: magnamentis on May 17, 2019, 11:31:17 PM
Just something I like looking at to help visualize the loss.

I try to download the image daily. On days I miss, I just double the duration of the previous day's frame.

try this:

https://kuroshio.eorc.jaxa.jp/JASMES/daily/polar/index.html?date=&prod=SIC&area=NP&sensor=MOD

more choices and data are backwards available, further the resolution is way higher, more details shown to geht the impression that you're looking for.
Title: Re: The 2019 melting season
Post by: Sterks on May 18, 2019, 12:06:53 AM
60 hour loop of the Beaufort. May 14 12Z  - May 17 0Z.
 (Requires a click)

Houston, we have lift-off.  :o
Or positive rate, as jet pilots say.
The Beaufort still has a week of climbing
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 18, 2019, 02:29:34 AM
60 hour loop of the Beaufort. May 14 12Z  - May 17 0Z.
 (Requires a click)
Besides the impressive movement, some of the slush between the bigger floes is definitely melting and shrinking, unless my eyes are deceiving me.

It was abnormally warm over Alaska for much of the winter. Going to melt quickly, I think.

The next week is going to be very warm, a bit windy, and reasonably sunny in the Beaufort...so the melt of the slushy ice is going to happen quite soon indeed.

The snow cover near Beaufort wont last the week, so late May sun could have the whole area really baking super hot by June.
Title: Re: The 2019 melting season
Post by: Aluminium on May 18, 2019, 07:45:41 AM
May 13-17.

Ice is disintegrating in the Beaufort. A strong anticyclone and positive temperatures will be according to forecast. There is max temperature in the last image.
Title: Re: The 2019 melting season
Post by: gerontocrat on May 18, 2019, 12:01:27 PM
There is max temperature in the last image.
A quibble...

I think I am right in saying that the GFS maximum (and minimum) temperature images are a bit deceiving, in that even if the forecast is 100% correct, there will not be a date/time when the image is a reality.

For the 5 day image shown, I think the image shows the maximum temperature for each element of the grid over the next 5 days. So one place might be at maximum today, another in 3 days time, and so on.  You can tell this from the image. Alaska cannot be at maximum temperature at the same time as Norway - if Alaska is basking in the late afternoon sun, Norway is freezing in the early early hours before dawn.

Thus the maximum image exaggerates the heat, the minimum image exaggerates the cold.

Mind you, it still looks like the Central Arctic sea ice is on the move and in serious grief..
Title: Re: The 2019 melting season
Post by: Aluminium on May 18, 2019, 01:08:12 PM
I think I am right in saying that the GFS maximum (and minimum) temperature images are a bit deceiving, in that even if the forecast is 100% correct, there will not be a date/time when the image is a reality.
Of course. Almost every point in the Central Arctic will reach zero at least once in 5 days but not simultaneously. The average is a few degrees lower.
Title: Re: The 2019 melting season
Post by: be cause on May 18, 2019, 01:13:11 PM
  This time last year I think it was Uniquorn who posted a gif entitled '233 days of anti-transpolar drift' .. the last 233 days has mostly been the opposite .
 All forecasts are for another week of ideal conditions for ice loss . Either the winds or the temperatures would be enough to deepen the threat of accelerated melt .. but both at this time of year .. I have not seen before.
  Never has the ice been more mobile .. every change in wind direction , even locally , causes a change in ice movement .. and a warm welcome awaits in Barnetz , Fram and Nare's for much or it .
  This is a very different year to last .. if the weather continues to suit export and melt we will be re-writing the records .. b.c.
 
 
Title: Re: The 2019 melting season
Post by: Trebuchet on May 18, 2019, 07:44:52 PM
 The only bright spot is that the Siberian sector is still holding up. Looking at worldview, surface melt began here in 2012 around 11th of May. Maybe that extra 50cm of snow on the ground is making a difference.
Title: Re: The 2019 melting season
Post by: magnamentis on May 18, 2019, 09:15:07 PM
The only bright spot is that the Siberian sector is still holding up. Looking at worldview, surface melt began here in 2012 around 11th of May. Maybe that extra 50cm of snow on the ground is making a difference.

what holds and what doesn't at this early stage is due to winds, air and water currents as well as (even mainly) weather patterns.

if the winds of example blow from the pacific to the atlantic side and the currents do the same and the weather is accordingly a specific region can even refreeze and/or compact.

the siberian sector was very early to open this year and now has mostly closed again due to above mentioned mechanisms.

it means not much because it will melt either way 99% and the snow cover only starts to play a role once it exists instead of zero snow. 50cm of snow produce similar temps and albedo like 1 meter of snow, only that it takes a bit longer to melt 1m but not even that, depending on weather, is necessarily the case.

i've seen 10cm of snow hold for weeks and i've seen 3 meters of snow go within the number of weeks.
Title: Re: The 2019 melting season
Post by: jdallen on May 19, 2019, 05:11:03 AM
May 13-17.

Ice is disintegrating in the Beaufort. A strong anticyclone and positive temperatures will be according to forecast. There is max temperature in the last image.

... and an abrupt end to snow cover.

On the ice, melt will definitely lead to ponding, even if there is still slushy snow cover on top of it.
Title: Re: The 2019 melting season
Post by: Frivolousz21 on May 19, 2019, 06:12:32 AM
I just looked at the 12z European weather model and it is unbelievable or the Arctic Basin to end out May. 

if you go back in historical records probably even back to the 1850s or 60s which is 160 or 70 years.
You will be hard-pressed to find even one year showing it kind averaging syncing are anomalies sunny skies that the weather models are showing and it's not just a fantasy because we were well under way of the pattern change as I say this.



Starting with the classic banana high pressure with the cutoff vortex over Eastern Canada transitioning to a basin wide Mega high pressure in the long range that is nasty Sunshine for this time of year.

That leads to the possibility by June 1st.  We will see surface melting Albedo drops that we've never seen on record before.

Men as you all know because of that and heading towards Peak solar insolation in late June there will be a ramp-up and Ice loss we could be looking at something that blows 2007 out of the water.


I know 2012 had a lower minimum than 2007.

But 2007 had an UNPRECEDENTED ALMOST CENTRAL ARCTIC BASIN NUKE.

THIS IS LOOKING LIKE A DRESDEN FIREBOMBING THAT COMPLETELY DECIMATES THE ENTIRE BASIN WITH TIME


Title: Re: The 2019 melting season
Post by: jdallen on May 19, 2019, 08:42:20 AM
I just looked at the 12z European weather model and it is unbelievable or the Arctic Basin to end out May. 
<snippage>
I don't have Friv's skill at hyperbole, but looking at GFS,  most of the snow cover on the Pacific side of the basin, on and off the ice, is modeled to disappear over the next 5 days.  It only gets worse at the end of the model run.

So, massive drop in albedo, creation of melt ponds over exactly the ice (Beaufort, Chukchi, ESS) that will bear the brunt of the pounding by sunshine that's coming.
Title: Re: The 2019 melting season
Post by: El Cid on May 19, 2019, 09:17:19 AM
I decided to do a comparison of SLP for the month of May. I looked at a couple of years and show here 2019 May (so far), 2018, 2016, 2007. Given the forecast, the extreme high pressure seems truly epic
Title: Re: The 2019 melting season
Post by: Neven on May 19, 2019, 10:28:12 AM
Remember, there's a 2016 melting season thread, and reading all the comments around this time of year, is a good way to compare to what's happening now. Here (https://forum.arctic-sea-ice.net/index.php/topic,1493.msg77424.html#msg77424), for instance, I posted the 6-day forecast, and though bad for the ice, especially given how open the Beaufort already was by that time, the current forecast is worse, especially the coming three days (pressure is much higher, for instance).

But given how it has been so far, I would venture to say that things look slightly less bad from day 4-6 (and beyond that looks even better for the ice). I just hope that we don't get to see this kind of set-up during June or July, because like friv says, a 2007-type event would obliterate the ice pack.
Title: Re: The 2019 melting season
Post by: sark on May 19, 2019, 10:43:42 AM
I decided to do a comparison of SLP for the month of May. I looked at a couple of years and show here 2019 May (so far), 2018, 2016, 2007. Given the forecast, the extreme high pressure seems truly epic

You'd have to allow somehow for the stratosphere/troposphere coupling at final warming.  May won't look normal because the polar cell split in two.  Although it also did it in April, March, February, January, and November, and in 2017, 2016, 2014, etc etc.

It's more split than not at this point.  This should not be happening in the second half of May
Title: Re: The 2019 melting season
Post by: Neven on May 19, 2019, 11:20:50 AM
It's only when you combine both SLP (sea level pressure average) and SAT (surface air temperature anomaly), that you see how exceptional May has been so far. 2010 and 2016 come close, 2017 was even worse SLP-wise (temps were much lower), but 2019 takes the cake.
Title: Re: The 2019 melting season
Post by: Neven on May 19, 2019, 11:51:51 AM
I don't have Friv's skill at hyperbole, but looking at GFS,  most of the snow cover on the Pacific side of the basin, on and off the ice, is modeled to disappear over the next 5 days.  It only gets worse at the end of the model run.

So, 2019 is leading when it comes to the SAT/SLP combo, compared to 2010 and 2016, but it's behind when it comes to snow. For now. If the 2019 trend line manages to go as low as those other two years in weeks to come, things will start to look bleak (even though the ground won't).

Here's a close-up from the NOAA/NESDIS multisensor (https://www.star.nesdis.noaa.gov/smcd/emb/snow/HTML/snow.htm) snow cover graph:
Title: Re: The 2019 melting season
Post by: bbr2314 on May 19, 2019, 12:11:44 PM
I don't have Friv's skill at hyperbole, but looking at GFS,  most of the snow cover on the Pacific side of the basin, on and off the ice, is modeled to disappear over the next 5 days.  It only gets worse at the end of the model run.

So, 2019 is leading when it comes to the SAT/SLP combo, compared to 2010 and 2016, but it's behind when it comes to snow. For now. If the 2019 trend line manages to go as low as those other two years in weeks to come, things will start to look bleak (even though the ground won't).

Here's a close-up from the NOAA/NESDIS multisensor (https://www.star.nesdis.noaa.gov/smcd/emb/snow/HTML/snow.htm) snow cover graph:

I would be curious as to what % of this year's coverage is functionally useless for maintaining Arctic cold. There is a LOT of snow remaining and still falling over high mountains south of 50N (Rockies, Hinalayas, Alps). I think this may actually be partially to blame for the worsening conditions in the far north as the anomalous snow cover encourages -500MB anomalies down south, affecting all the oceanic heat up north.

LR forecasts have northern Russia melting out entirely soon, Canada will follow as well, so I could see our current arrangement worsening further as we head into June.
Title: Re: The 2019 melting season
Post by: meddoc on May 19, 2019, 12:52:47 PM
Already, a lot of blue in the Beaufort, Kara, ESS on arctic explorer.
I'd say- maybe only due to the clearer Skies, thanks to HP- the Beaufort looks like Toast.
If that fragmented Slush melts out completely before Solstice, it's gonna be a Scorcher for the whole Pack.
Title: Re: The 2019 melting season
Post by: gerontocrat on May 19, 2019, 01:59:42 PM
OK, so the snow is melting. This happens at this time of year.

18th May:-
In North America both SCE - Snow Cover Extent and SWE - Snow Water Equivalent ( = mass) are just under +1 SD, i.e. a tad above average.
In Eurasia,  both SCE - Snow Cover Extent and SWE - Snow Water Equivalent ( = mass) are above +1 SD, i.e. considerably above average.

It will quickly disappear as is normal.

https://ccin.ca/ccw/snow/current
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 19, 2019, 02:37:30 PM
Already, a lot of blue in the Beaufort

I assume you are referring to open water? However melt ponds are starting to become visible in the Beaufort Sea as well:

https://go.nasa.gov/2Ej6gxQ
Title: Re: The 2019 melting season
Post by: JayW on May 19, 2019, 03:32:52 PM
 60s hour loop of the Kara Sea. May 16, 22Z - May 19, 9Z.  The winds appear to be shifting in the most recent frames, likely leading to less sea ice loss in the coming days for this area, just the slush getting moved around.

http://rammb-slider.cira.colostate.edu/?sat=jpss&z=3&im=12&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=1&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=northern_hemisphere&p%5B0%5D=band_i02&x=13555.5&y=12655.5556640625

Second attachment is Kara Sea ice area.
Title: Re: The 2019 melting season
Post by: JayW on May 19, 2019, 08:06:47 PM
I'd wager that it rained in that yellow area near the center.

Title: Re: The 2019 melting season
Post by: jdallen on May 19, 2019, 08:55:13 PM
OK, so the snow is melting. This happens at this time of year.
<snipage>
It will quickly disappear as is normal.

https://ccin.ca/ccw/snow/current
Yes, I completely understand that.  I'm not trying to suggest snow cover overall is somehow significant.

It's *where* its being lost, combined with the ice conditions and up-coming weather conditions that concerns me.

It's what this specific region being hammered now portends for the next two months.

(Image credit - Climate Reanalyzer https://climatereanalyzer.org/wx/fcst/#gfs.arc-lea.snowd-mslp)
Title: Re: The 2019 melting season
Post by: uniquorn on May 19, 2019, 10:10:36 PM
ascat and uni-hamburg amsr2-uhh (both heavy contrast) overlaid onto mercator 34m salinity. Ascat showing approximate ice age, amsr2 showing more fracture detail. Salinity somewhat lost under the other 2 layers but reddy brown is salltier than greeny yellow saltier than blue. sep24-may18.
Note the incoming weather event from the pacific on day117(0427)
tricky to get the scaling and overlay to match up. The ice matches better than the lat/long lines


Title: Re: The 2019 melting season
Post by: Sterks on May 19, 2019, 11:23:56 PM
OK, so the snow is melting. This happens at this time of year.
Yeah, and the same happens with sea ice, and with the frost in my freezer if I unplug it.
Dumbest thing I read, your entire comment.

 Should we then close the thread and talk about football? Come on, ice is gonna melt, more or less who knows, who cares, hey its freaking normal in summer!!

How snow melts out in May and June, on continents and on ice, is relevant to what’s gonna happen to ice, be it causality or correlation, and I pay good attention to it.
Title: Re: The 2019 melting season
Post by: Viggy on May 20, 2019, 12:32:11 AM
OK, so the snow is melting. This happens at this time of year.
Yeah, and the same happens with sea ice, and with the frost in my freezer if I unplug it.
Dumbest thing I read, your entire comment.

 Should we then close the thread and talk about football? Come on, ice is gonna melt, more or less who knows, who cares, hey its freaking normal in summer!!

How snow melts out in May and June, on continents and on ice, is relevant to what’s gonna happen to ice, be it causality or correlation, and I pay good attention to it.

Calma there buddy! I think you are reading Gerontocrat's comment with some weird lenses on.
Title: Re: The 2019 melting season
Post by: sark on May 20, 2019, 01:02:00 AM
This snow is melting comment and objection is an annual tradition.  I just kind hope something structurally changes in week 3 because currently we're in trouble for repeating it next year.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 20, 2019, 03:30:42 AM
OK, so the snow is melting. This happens at this time of year.
Yeah, and the same happens with sea ice, and with the frost in my freezer if I unplug it.
Dumbest thing I read, your entire comment.

 Should we then close the thread and talk about football? Come on, ice is gonna melt, more or less who knows, who cares, hey its freaking normal in summer!!

How snow melts out in May and June, on continents and on ice, is relevant to what’s gonna happen to ice, be it causality or correlation, and I pay good attention to it.

Calma there buddy! I think you are reading Gerontocrat's comment with some weird lenses on.

If everyone could kindly STFU. The Arctic Sea Ice Melting Season 2019 is actually really interesting. Off-topic or irrelevant comments and gripes can be quite easily ignored.


There are currently some fires in northern alberta and maybe the northwestern territories. The smoke is headed towards the caa currently, although it is difficult to tell where it will go in the coming days. If it does end up settling on ice or thick snow, it could really supercharge melt.

A huge amount of open water has opened up in the northern part of baffin. HUGE. Thus the ice that is there is much further south than normal, which pretty much guarantees that baffin melt will stay considerably ahead of schedule.

Most interestingly, the heatwave in the Mackenzie river basin is INTENSE. Starting tomorrow temps are supposed to reach 15C, and then things really start to heat up for the next few days. The permafrost in the area could have a really really bad year.
Title: Re: The 2019 melting season
Post by: Aluminium on May 20, 2019, 07:26:06 AM
May 15-19.
Title: Re: The 2019 melting season
Post by: ReverendMilkbone on May 20, 2019, 07:41:03 AM
May 15-19.

So, is that dark patch just up from the pole melt ponds? 

JayW claimed it was from rain in post 892

This is getting ugoolee.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 20, 2019, 08:10:53 AM
I asked myself the same question ReverendMilkbone.
Title: Re: The 2019 melting season
Post by: Rich on May 20, 2019, 09:06:28 AM
That must be rain.

I zoomed in on some of the darker reference points (melt ponds ?) that existed before the "rain" passed over and could still discern their unique outline through the new shadow.

Process of elimination....what else could it be?
Title: Re: The 2019 melting season
Post by: Eco-Author on May 20, 2019, 03:38:24 PM
It seems recent 'losses' in the barrent sea is as much due to the ice being 'pushed' north towards the pole as it is with melt.  Note the absence of ice on the north side of these islands which shows ice being pushed around to the north!  Also, global ice has remained noticeably below the line which should make for a slightly warmer planet overall/affect even the ice more in the north?  I've not seen any references to above average sea surface temps in a while and I'm not all that trusting of Nullschool on this matter... 
Title: Re: The 2019 melting season
Post by: Eco-Author on May 20, 2019, 04:28:20 PM
With the recent heatwave in Scandinavia, not to mention the post up-thread of that Russian Island in the arctic with the glacier that's moving like 10X faster and can contribute to a FOOT of sea level rise, I have to wonder why only Greenland melt seems to be reported on which isn't nearly enough as it is...  Haven't we also witness glaciers in Norway that have drastically sped up???  Are their any pages you'd recommend to keep track of these?  Get a rain bomb like Harvey hitting a glacier and the ice hardly needs to melt to be washed out to sea and effect sea level practically overnight :(
Title: Re: The 2019 melting season
Post by: Eco-Author on May 20, 2019, 04:39:58 PM
This is 250mb for today.  It seems new this year (?) to see this level of the jet acting more like we'd expect of the 500mb level... with so many cyclone like systems that seem to be acting like cogs in a wheel allowing the warmth just to jump on the fastest track north!  We also see for the first time the DMI being above the average line (for the most part) in late spring, vs. its more normal at or below average for this year.  Seems to me that because the states are a bit cooler and the arctic a bit warmer, the temp difference is what is allowing the jet to slow and allow this greater than average heat transfer north?!!
Title: Re: The 2019 melting season
Post by: be cause on May 20, 2019, 05:14:25 PM
With the recent heatwave in Scandinavia, not to mention the post up-thread of that Russian Island in the arctic with the glacier that's moving like 10X faster and can contribute to a FOOT of sea level rise, I have to wonder why only Greenland melt seems to be reported on which isn't nearly enough as it is...  Haven't we also witness glaciers in Norway that have drastically sped up???  Are their any pages you'd recommend to keep track of these?  Get a rain bomb like Harvey hitting a glacier and the ice hardly needs to melt to be washed out to sea and effect sea level practically overnight :(



 What is needed is someone with the interest and skill set to bring the data here , Gerontocrat and co. can only do so much ! Perhaps you are the person to provide the information you feel is lacking ? .. b.c.
Title: Re: The 2019 melting season
Post by: Eco-Author on May 20, 2019, 05:24:51 PM
With the recent heatwave in Scandinavia, not to mention the post up-thread of that Russian Island in the arctic with the glacier that's moving like 10X faster and can contribute to a FOOT of sea level rise, I have to wonder why only Greenland melt seems to be reported on which isn't nearly enough as it is...  Haven't we also witness glaciers in Norway that have drastically sped up???  Are their any pages you'd recommend to keep track of these?  Get a rain bomb like Harvey hitting a glacier and the ice hardly needs to melt to be washed out to sea and effect sea level practically overnight :(

What is needed is someone with the interest and skill set to bring the data here , Gerontocrat and co. can only do so much ! Perhaps you are the person to provide the information you feel is lacking ? .. b.c.

To me, all I'm saying is even if just one remote island we've never even heard of can and WILL contribute a FOOT to sea level rise seems to be something that should be a lot more on our radars!  I think I was being conservative with 10X faster glacier flow as the post up thread was ASTONISHING!  Extreme rosby waves will indeed bring heavy rains to these glaciers and flush them out to sea long before they've had time to melt :(  a foot alone would be intolerable! 

Um... I was wondering to myself about the melt of permafrost too... won't this also contribute to sea level rise??
Title: Re: The 2019 melting season
Post by: oren on May 20, 2019, 05:29:52 PM
Not everything belongs on the 2019 melting season thread. Many of these subjects you raise are mentioned elsewhere in the forum.
Title: Re: The 2019 melting season
Post by: stjuuv on May 20, 2019, 07:15:49 PM
To me, all I'm saying is even if just one remote island we've never even heard of can and WILL contribute a FOOT to sea level rise seems to be something that should be a lot more on our radars!
Where did you get the foot of sea level rise figure for the Vavilov glacier from? With a total ocean surface area of about 361 million square kilometers, a foot (0.3 meters) of sea level rise requires a total volume of about 100,000 cubic kilometers of glacier ice to melt. That figure would require the ENTIRE October Revolution Island to be covered by an average of 7 kilometers of ice or the Vavilov glacier to have 50+km of ice thickness, which is hardly the case.

A foot of sea level rise sounds more like total sea-level rise potential for ALL glaciers and ice caps outside the ice sheets of Antarctica and Greenland - see here: https://phys.org/news/2018-09-unprecedented-ice-loss-russian-cap.html

See more here: https://web.archive.org/web/20071216235037/http://www.grida.no/climate/ipcc_tar/wg1/412.htm#tab113
Quote
Antarctic ice sheet - 25.71 million cubic kilometers (up to about 200 feet of sea level rise)
Greenland ice sheet - 2.85 million cubic kilometers (up to about 24 feet of sea level rise)
All other glaciers and ice caps combined - 0.22 million cubic kilometers (up to about 2 feet of sea level rise)
Title: Re: The 2019 melting season
Post by: be cause on May 20, 2019, 07:50:22 PM
on cue the high pressure and descending warm air are providing clear skies today over much of the Arctic basin . Worldview is beginning to reveal the unfolding disintergration of the ice . Things look in a much worse state now than in mid June last year . The fracture zones running from Beaufort to the pole show the true state of the vast majority of the ice in the basin .. ready for dispersal and melt .
  The open water showing in these fractures may be what others are seeing as rain or melt pond effects . The warmth expected over the next week may see open water around the pole even before melt season proper has begun .
 I was hoping that GFS was running away with their heat forecast as they did over the last few years mid-May onward . This year though all the other forecasts are as bad . One evening last week in the hope of finding relief from the heat I looked 10 days out on ECMWF 850 anomalies .. only to find a red Arctic surrounded by a complete circle of blue . It looked like a heap of Strawberries on a delft plate ..
  Such has been the movement of ice this winter and spring that most ice over a year old has already left the Arctic and the forecasts ensure that movement will continue . It really does seem that Fram , Nare's and similar export is as important as any other aspect of the melt season .
 
  Looking back through Worldview I consider the state of ice in the basin to be worse today than on 20th June 2016 or 2012 .. b.c.
 
 
 
Title: Re: The 2019 melting season
Post by: Neven on May 20, 2019, 08:39:04 PM
Vavilov glacier

Let's stay on topic, please.
Title: Re: The 2019 melting season
Post by: thejazzmarauder on May 20, 2019, 09:52:22 PM
on cue the high pressure and descending warm air are providing clear skies today over much of the Arctic basin . Worldview is beginning to reveal the unfolding disintergration of the ice . Things look in a much worse state now than in mid June last year . The fracture zones running from Beaufort to the pole show the true state of the vast majority of the ice in the basin .. ready for dispersal and melt .
  The open water showing in these fractures may be what others are seeing as rain or melt pond effects . The warmth expected over the next week may see open water around the pole even before melt season proper has begun .
 I was hoping that GFS was running away with their heat forecast as they did over the last few years mid-May onward . This year though all the other forecasts are as bad . One evening last week in the hope of finding relief from the heat I looked 10 days out on ECMWF 850 anomalies .. only to find a red Arctic surrounded by a complete circle of blue . It looked like a heap of Strawberries on a delft plate ..
  Such has been the movement of ice this winter and spring that most ice over a year old has already left the Arctic and the forecasts ensure that movement will continue . It really does seem that Fram , Nare's and similar export is as important as any other aspect of the melt season .
 
  Looking back through Worldview I consider the state of ice in the basin to be worse today than on 20th June 2016 or 2012 .. b.c.
June 20th?
Title: Re: The 2019 melting season
Post by: uniquorn on May 20, 2019, 11:00:18 PM
edit: arctic ocean today. Slight contrast adjustment to highlight fractures. https://go.nasa.gov/2JVe10v
Title: Re: The 2019 melting season
Post by: Pavel on May 20, 2019, 11:13:50 PM
The Siberian side stays cold right now but the things should change soon. It looks like we will have the blue fast ice at the end of May and the 2017 snow pattern won't take place this year
Title: Re: The 2019 melting season
Post by: be cause on May 21, 2019, 01:46:38 AM
another 350 sq km of the Arctic's finest ? ice into Nare's Straight today . providing more fracture room . It is obvious now that this really is @ the best ice in the basin that's disappearing daily . The rest of the best is dispersing in Beaufort or heading for Fram .
 The clear disintergration of the ice everywhere it has fractured from Beaufort to Kara has probably already removed the need for a GAC this year , as this ice already is and will increasingly be at the whim of the weather ...
 If circulation were to become cyclonic the open seas off Alaska and N. Canada would provide warm waters for the reception of fragmenting ice and aid dispersal Arctic wide .
The figures , especially extent , hide what is going on at the moment ( and may continue to do so for some time ) , as the ice is 'extending' by mass fracture .   b.c.

     p.s. .. and it's a 'yes' to thejazzmarauder ! 

 
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 21, 2019, 04:41:51 AM
The warmth expected over the next week may see open water around the pole even before melt season proper has begun .

From warm and melt? Near the pole? Next week? Is this what you are suggesting? It can't be. So you have to be saying that there will be huge separation between floes and that the open water will not refreeze, ya? Seems to me like there is no contrasting vectors of drift to cause this. Any open water will have little resistance and ice will drift in and fill any large gaps.

Maybe I'm missing something and there will be a shape and direction to the floes that will cause something like what you are suggesting, but please do elaborate.

Such has been the movement of ice this winter and spring that most ice over a year old has already left the Arctic and the forecasts ensure that movement will continue . It really does seem that Fram , Nare's and similar export is as important as any other aspect of the melt season .

The really good ice (5+ meters, 5+ years-old) melted out in the last 2 years. I think what we are seeing now (particularly in Nares) is what happens when the ice in the area is only a couple years old and a couple meters thick.

Looking back through Worldview I consider the state of ice in the basin to be worse today than on 20th June 2016 or 2012 .. b.c.

This year is the worst for this date with 2016 being the only other year close. Luckily June and July weather matter most...but the set up is really terrible and may not even require abnormal weather for a record. However, I would guess that if weather is mundane, 2019 minimum will be between 2012 and 2016.
Title: Re: The 2019 melting season
Post by: Neven on May 21, 2019, 11:00:05 AM
Back to the Beaufort. I would say that there's hardly a difference with 2016. Maybe there's a bit more snow on the coast now, but then again, Amundsen Bay is already completely free of ice. In the comparison below, I've added June 12th 2016, ie three weeks from today:
Title: Re: The 2019 melting season
Post by: slow wing on May 21, 2019, 11:08:00 AM
Apologies for commenting on the above off-topic discussion, Neven, but imho important to clear up the false information on this thread that melt-out of the Vavilov ice cap would allegedly add 1 foot to sea level = 305 mm.

The volume of the Vavilov ice cap is 570 km^3
Ref. Massive destabilization of an Arctic ice cap, Michael J. Willis et al, Earth and Planetary Science Letters Volume 502, 15 November 2018, Pages 146-155
[This appears to be the study causing all the alarm.]


Total area of the Earth's Oceans is 360 million km^2
The density of ice is ~0.92 of the density of water.

So sea level rise if the Vavilov ice cap melted out entirely = 0.92 x 5.7e2 km^3 / 3.6e8 km^2
= 1.5e-6 km
= 1.5 mm.

So the sea level rise would be 1.5 mm.
Title: Re: The 2019 melting season
Post by: Neven on May 21, 2019, 12:01:54 PM
Apologies for commenting on the above off-topic discussion, Neven

No problem, I'll just post something on-topic again.  ;D

Finally - finally! - the ECMWF 6-day forecast is looking much better for the sea ice. We'll have 2-3 more days of winds pulling away the ice from the coasts in the Beaufort and Chukchi, but then lower pressure takes over. Maybe the action will then shift to the Siberian side, but that's not entirely clear as of yet (to my eyes at least):
Title: Re: The 2019 melting season
Post by: be cause on May 21, 2019, 12:09:29 PM
In reply to GSY , I expect the fractures to remain open .. it looks like open water yesterday @ 89'N 130E .maybe only 2 km X 200m .. the largest bead on the string .. but if it is open water it is only a few miles from the pole and temps look like preventing significant refreeze in the coming days . I am not forecasting an ice free pole .. 'just' open water in the area .
Really it is the level of pre-conditioning in advance of melt season proper that has my concern . b.c.

ps.  thankfully the more extreme forecasts are fading ..
Title: Re: The 2019 melting season
Post by: Neven on May 21, 2019, 12:13:28 PM
At the same time, lots of heat coming in, 2.8 °C above average by next week, which equates to 0 °C for much of the Arctic:
Title: Re: The 2019 melting season
Post by: subgeometer on May 21, 2019, 12:28:05 PM
The currebt ECWMF forecast on windy TV also shows insane warmth through the forecast, for example large areas above 0 at 950mb all thru at 950mb every day, and the surface temp near or above 0 by end of forecast



Title: Re: The 2019 melting season
Post by: Rich on May 21, 2019, 01:05:22 PM
The currebt ECWMF forecast on windy TV also shows insane warmth through the forecast, for example large areas above 0 at 950mb all thru at 950mb every day, and the surface temp near or above 0 by end of forecast

Can you translate "insane warmth" into a scientific term? Perhaps using old fashioned techniques like numbers and comparison with hisrorical norms?
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 21, 2019, 01:39:10 PM
it looks like open water yesterday @ 89'N 130E .maybe only 2 km X 200m

MODIS doesn't often give a clear view of the pole, but it did yesterday:

https://go.nasa.gov/2EmOpGm

With luck we'll get another glimpse in a few days?
Title: Re: The 2019 melting season
Post by: RikW on May 21, 2019, 02:49:37 PM
I was just checking beaufort sea on NASA Worldview, based on the may 20th images I'd say it's in really bad condition. Checking the 20th of May in the last 10 years, 2016 was the worst and 2019 isn't much better.

Worldview link: https://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Terra_CorrectedReflectance_TrueColor,Graticule,Coastlines&t=2019-05-20-T00%3A00%3A00Z&z=3&v=-2786514.8516380293,-1030998.8688008119,1145645.1483619707,1035433.1311991881&ab=off&as=2017-04-15&ae=2017-05-07&av=3&al=true
Title: Re: The 2019 melting season
Post by: Trebuchet on May 21, 2019, 03:10:54 PM
At the same time, lots of heat coming in, 2.8 °C above average by next week, which equates to 0 °C for much of the Arctic:

 Warm low pressure intrusions are not necessarily a bad thing as they bring clouds. This time of year cold and sunny is far worse than warm and cloudy. We dodged a bullet in 2016 due to this and I'm hoping for a repeat.
Title: Re: The 2019 melting season
Post by: oren on May 21, 2019, 03:24:58 PM
Back to the Beaufort. I would say that there's hardly a difference with 2016. Maybe there's a bit more snow on the coast now, but then again, Amundsen Bay is already completely free of ice. In the comparison below, I've added June 12th 2016, ie three weeks from today:
The Beaufort looks really bad. But Wipneus' UH area chart still shows there is a bit more ice than in 2016, although the gap has shrunk considerably.
Title: Re: The 2019 melting season
Post by: bbr2314 on May 21, 2019, 03:28:31 PM
Back to the Beaufort. I would say that there's hardly a difference with 2016. Maybe there's a bit more snow on the coast now, but then again, Amundsen Bay is already completely free of ice. In the comparison below, I've added June 12th 2016, ie three weeks from today:
The Beaufort looks really bad. But Wipneus' UH area chart still shows there is a bit more ice than in 2016, although the gap has shrunk considerably.
It's interesting comparing the PAC front with previous years, as recent "bad years", despite Bering problems, saw a major stall in momentum in May and June. This year, it appears the front is marching forth with almost nothing getting in its way...
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 21, 2019, 03:54:26 PM
The Beaufort looks really bad. But Wipneus' UH area chart still shows there is a bit more ice than in 2016, although the gap has shrunk considerably.

Taking the Pacific side as a whole 2019 currently leads the pack. Compare and contrast with the Atlantic side:
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 21, 2019, 04:06:32 PM
Taking the Pacific side as a whole 2019 currently leads the pack. Compare and contrast with the Atlantic side:

Which is exactly what one would expect once the arctic lost all of its older ice and thus its rigidity. The ice is more free than ever to drift into the atlantic. I think this will get more severe in the coming years until there isn't enough ice left to make its southern journey.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 21, 2019, 04:43:07 PM
Part of what makes the Beaufort Sea look so bad ("matching" 2016) is the 'missing' ice in Amundsen Gulf (part of the Canadian [Arctic] Archipelago), as Neven pointed out.  An enlargement of the Wipneus chart (https://sites.google.com/site/arcticseaicegraphs/regional) (below) suggests about 20,000 km2 less CAA ice this year than in 2016 in mid-May (about the reverse of the current Beaufort difference).
Title: Re: The 2019 melting season
Post by: Killian on May 21, 2019, 05:52:38 PM
Taking the Pacific side as a whole 2019 currently leads the pack. Compare and contrast with the Atlantic side:

Is it compare and contrast or is it cause and effect? Seems to me the winds are mostly sending ice toward Fram, Svalbard, et al. In the last 7 years it has seemed pretty common for the sea ice to stay north of the archipelago and we had low export out the Fram Strait, particularly in summer. Hasn't it been true of the big melt years, '07, '10, '12 that the winds pushed a lot of ice out the Fram with the dipole, etc.?

All that action on the Pacific side is the cause of the ice pushing against Svalbard and out the Fram. Since 2012, things mostly calmed down to very good ice retention conditions overall during summers. May be the same here, but if not, and the ice flow out the Fram continues the whole season, 2019 and 2012 may end up playing patty fingers, much to the priest's and mother's dismay.

Yes, I'm ready for the historical error corrections given it's likely I made some.

 ;D

Cheers
Title: Re: The 2019 melting season
Post by: gerontocrat on May 21, 2019, 06:16:43 PM
Back to the Beaufort. I would say that there's hardly a difference with 2016. Maybe there's a bit more snow on the coast now, but then again, Amundsen Bay is already completely free of ice. In the comparison below, I've added June 12th 2016, ie three weeks from today:
The Beaufort looks really bad. But Wipneus' UH area chart still shows there is a bit more ice than in 2016, although the gap has shrunk considerably.
NSIDC area sea ice graph looking a bit different.
2018 much lower than 2018, but still about 100 km2 more than 2016
Title: Re: The 2019 melting season
Post by: echoughton on May 21, 2019, 06:55:21 PM
The warmth expected over the next week may see open water around the pole even before melt season proper has begun .

From warm and melt? Near the pole? Next week? Is this what you are suggesting? It can't be. So you have to be saying that there will be huge separation between floes and that the open water will not refreeze, ya? Seems to me like there is no contrasting vectors of drift to cause this. Any open water will have little resistance and ice will drift in and fill any large gaps.

Maybe I'm missing something and there will be a shape and direction to the floes that will cause something like what you are suggesting, but please do elaborate.

Such has been the movement of ice this winter and spring that most ice over a year old has already left the Arctic and the forecasts ensure that movement will continue . It really does seem that Fram , Nare's and similar export is as important as any other aspect of the melt season .

The really good ice (5+ meters, 5+ years-old) melted out in the last 2 years. I think what we are seeing now (particularly in Nares) is what happens when the ice in the area is only a couple years old and a couple meters thick.

Looking back through Worldview I consider the state of ice in the basin to be worse today than on 20th June 2016 or 2012 .. b.c.

This year is the worst for this date with 2016 being the only other year close. Luckily June and July weather matter most...but the set up is really terrible and may not even require abnormal weather for a record. However, I would guess that if weather is mundane, 2019 minimum will be between 2012 and 2016.


How does "the really good ice" melt out in the past two years, when we ended the last two years with close to 4 million square K of ice left from the previous year(s)???
Title: Re: The 2019 melting season
Post by: Sterks on May 21, 2019, 07:04:09 PM
At the same time, lots of heat coming in, 2.8 °C above average by next week, which equates to 0 °C for much of the Arctic:
The way I see it it is going to be nuclear until Saturday, then things get more normal.
I would be surprised if the ice stays this white in Beaufort and CAA. Should be blueish esp in the channels and near the coast, or there's a lot of snow-on-ice to melt in these regions
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 21, 2019, 07:52:03 PM
Quote
How does "the really good ice" melt out in the past two years, when we ended the last two years with close to 4 million square K of ice left from the previous year(s)[?]
Much by simple export to the melting fields.  Otherwise, when 'good ice' gets fractured to smithereens, then almost anywhere (except for the central-and-towards-the-CCA part of the Arctic Basin [so far]) can become a melting field.  (Of course, melting occurs 'everywhere', just not necessarily enough to melt 'really good ice'.)
Title: Re: The 2019 melting season
Post by: be cause on May 21, 2019, 08:37:10 PM
Hi Echoughton ..
most has left the basin on the Fram express ably abetted by the Nares strait ..
 
If you look on the Nares thread , Uniquorn posted April 30th (post 1629) .. an ascat gif of the season till then . You can watch as the older ice consolidates and moves . I can only guestimate area that heads out of the basin but it is a lot . That loss has continued for the last 3 weeks .
 
I hope Uniquorn will consider updating us on this thread as it is the best visual demonstration of what is actually happening I have seen . If he does it will probably become the most downloaded post on the site .. :) b.c.
Title: Re: The 2019 melting season
Post by: magnamentis on May 21, 2019, 10:18:14 PM
2018 much lower than 2018, but still about 100 km2 more than 2016

not that it matters for most of us but there apparently is a typo in the year, twice 2018 ?

sorry if i'm the one who doesn't see things right ;)
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 21, 2019, 10:35:20 PM
How does "the really good ice" melt out in the past two years, when we ended the last two years with close to 4 million square K of ice left from the previous year(s)???

Here's a slightly out of date NASA video that illustrates the process:

http://youtu.be/AsRflXO9mCs

It's taken a lot more than two years! However here too is an up to date graph from the NSIDC (https://nsidc.org/arcticseaicenews/2019/05/rapid-ice-loss-in-early-april-leads-to-new-record-low/) that reveals virtually no remaining 5+ year old ice:

Title: Re: The 2019 melting season
Post by: Jim Hunt on May 21, 2019, 10:40:49 PM
Seems to me the winds are mostly sending ice toward Fram, Svalbard, et al.

Seems that way to me also. See uniquorn's recent ASCAT video (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg200069.html#msg200069) for some evidence of that.
Title: Re: The 2019 melting season
Post by: uniquorn on May 21, 2019, 10:48:24 PM
Following on from yesterdays relatively cloud free image of the arctic ocean (or estuary) here is a comparison of yesterday's ascat with the same image.(may20)
As the temperatures warm up and ice surface melts and refreezes ascat will struggle to differentiate ice provenance as can already be seen in the chukchi and north of NSI in this image. Weather interference also becomes more dominant.
Title: Re: The 2019 melting season
Post by: uniquorn on May 22, 2019, 12:03:33 AM
The short term forecast for the Mackenzie watershed is crazy.<snippage>
It's bad today, but still a few days behind 2016. Not so many large floes in the Beaufort though.
Worldview terra modis, mackenzie may15-21.
2016 here: https://go.nasa.gov/2Er9zDk
Title: Re: The 2019 melting season
Post by: oren on May 22, 2019, 12:14:15 AM
The snow on the ground around the delta took a severe beating during these 6 days.
Title: Re: The 2019 melting season
Post by: uniquorn on May 22, 2019, 12:28:54 AM
agreed oren. In a few days time it could be much worse than 2016.
Title: Re: The 2019 melting season
Post by: magnamentis on May 22, 2019, 01:24:21 AM
looking at neven's images upthread once can see that on first glance 2016 looks worse but in fact once putting into account the condition of the adjacent ice area that is many times larger than the blue ocean part there is about only half of the ice now in total in that part compared to 2016, hence the difference in numbers is not that easy to measure but very close to being on par between the two years.

IMO that means somehow that there is more ice in contact with water than in 2016. one could say that the edge-line of the ice is way longer (analog to the term coast-line for land that is bordering to water)

resume:

- beaufort is similarly bad

- pacific side is worse

- atlantic side will melt out anyway, hence even though it's in better shape than other years,
the overall situation is not boding well.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 22, 2019, 03:02:47 AM
How does "the really good ice" melt out in the past two years, when we ended the last two years with close to 4 million square K of ice left from the previous year(s)???

It is quite simple: The good stuff went thru fram, nares, the caa "garlic press", or into the beaufort gyre and it melted.

It's taken a lot more than two years! However here too is an up to date graph

Yes it has taken more than 2 years, but up until 2 years ago there were regions that had continuous old thick ice. The last two summers saw that come to an end and now there really is none left except, in theory, some bits and pieces scattered about.

What is significant about this development is that the region of good ice had been acting as a plug and an anchor. Nares stayed moderately plugged up and the ice north of the caa and greenland stayed anchored to the coasts. Now a storm could easily blow the ice north any time from june to september.

Thanks for the graph. The 4+ ice is now asymptotically/effectively zero.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 22, 2019, 03:09:28 AM
It will be much much worse in a few days. Today the heat arrived and it was 14C ( vs 4C yesterday). Tomorrow is forecast to be 18C, the next day 20C, the next day 21C. The GIFs will be awesome  ;)

Keep in mind that this is not a warm and cloudy intrusion. It is very sunny and should remain so until the 25th when things get back to reasonable temps.
Title: Re: The 2019 melting season
Post by: Killian on May 22, 2019, 03:55:53 AM
- pacific side is worse

- atlantic side will melt out anyway, hence even though it's in better shape than other years,
the overall situation is not boding well.

I made this point with Jim Hunt, but it's worth repeating, it seems, because I'm not sure if it's not being recognized that all that ice along Svalbard, et al., and in the East Greenland Sea is not a case of the ice there "being in better shape," it is the direct result of the eastward flow of the ice pack from the Pacific side to the Atlantic due to currents and eastward winds/occasional dipoles.

That is, years ago it was normal for the ice to be stacked up against Svalbard, but that has mostly changed as the ice pack has thinned and lost area and extent, particularly since 2012.

You all do a great job of tracking all this stuff, so much so I rarely comment anymore because you've blown past my knowledge level. However, this is an important dynamic that I think a little more clarity in language will help make clear for those less versed or for newbies so they understand the ice dynamics. That ice is there because we currently (this spring) are experiencing nearly perfect conditions for ice loss. We have:

* early loss on the Pacific side, creating space.
* overall long-term weakness (loss of old, thick ice) making the pack more mobile
* overall lower extent, area and volume, all making the pack more mobile
* high temps generally

**** generally eastward winds pushing the ice toward Fram.****

Again, the ice conditions around Svalbard are not better, they're a really bad sign; they indicate high ice loss via Fram, etc., and are the direct result of movement elsewhere, not growth or recovery of ice - which is what a word like "better" would mean to me.

Not meaning to be overly pedantic, just think it's a distinction worth making.
Title: Re: The 2019 melting season
Post by: A-Team on May 22, 2019, 03:59:51 AM
Quote
be cause: can only guestimate area that heads out of the basin but it is a lot
Right. Wind-driven ice motion has been extraordinary this freeze/melt season. By translocating thicker, older ice into zones that will melt out later in the summer, or exporting ice altogether out of the basin via the Fram, Nares and Svalbard-FJL chain plus blocking Kara Sea ice on the import side, wind-driven ice motion may challenge conventional bottom and top melt this year as the leading ice volume loss mechanism.

The first image below shows  on mid-basin Atlantic-side feature drift (boundary between old and new ice) over the the last 195 days using twenty-day contours.

A similar area of ice ahead of the front has been (or will be if wind patterns keeps up) irreversibly displaced out of the basin. This area can be measured, not adjusting for compression or extension, by lifting geo-referenced Ascat images onto Google Earth Pro for its ellipsoidal (WGS84) area and length calculations (2nd image shows the 7.109 million sq km polygon of relevant Arctic Ocean.

Wx predictions are the proverbial drunk looking for her car keys under the street lamp because the light is better there -- winds thousands of meters above the ice are easier to predict than the 0m winds, yet only the latter actually move the ice pack (by coupling to pressure ridges and floe edges rather than flat pan).

You can see this on any given day by comparing ice motion vectors observed by OSISAF/NSIDC to winds GFS or ECMWF are showing, before or after reanalysis (3rd image). Surface currents are negligible (or as oceanographer R Woodward notes, induced by ice keels) outside the intake funnels of the Nares and Fram and inconsistent Bering Strait flows to/from the Chukchi. Note the ice pack has a certain amount of mechanical rigidity, leading to cohesive motion despite a heterogeneous stress field.

The Arctic Ocean is seriously 'under-instrumented', meaning models have never had sufficient calibration or feedback guidance. On the rare instances an instrumented ship has been out there in May (eg N-ICE spring 2015), measurements departed markedly even from nearby land stations like Ny-Ålesund. However nobody ever fixed a weather model or reanalysis based on a basin instrument account.

Help is in sight (with a 2-3 year delay?): this Sept, AWI's Polarstern will drift for a full year on a thick Siberian-side floe (lol !) to collect "direct in-situ observations of the climate processes that couple the atmosphere, ocean, sea ice, bio-geochemistry and ecosystem ... to enhance understanding of the regional and global consequences of Arctic climate change and sea-ice loss and improve weather and climate predictions. https://www.mosaic-expedition.org

This won't be meagre point weather and ice properties because they are going out to a 50 km swath radius on both sides of the drift track. The 4th image shows a hypothetic drift trajectory. They'd have been home early this year whereas in 2017/18 the ship would hardly have moved in the hoped-for direction:

233 days of anti-transpolar drift 2017-2018.mp4
https://forum.arctic-sea-ice.net/index.php/topic,2278.msg155398.html#msg155398

The Oden made a remarkable observation of open water at the north pole on 25 Aug 18, photographing a walrus there, messing with a research sled. Ask yourself how much open water there had to be regionally for a walrus to swim to the NP on that date and when it last ate: the water is 4,087 m deep whereas the deepest walrus dive ever recorded is 500m.

This and a few little things like ice thickness went seriously under-reported (except by Jim Hunt and twitter). This has really got to change -- scientists chewing on their cud for years (buffing their journal articles) while leaving everyone else in the dark.

I had an identical experience trying to get even the most mundane CTD casts from the Polarstern when by great good fortune they were able to reach the Weddell Sea during that unprecedented reversal of the Fram in Feb 18 attributed to a sudden stratospheric warming. A cr*ppy article by another research group ensued who also couldn't get the data. Where is the public benefit in  hoarding?
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 22, 2019, 04:05:53 AM
ALL HAIL A-TEAM. LONG MAY HE REIGN.
Title: Re: The 2019 melting season
Post by: be cause on May 22, 2019, 04:46:18 AM
no wonder I couldn't sleep tonight .. Welcome back A-team ! :)  b.c.
Title: Re: The 2019 melting season
Post by: wdmn on May 22, 2019, 04:56:50 AM
Just wanted to share tealight/nico sun's ice concentration map from the 20th of May. Not sure how it compares to previous years, but to my novice eyes, given what many of you have been saying about ice moving from the Pacific to Atlantic side due to winds/currents, it does not look good at all.
Title: Re: The 2019 melting season
Post by: Aluminium on May 22, 2019, 05:01:26 AM
May 17-21.
Title: Re: The 2019 melting season
Post by: Rich on May 22, 2019, 06:09:27 AM
Thank for the image Aluminum. Looks like quite a crack emanating from the Siberian Islands toward the coast.

The amount of ice connecting the main pack of ice to the coast on the Pacific side is shrinking. A piece near Barrow that doesn't look like it will last long and where the Chuchki meets Russia.

Does the whole thing speed up much when the coastal connections are lost?
Title: Re: The 2019 melting season
Post by: epiphyte on May 22, 2019, 06:48:41 AM
May 17-21.

That's beyond scary. Is there anywhere important that isn't fading fast?
Title: Re: The 2019 melting season
Post by: oren on May 22, 2019, 08:32:00 AM
May 17-21.
Seems the disturbing movement away from the Beaufort, into the Fram/Barents is continuing. Hopefully Neven's forecast is right and this sustained movement will subside soon.

In other news, aptly named A-Team is back, with A-class material. A happy day on the ASIF.
Title: Re: The 2019 melting season
Post by: Ice Shieldz on May 22, 2019, 08:38:14 AM
Holy mother of some else's god, is A-Team going to be posting again!!!???

Aluminum thanks for your ice concentration gifs and abiding by a consistent naming convention for your files - that made it easier for me to compile several of them into an April 19th to May 19th animation. Please see oren's post below for the actual animation.

EDIT: For those interested, I uploaded the animation as a 698px wide mp4 file to a remote web server, and img embedded the file link directly in this message, but that only worked on Safari browser - should have checked other browsers. Anyways, to have an mp4 file be playable on screen, instead of requiring a click to open in a separate window, ftp/upload the file to a server, if you have access to one, then follow oren's guidance below and embed the file link with url instead of img, which seems to work cross platform in multiple browsers, although the video appears smaller than it actually is. On a final note, the mp4 is compressed for streaming.
Title: Re: The 2019 melting season
Post by: oren on May 22, 2019, 08:50:38 AM
For those like me who are interested, here is Ice Shieldz' link as a URL, hopefully this works.
https://5thworld.net/ASIF_Uploads/Aluminium_Sea_Ice_Concentration_2019_April19-May19_a.mp4 (https://5thworld.net/ASIF_Uploads/Aluminium_Sea_Ice_Concentration_2019_April19-May19_a.mp4)
Title: Re: The 2019 melting season
Post by: jdallen on May 22, 2019, 09:21:48 AM
I've been browsing worldview and here's the thing that strikes me thinking about the six odd years that I have been watching the ice on this forum; no one region (well maybe the Bering) is especially bad or "worst" that we have seen.  It is hard to quantify, but what stands out is no region is in "good" shape.  Metrics across the arctic for area, thickness and extent all seem to be in the bottom three worst of our record, with few exceptions. Visually, anecdotally across the basin the ice quality looks awful, and I'm waiting to watch melt ponds break across the basin like a nasty rash.

The metaphor I come back to is a punch-drunk boxer swaying helplessly after climbing up off the mat.

Instead of looking for 2+ sigma events that could mangle the ice, we are hoping for 2+ sigma events to prevent a repeat of 2012.  That, by itself is quite a change. One good shot, and it's over, but worse, it no longer needs to be a haymaker to put us into 2012 territory.
Title: Re: The 2019 melting season
Post by: BenB on May 22, 2019, 10:40:10 AM
I agree that up to now nowhere has stood out as exceptionally bad, but Beaufort is beginning to look pretty awful:

(https://wvs.earthdata.nasa.gov/api/v1/snapshot?REQUEST=GetSnapshot&TIME=2019-05-21&BBOX=-1940480,108544,-1719552,274176&CRS=EPSG:3413&LAYERS=MODIS_Aqua_CorrectedReflectance_Bands721,Coastlines&FORMAT=image/jpeg&WIDTH=863&HEIGHT=647&ts=1558514205722)

The open water is probably mainly related to ice drift, but there is clear surface melting and melt ponding going on as well. The forecast is for high (above zero) temperatures for the coming week, so it's only likely to get worse.
Title: Re: The 2019 melting season
Post by: Neven on May 22, 2019, 11:34:45 AM
ECMWF weather forecast for coming 6 days: Two more days of ice pulling away from the Beaufort Sea coast, and then slow things down, but Day 6 (bottom right) may be indicating a return to bad synoptics for the ice, with high pressure taking over the Central Arctic again. Day 7 to 10 are more emphatic, but they're too unreliable, so I generally don't post those.
Title: Re: The 2019 melting season
Post by: JayW on May 22, 2019, 12:11:57 PM
132 hour loop, Beaufort sea.  Band I1 (red/visible) May 16, 12Z - May 22, 0Z.
http://rammb-slider.cira.colostate.edu/?sat=jpss&z=3&im=60&ts=1&st=20190519111138&et=20190522041913&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=0&slider=-1&hide_controls=1&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=northern_hemisphere&p%5B0%5D=band_i01&x=16784&y=20096
Title: Re: The 2019 melting season
Post by: johnm33 on May 22, 2019, 12:27:14 PM
Worth looking at this to compare
(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortictn_nowcast_anim30d.gif)
Title: Re: The 2019 melting season
Post by: oren on May 22, 2019, 12:55:38 PM
ECMWF weather forecast for coming 6 days: Two more days of ice pulling away from the Beaufort Sea coast, and then slow things down, but Day 6 (bottom right) may be indicating a return to bad synoptics for the ice, with high pressure taking over the Central Arctic again. Day 7 to 10 are more emphatic, but they're too unreliable, so I generally don't post those.
I normally leave synoptics to my betters, but isn't the day 3-4 setup highly supportive of ice export into the Barents/Fram?
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 22, 2019, 12:56:41 PM
Wind-driven ice motion has been extraordinary this freeze/melt season.

Welcome back, and it has indeed!

Quote
The Oden made a remarkable observation of open water at the north pole on 25 Aug 18, photographing a walrus there, messing with a research sled.

See below.

Quote
This and a few little things like ice thickness went seriously under-reported

Melt pond season is (almost?) upon us, so these CryoSat-2 sea ice thickness maps relate to the end of April. A comparison of 2019 with 2012. Not exactly apples versus oranges, but the 2019 version merges CS2 with SMOS around the edges.

P.S. Endeavouring to compare apples with apples I've discovered that the Alfred Wegener Institute makes NRT CS2 and merged CS2/SMOS data available at: ftp://ftpsrv2.awi.de/sea_ice/product/ (ftp://ftpsrv2.awi.de/sea_ice/product/)

See the last image below.
Title: Re: The 2019 melting season
Post by: be cause on May 22, 2019, 01:09:15 PM
I see the walrus brought supplies . Sadly the reassuring mountainous ice behind him has long since been exported via Fram . I would like to see a photo same time and place this sunner .. b.c.
Title: Re: The 2019 melting season
Post by: Pavel on May 22, 2019, 01:15:12 PM
The weather conditions are perfect for the MYI export and we'll have mostly FYI remaining at the North Pole. I'm also concerned about the possible early surface melting at the North Pole so we may have many holes by the end of season
Title: Re: The 2019 melting season
Post by: Sterks on May 22, 2019, 02:51:26 PM
ECMWF weather forecast for coming 6 days: Two more days of ice pulling away from the Beaufort Sea coast, and then slow things down, but Day 6 (bottom right) may be indicating a return to bad synoptics for the ice, with high pressure taking over the Central Arctic again. Day 7 to 10 are more emphatic, but they're too unreliable, so I generally don't post those.
I normally leave synoptics to my betters, but isn't the day 3-4 setup highly supportive of ice export into the Barents/Fram?
Yes, and with high pressures parked over Greenland I would say day 1-6, but true that 1-4 seem most supportive
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 22, 2019, 02:53:10 PM
Worth looking at this to compare
My IE shows this as a little box with an X.  The link is
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortictn_nowcast_anim30d.gif
"Security" is bad, but I go to this Navy site with peace of mind.
Title: Re: The 2019 melting season
Post by: Rich on May 22, 2019, 03:47:11 PM
I'm just a new layperson / lurker here so not sure what this means.....but it looks like there could be a continuous line of blue water from the Beaufort Sea  meandering all the way around the coast to the Laptev Sea within a week or two.

I think the last piece to detach will be in the Chuchki.

Whatever sticky resistance is currently being offered via the coastal connection will be severed. The pressure toward the Atlantic seems to be growing.

Take it with a grain. I'm just a newbie.
Title: Re: The 2019 melting season
Post by: Phil. on May 22, 2019, 05:07:26 PM
Wind-driven ice motion has been extraordinary this freeze/melt season.

Welcome back, and it has indeed!

Quote
The Oden made a remarkable observation of open water at the north pole on 25 Aug 18, photographing a walrus there, messing with a research sled.

Not the only interested local on that trip;

(https://portalen.polar.se/wp-content/uploads/2018/08/arctic-ocean-2018-lars-lehnert-isbjorn-01_LL-0295-1.jpg)
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 22, 2019, 05:32:32 PM
Not the only interested local on that trip

Speaking of which, a couple of reminders of Oden's visit to the North Pole in 2016:
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on May 22, 2019, 07:23:52 PM

it looks like we started getting sediment in the water in front of the MacKenize a few days ago. The 16th seemed to be pretty clear, the 21st cloudy.
Title: Re: The 2019 melting season
Post by: be cause on May 22, 2019, 08:02:31 PM
algal bloom ? .. b.c.

or .. you are right Rox .. the brown patches growing out from the delta across the ice suggests flow and other years esp. 2016 show this is exactly on cue ..
Title: Re: The 2019 melting season
Post by: gerontocrat on May 22, 2019, 08:21:10 PM
algal bloom ? .. b.c.
I go for sediment - the flood comes in a rush bringing vast quantities of silt etc that flows and spreads as it hits the ocean.
Title: Re: The 2019 melting season
Post by: be cause on May 22, 2019, 08:31:36 PM
Cheers Gerontocrat .. I had just corrected my post .. although the green tinge may well be algae too .. b.c.
Title: Re: The 2019 melting season
Post by: RoxTheGeologist on May 22, 2019, 10:17:41 PM
algal bloom ? .. b.c.
I go for sediment - the flood comes in a rush bringing vast quantities of silt etc that flows and spreads as it hits the ocean.

Looks like it started on the 17th, day 126, slap bang in the middle of the flow data.
Title: Re: The 2019 melting season
Post by: Michael Hauber on May 23, 2019, 12:05:05 AM
Here is a recent photo of sediment.

(https://s.w-x.co/wu/ms-river-mar-21-2019_0.jpg)

From Cat 6 (https://www.wunderground.com/cat6/Americas-Achilles-Heel-Mississippi-Rivers-Old-River-Control-Structure) blog.

Of course not all sediment will look exactly the same.
Title: Re: The 2019 melting season
Post by: be cause on May 23, 2019, 02:03:47 AM
this winter and spring if you only followed dmi80 you would expect us to be in recovery mode this year . The cold has been hugging Greenland and the old ice as it passed to it's graveyard in the N. Atlantic .

For the last 4 weeks dmi80 has tracked 2018 incredibly closely . This day last year dmi80 temps dropped below the mean , where they essentially stayed for the next 3 months ...
 
If this year it is different , potentially everything will be .

I would assume a huge amount of energy would be involved in producing an air temp of 1'C above mean as opposed to 1'C below for any length of time above 80'N ?
 
And what energy no longer needs to be expended because of export of thick cold ice this season ?

How large has the energy balance shifted in the last few months and recent days toward a BOE ?
 
Does the living planet look like it may gift Greta with the most powerful symbol of the threat that awaits if we do not step back right now from consuming our own future ?  b.c.

nite nite :)
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 23, 2019, 03:09:13 AM

it looks like we started getting sediment in the water in front of the MacKenize a few days ago. The 16th seemed to be pretty clear, the 21st cloudy.

And on the 22nd, smoke (I'm pretty sure, from fires in Alberta).

The forecast has calmed a tiny bit as it has approached but the next two days are still going to be much hotter than today, and I'll be surprised if the fast ice around the delta isn't in bits and pieces by he 26th's imagery.

The fires throughout the canada are bad and likely to get much much worse. If the smokes settles on arctic ice, it is a death blow. The forecast was far out as is meaningful is terrible. Luckily it won't be windy, so the short term fire outlook is okayish, but the super heat causes dryness and the fuel in these areas is extremely abundant. The severe anomalies are currently north of the current fires, but this weather makes fires possible closer and closer to the arctic.
Title: Re: The 2019 melting season
Post by: magnamentis on May 23, 2019, 03:38:18 AM

Not meaning to be overly pedantic, just think it's a distinction worth making.

it's not overly pedantic, on the contrary, it's obvious and self-evident and this is the probable reason why it's not talked about that much. what i'm saying is that the echo to your repeated mention of this is not because we don't believe you, but because i for one think, yeah, sure, has been clear from day one and nobody ever said otherwise.

so we fully agree and sometimes it's worth to remember that one fact does often not exclude another. mentioning one reason does not mean it's the only reason etc. etc.

hence all good you're 100% correct with your assessment.
Title: Re: The 2019 melting season
Post by: Rich on May 23, 2019, 04:42:06 AM
Random observation.

After watching the gif that Aluminum posted in #953 above, I was very interested in the major crack developing across the East Siberian Sea over the last few days

I checked a map of ocean depth in the area and this crack is developing across arguably the shallowest shelf in the Arctic. From what I can tell, less than 10m depth.

It occurs to me that another part of the story of 2019 is warm subsurface water getting pushed against the coasts and weakening the perimeter defenses.
Title: Re: The 2019 melting season
Post by: Neven on May 23, 2019, 09:22:46 AM
Right. Wind-driven ice motion has been extraordinary this freeze/melt season. By translocating thicker, older ice into zones that will melt out later in the summer, or exporting ice altogether out of the basin via the Fram, Nares and Svalbard-FJL chain plus blocking Kara Sea ice on the import side, wind-driven ice motion may challenge conventional bottom and top melt this year as the leading ice volume loss mechanism.

Welcome back, A-Team.  :)

This animation of weekly ice age distribution maps from Feb 5th to May 6th shows how much of the MYI has been pushed towards the Atlantic exit, while some of the oldest ice is sucked off by Nares, and the 'Arm' in the Beaufort doesn't look all that strong this year:
Title: Re: The 2019 melting season
Post by: oren on May 23, 2019, 11:08:40 AM
This animation of weekly ice age distribution maps from Feb 5th to May 6th shows how much of the MYI has been pushed towards the Atlantic exit, while some of the oldest ice is sucked off by Nares, and the 'Arm' in the Beaufort doesn't look all that strong this year:
The animation looks very similar to the Ascat animation, which lends credibility to the ice age distribution near the Atlantic exits. With continued export expected for at least several more days, this will only get worse. And the red bits are actually shown as disappearing into the Nares, despite the coarse resolution. A very bad setup into the peak of the melting season. Dodging required - again.
Title: Re: The 2019 melting season
Post by: Neven on May 23, 2019, 11:59:21 AM
For those interested in what happened in the Beaufort, back in 2016 (so as to compare to this year's siutation), I wrote about it extensively on the ASIB. Here's a blog post (https://neven1.typepad.com/blog/2016/05/beaufort-final-update.html) from May 21st, with links to previous blog posts in the first paragraph.

One thing I wondered about back then, and do again now:

Quote
The other thing is that there is actually not that much ice left between the large polynya (expanse of open water) in the Beaufort Sea and the smaller one in the Chukchi Sea:

(https://neven1.typepad.com/.a/6a0133f03a1e37970b01b7c86055f6970b-800wi)

Once this ice is gone, there will be open water all along the American coast of the Arctic Ocean. My guess is this could happen within two weeks or maybe even faster, which would be extremely early, given that the earliest time this has happened in the past decade (and probably much, much beyond that), was between July 1st and 7th in both 2009 and 2011.

My guess turned out to be wrong. It also took until the first week of July for open water to take over all along the Alaskan-Canadian coast.

But how about this year? Here's a comparison:

(https://lh3.googleusercontent.com/DJEOgapTuogXVZLhsLRDJxCu2HKUCNVcNTMgfGFJofn7sEo950o69-pu91uuSDcwphvPAfbgUMIGSSm91_-Em1gkluCBZeOCwcqEfSfUBuIitAS6xBRkiUwXDjFjf3LdR4xY4QwFwoz0HsGYhlgIPFHgYnexidKJALfHKIEt3XXbSpgnvcWZm4QBdi9vDIngAyFso4fN6YMtnVxqQe29vfHY_9zsJgatphLvFQquAdm9urd4td3qaVNqCGdayruXC-Xmm2qIxiNrAPnXBdol9tMXKi3A9UHa9-CmTEsb48b2XJPBgRR1Y4AOu6G7S5-vOap2Rp6e09ooFQoXaeNIZZ8g2BsdLWpl4NOJoSiDMaJSFp2M_jbn9JAZ98T2qg-OAlcYctt4TYuPDCOHdcfRXO1VYwfVl0E-IGJ87D0-YNqeHNTF6NC6nLcceoq3JzqZ2Z2dxR2KxCmBDFQE0_Ue_XetjdoRhub32apMby-KfFD5EcnDBMAptoZBMq0UBpTznTv_zEVS9RS_mMVZ-El_KcT8miDQLMDi_-NFNteE8hSiYux_mdPzoQ8CnUzPILG6CM3vhgMAfap0KdyfN4FW83SPZScfzT3pB8XwJy9dXs5Zj5V7gWeZU1guk0oUvaW0V6YbPtW538ztkFS7PfokOSp44NXEVw4qdGzZkPrxaNjbdt1uo1L0JgYFhGYmZewJaTf1UMRTEBoSqHBkDbhozCQk=w500-h410-no)

The maps look very similar, so much so that one would be tempted to think there is something causing the ice to stay glued to the coast, all the way up to Utqiaġvik. But there's no "Chukchi polynya" now, with open water all the way to the Pacific and far into the Chukchi, meaning there is less ice to be blown back towards the coast, should the winds turn.

And the winds are another similarity. Both the weather forecast back then and the one this year show a change in the set-up that caused the early Beaufort opening, around the same time. However, this year there may be a return to that set-up next week.

So, wondering if there will be open water all along the Alaskan-Canadian coast before July this year...
Title: Re: The 2019 melting season
Post by: Neven on May 23, 2019, 12:20:20 PM
Mind you, 2016 came really, really close to opening in the first week of June, but then the fast ice off Barrow broke and disintegrated, blocking the way until ice floes from the Chukchi moved in for further blockage.

We'll see where 2019 is at 10 days from now.
Title: Re: The 2019 melting season
Post by: echoughton on May 23, 2019, 12:34:43 PM
Terrific stuff, Neven!! Learning is so much fun
Title: Re: The 2019 melting season
Post by: wallen on May 23, 2019, 12:56:44 PM
The fast ice at Barrow doesn't appear as resilent as in 2016.
Title: Re: The 2019 melting season
Post by: gerontocrat on May 23, 2019, 01:47:42 PM
There is a bit of a cold blob in the centre of the far north of North America.
It looks like this will warm up by middle to late next week.

It gives me a little more confidence in the prediction that belongs to me that the North-West Passage will open this year.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 23, 2019, 02:48:37 PM
This animation of weekly ice age distribution maps from Feb 5th to May 6th

Excellent! The NSIDC have released their promised "quick look" ice age product, including a NetCDF version. Here's an alternative take on the Atlantic side of the Arctic, comparing 2019 with 2012.

Should anyone else be interested 2019 data is available via: https://nsidc.org/data/nsidc-0749/versions/1

Older data is at: https://nsidc.org/data/nsidc-0611
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 23, 2019, 02:50:57 PM
But how about this year? Here's a comparison:

I can't see your image Neven. All I get is:
Title: Re: The 2019 melting season
Post by: Rich on May 23, 2019, 03:07:57 PM
To Neven's question about whether there will be open water on the Alaska / Canada coast by July.

I think there may be an open water path all the way around the coast from CAA to the Laptev. There may be a stubborn remnant or two hanging on the coast, but nothing contiguous with the CAB.

I'm curious how far east the open coast in Canada will go. There's already open water along the Western 1/3 of the CAA and wonder if the open water will continue spreading toward Ellesmere.

I'm new here, but I did go back and peruse the 2016 thread and think 2019 is looking more vulnerable from the standpoint of coastal ice connection to the main pack.

My hunch is that we're seeing the effect of Atlantification.

Title: Re: The 2019 melting season
Post by: Neven on May 23, 2019, 03:08:30 PM
But how about this year? Here's a comparison:

I can't see your image Neven. All I get is:

Sorry about that, Jim. Somehow, I always manage to screw up linking to Google Photo images.

Here it is:
Title: Re: The 2019 melting season
Post by: magnamentis on May 23, 2019, 06:15:18 PM
The fast ice at Barrow doesn't appear as resilent as in 2016.

it will be gone very soon, one morning we wake up and it will be no more, i predict within days, rather than weeks.

my guess: 3-6 days from now but that's a guess based on the images of the webcam, one can't see the exact thickness.
Title: Re: The 2019 melting season
Post by: pearscot on May 23, 2019, 06:22:52 PM
Although I don't post much, I do read here an awful lot and take a vast majority of what is said/posted to heart. I'm kinda in shock at how the arctic is looking...while my predictions have been inverse to the reality of emulating a 2012 event, the overall continuity of the ice looks far from 'healthy.' I don't know how the rest of the year will unfold, but I've been following the currents very closely the last two years and I still believe that the arctic's biggest foe may perhaps be the ever increasing atlantification.

Nonetheless, I will never claim to be in expert on this complex system, however seeing as the el nino is quickly fading into a more neutral pattern while at the same time the main development region of the Atlantic region continues to warm - the crux of this being more of a potential for heat engines (hurricanes/post tropical systems) to more readily/easily make their way into the northern latitudes in conjunction with an extremely strong gulf stream current. I will sit back and await the sad devolution of the pristine abyss.

(https://www.ospo.noaa.gov/data/sst/anomaly/2019/anomnight.5.20.2019.gif)
Title: Re: The 2019 melting season
Post by: Rich on May 23, 2019, 07:12:49 PM
The fast ice at Barrow doesn't appear as resilent as in 2016.

it will be gone very soon, one morning we wake up and it will be no more, i predict within days, rather than weeks.

my guess: 3-6 days from now but that's a guess based on the images of the webcam, one can't see the exact thickness.

I might be inclined the agree with your you. Given that there is something stubborn about that patch, I'm going to guess 1-2 weeks.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 23, 2019, 07:40:33 PM
With people making guesses on this thread, I opened a new poll on the topic (https://forum.arctic-sea-ice.net/index.php/topic,2704.msg200709/topicseen.html#msg200709).
Quote
Quote

my guess: 3-6 days from now but that's a guess based on the images of the webcam, one can't see the exact thickness.
I might be inclined the agree with your you. Given that there is something stubborn about that patch, I'm going to guess 1-2 weeks.
Title: Re: The 2019 melting season
Post by: El Cid on May 23, 2019, 07:50:24 PM
Looking at the latest forecasts (GFS 1200UTC,ECMWF 00UTC) there seems to be no end in sight for sunny skies above the Pacific side. After day 5, both show consistent high pressure there. And looking at the picture above, posted by Neven, 2019 definitely looks much worse than 2016. If the sun keeps doing its job, we will lose the Beaufort and the Chukchi very soon...
Title: Re: The 2019 melting season
Post by: Pragma on May 23, 2019, 07:56:38 PM

This animation of weekly ice age distribution maps from Feb 5th to May 6th shows how much of the MYI has been pushed towards the Atlantic exit, ...

Hello all,

I regularly learn from this excellent site, but rarely post. I can't always follow developments in detail, but studying the above animation, I was shocked by the widespread mobility of the ice, so early in the season.

It stands to reason that previously, older and thicker ice would tend to be more cohesive and resistant to winds and currents but then I realized I have no real reference for how things have changed. The whole arctic ocean seems to be one big slushie now.

I am guessing that the ice was never truly monolithic. I am aware of the huge drop in multiyear, low salinity ice but I can't relate that to stability. Can someone help me get a feel for average ice behaviour ten or twenty years ago regarding movement?

I'm happy to study it myself, if someone can recommend appropriate archive links, but I suspect the applicable tools and products weren't around then.

Things seem bad, but I guess I'm really asking "How bad, how fast?". Is this disintegration relatively recent and/or sudden?

Thanks
Title: Re: The 2019 melting season
Post by: magnamentis on May 23, 2019, 08:00:19 PM

I might be inclined the agree with your you. Given that there is something stubborn about that patch, I'm going to guess 1-2 weeks.

stubborn LOL, exactly my thought recently, starting 2-3 days ago, after the open water is there
for weeks and almost all snow an ice on and inland is gone.

let's see but it's very brownish and dark on that surface all depends on thickness/compaction a few hundred meters out.
Title: Re: The 2019 melting season
Post by: be cause on May 23, 2019, 08:10:48 PM
Hi Pragma .. Worldview goes back to 2000 in easily accessible archives .. only this year have I got internet sufficient to take advantage but haven't explored that far back yet .
  re the ice of Barrow .. in 2016 @ now Beaufort cooled for several weeks .. enough for ice melt to cease for weeks on the Pacific side .. causing the stall that can be seen in extent and area that year . This year there is no hint of similar happening . b.c.
Title: Re: The 2019 melting season
Post by: Sarat on May 23, 2019, 09:01:32 PM
Pragma here is a good visual last decade has been significantly different: https://www.facebook.com/YearsOfLiving/videos/1142262632527460/
Title: Re: The 2019 melting season
Post by: ArcticMelt2 on May 23, 2019, 10:00:06 PM
This animation of weekly ice age distribution maps from Feb 5th to May 6th shows how much of the MYI has been pushed towards the Atlantic exit, while some of the oldest ice is sucked off by Nares, and the 'Arm' in the Beaufort doesn't look all that strong this year:

The rapid destruction of the multi-year ice is very bad. This may suggest that the last ice in the Arctic will melt near the North pole rather than the Northern shores of Canada and Greenland.

This will be a disaster for polar bears. They will not be able to escape in Canada and Greenland, and all will drown near the North pole.
Title: Re: The 2019 melting season
Post by: Neven on May 23, 2019, 10:06:57 PM
This will be a disaster for polar bears. They will not be able to escape in Canada and Greenland, and all will drown near the North pole.

 :D

That's not going to happen. But there is no way that Arctic sea ice loss will be good for polar bears.
Title: Re: The 2019 melting season
Post by: ArcticMelt2 on May 23, 2019, 10:10:57 PM
This will be a disaster for polar bears. They will not be able to escape in Canada and Greenland, and all will drown near the North pole.

 :D

That's not going to happen. But there is no way that Arctic sea ice loss will be good for polar bears.

Why do you think this is unlikely? You wrote last year how the Northern shores of Greenland were cleared of ice at the end of August. It is obvious that there is a high probability that polar bears will fall into the ice trap in the Central Arctic and die.
Title: Re: The 2019 melting season
Post by: Pragma on May 23, 2019, 10:19:41 PM
b.c. - That's an excellent resource. It's going to take me a while to learn how to drive it, but the info is all there. Thank you.

Sarat - I think one could watch that video 50 times and not get all the information from it. It tells so much of the history of the Arctic ice in one compact video.

From all of this I see that the ice is extremely fluid and Fram export has been a regular feature "forever". I don't see anything particularly dramatic but more just a slow, progressive decline. Any drama is just the stochastic nature of the weather and cyclical influences such as the PDO and AMOC laid over top.

That said, whereas the GAC of 2012 produced drama and much speculation, it was simply an anomaly, albeit a big one. Soon, a much smaller "alignment of the stars" will produce the same results.

A cursory glance at ASIE or ASIC is useful, but can be misleading. The last thin layer will vanish like morning frost in sunlight and some will proclaim a "collapse" has occurred.

BTW, the last week of the Keeling Curve CO2 concentration put us solidly above 415 ppm for the peak of this cycle. This is well over a 3 ppm jump, whereas previous annual increases were in the range of 2.5 ppm, or less.

The inevitability of it all saddens me.

Correction: CO2 Concentration is now 415 ppm, not 215 ppm.
Title: Re: The 2019 melting season
Post by: FrostKing70 on May 23, 2019, 10:30:57 PM
Polar bears can swim a loooonnnnnggggg way.....

https://news.mongabay.com/2012/05/just-how-far-can-a-polar-bear-swim/

"Polar bears (Ursus maritimus) are capable of swimming incredible distances, according to a new study published in Zoology, which recorded polar bears regularly swimming over 30 miles (48 kilometers) and, in one case, as far as 220 miles (354 kilometers). The researchers believe the ability of polar bears to tackle such long-distance swims may help them survive as seasonal sea ice vanishes due to climate change."
Title: Re: The 2019 melting season
Post by: ArcticMelt2 on May 23, 2019, 10:41:18 PM
Polar bears can swim a loooonnnnnggggg way.....

https://news.mongabay.com/2012/05/just-how-far-can-a-polar-bear-swim/

"Polar bears (Ursus maritimus) are capable of swimming incredible distances, according to a new study published in Zoology, which recorded polar bears regularly swimming over 30 miles (48 kilometers) and, in one case, as far as 220 miles (354 kilometers). The researchers believe the ability of polar bears to tackle such long-distance swims may help them survive as seasonal sea ice vanishes due to climate change."

This is a rare case for very strong bears. In addition, the nearest land to the North pole is much further - about 700 km.

https://en.wikipedia.org/wiki/Kaffeklubben_Island
Quote
Kaffeklubben Island or Coffee Club Island (Danish: Kaffeklubben Ø; Greenlandic: Inuit Qeqertaat) is a small island lying off the northern tip of Greenland. It contains the northernmost point of land on Earth. Kaffeklubben Island is at 83°39′45″N 30°36′50″W and is 713.5 kilometres (443.3 mi) from the geographic North Pole.

The coming massacre will be one more comparable to the destruction of mammoths, bison and wandering pigeons.

https://en.wikipedia.org/wiki/Extinct_in_the_wild
Title: Re: The 2019 melting season
Post by: Neven on May 23, 2019, 10:51:00 PM
The coming massacre will be one more comparable to the destruction of mammoths, bison and wandering pigeons.

https://en.wikipedia.org/wiki/Extinct_in_the_wild

Yes, but not in one year, and not in the way you're describing.
Title: Re: The 2019 melting season
Post by: uniquorn on May 23, 2019, 10:55:09 PM
Please take the polar bear discussion to the appropriate thread, maybe this one https://forum.arctic-sea-ice.net/index.php/topic,2348.0.html

Despite the drift, the atlantic side north of FJL/Svalbard is also not looking good.
edit: worldview aquaterra modis, may21-23 https://go.nasa.gov/2M7P0lt
Title: Re: The 2019 melting season
Post by: magnamentis on May 23, 2019, 11:56:25 PM
This will be a disaster for polar bears. They will not be able to escape in Canada and Greenland, and all will drown near the North pole.

 :D

That's not going to happen. But there is no way that Arctic sea ice loss will be good for polar bears.

Why do you think this is unlikely? You wrote last year how the Northern shores of Greenland were cleared of ice at the end of August. It is obvious that there is a high probability that polar bears will fall into the ice trap in the Central Arctic and die.

google how far and how long polar bears can and do swim, even when they don't necessarily have to, you'll be surprised and know why this won't happen the way you describe.

neven's take on this is as spot on as it can get. bad for the bears but they won't drown in numbers.
Title: Re: The 2019 melting season
Post by: Greenbelt on May 24, 2019, 01:14:49 AM
This river delta in the general area of Prudhoe Bay on the north slope of Alaska appears to have started spilling water into the ice of the last couple days.
(https://wvs.earthdata.nasa.gov/api/v1/snapshot?REQUEST=GetSnapshot&TIME=2019-05-22&BBOX=-2124800,523776,-1982720,626432&CRS=EPSG:3413&LAYERS=MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&FORMAT=image/jpeg&WIDTH=555&HEIGHT=401&ts=1558653096251)
Title: Re: The 2019 melting season
Post by: Michael Hauber on May 24, 2019, 01:32:41 AM
For those interested in what happened in the Beaufort, back in 2016 (so as to compare to this year's siutation), I wrote about it extensively on the ASIB. Here's a blog post (https://neven1.typepad.com/blog/2016/05/beaufort-final-update.html) from May 21st, with links to previous blog posts in the first paragraph.

The maps look very similar, so much so that one would be tempted to think there is something causing the ice to stay glued to the coast, all the way up to Utqiaġvik. But there's no "Chukchi polynya" now, with open water all the way to the Pacific and far into the Chukchi, meaning there is less ice to be blown back towards the coast, should the winds turn.

And the winds are another similarity. Both the weather forecast back then and the one this year show a change in the set-up that caused the early Beaufort opening, around the same time. However, this year there may be a return to that set-up next week.

So, wondering if there will be open water all along the Alaskan-Canadian coast before July this year...

My guess there are two factors behind this 'ice bridge'.  First there seems to be more fast ice on the coast - presumably the sea bed is shallow and/or perhaps currents favour colder water below the ice.  Second I suspect the beaufort gyre and shape of the coast line combine.  Ice I think tends to move away from the coast towards Chukchi and towards CAA, but towards the coast near this ice bridge.  As soon as temps warm enough that ice can't form these two areas become ice free as ice moves away from the coast, but the ice bridge area needs temps to warm enough that substantial ice in the Beaufort at large is melted and there is no longer enough ice to move towards the coast.

(https://i.imgur.com/3qRadCY.gif)

(using paint so hard to get a nice curve to better illustrate the ice flow)
Title: Re: The 2019 melting season
Post by: ArcticMelt2 on May 24, 2019, 03:44:13 AM
google how far and how long polar bears can and do swim, even when they don't necessarily have to, you'll be surprised and know why this won't happen the way you describe.

neven's take on this is as spot on as it can get. bad for the bears but they won't drown in numbers.

Answered in the neighbors topic
https://forum.arctic-sea-ice.net/index.php/topic,2348.msg200803.html#new
Title: Re: The 2019 melting season
Post by: subgeometer on May 24, 2019, 03:55:27 AM
The ECMWF(as well as GFS is showing building heat in northern Eurasia, with the Lena catchment in for a warm blast, all lowland snow south of the Laptev is projected to be gone by the end of the forecast period. (And the forecast ends with temps above 20C on the Barents Sea coast as yet another trough ushers mid-latitude heat toward the pole, eek)
Title: Re: The 2019 melting season
Post by: subgeometer on May 24, 2019, 05:25:55 AM
The Laptev bite has re-opened over the past 3 days, about 30-40km wide in this Worldview image(23may), and the ice front being pushed away is mush that froze a couple of weeks ago, and will soon melt  in time for peak insolation. Warm southerlies are forecast starting in a day or so, at first directed at the intervening snow, and progressively warming as it melts out- I've attached the Windy/ECMWF forecast for tuesday

You can follow the line separating fast ice and mobile pack all the way east along the ESS coast. The ice in the western ESS looks  better, but from the central ESS coast to Wrangel Island and beyond the ice is just ghastly, a loose pack/slurry of widely separated small  floes interspersed with mush(thelargest are about 25km across, and roundish rather than angular in shape, which puts a question mark over their strength and integrity)

Edit: removed a misplaced bracket and duplicated particle.
Title: Re: The 2019 melting season
Post by: Alphabet Hotel on May 24, 2019, 05:48:23 AM
That area extending northward from the New Siberian Islands looks bad on the AMSR2 image. I scaled that part up and tried to sharpen it a bit. The whole area looks like it has a fractal pattern of cracks.
Title: Re: The 2019 melting season
Post by: Ice Shieldz on May 24, 2019, 06:18:06 AM
ASCAT arctic sea ice comparison 2012, 2016, 2018 and 2019 Jan1–May22
click zoom icon to expand
https://5thworld.net/ASCAT-ArcticSeaIce_2012_16_18_19_Jan-May22.mp4 (https://5thworld.net/ASCAT-ArcticSeaIce_2012_16_18_19_Jan-May22.mp4)
Title: Re: The 2019 melting season
Post by: Killian on May 24, 2019, 06:51:51 AM
neven's take on this is as spot on as it can get. bad for the bears but they won't drown in numbers.

Well, no, they won't "all" drown, but *more* are and even more *will* as there is less and less ice. A hungry, skinny bear can't swim as far as a well-fed bear. And, "in numbers" is relative. As a species crashes further and further, smaller and smaller numbers come to equal "in numbers." (E.g., there are an estimated 80k koalas in the wild. Seems like a lot of koalas, eh? No, They are considered functionally extinct.) And we have a lot more warming to go.


Grolar/Prozzly Bears might be the only way they survive.
Title: Re: The 2019 melting season
Post by: Aluminium on May 24, 2019, 07:14:59 AM
May 19-23.
Title: Re: The 2019 melting season
Post by: Killian on May 24, 2019, 07:54:38 AM

Not meaning to be overly pedantic, just think it's a distinction worth making.

it's not overly pedantic, on the contrary, it's obvious and self-evident and this is the probable reason why it's not talked about that much.

But, that wasn't my point.

the echo to your repeated mention

Twice? LOL...

of this is not because we don't believe you, but because i for one think, yeah, sure, has been clear from day one and nobody ever said otherwise. so we fully agree

Well, of course you do! But that also was not my point...

and sometimes it's worth to remember that one fact does often not exclude another. mentioning one reason does not mean it's the only reason etc. etc.

Also not a point I had made. But thanks for the pat on the head! ;-)

hence all good you're 100% correct with your assessment.

Generally, yes. But also not my point.

My point:

When I first arrived at the SIB many years ago, the language was pretty dense, the references to places, locations, effects, resources a mess for me. I had no problem understanding the ice dynamics in and of themselves because, well, I'm neither uneducated nor of low intelligence. In fact, I posted somewhat regularly and didn't feel out of place doing so. However, the jargon, the info, the labels... tough. (Now? Ten years and little participation since 2012/13 or so has left me well behind. I won't be posting much bc you all can do better than I.)

So, if, as you say, the posters here know it all, so need not point out the obvious, then how does such a statement as this slip through?

Quote
"being in better shape,"

It's a misleading description of conditions. Thus, was the poster being a bit too colloquial/relaxed, or had the poster not realized the dynamics at play? As you should understand from my post, I assumed the latter. But, I also explained the dynamics. Why? For you? For Neven? For Hunt?

Of course not. For:
Quote
this is an important dynamic that I think a little more clarity in language will help make clear for those less versed or for newbies so they understand the ice dynamics.

Because I remember what it was like in the beginning for me and, as a teacher, I try to notice when I am stating things that are assumptions for me, but not for my audience.

And that was why I posted, not to inform you of ice dynamics, but to remind long-time posters that what is background to you is likely mysterious to new users.

Better shape? Not really. Bad news. Newbies might have missed this.

Cheers
Title: Re: The 2019 melting season
Post by: Rich on May 24, 2019, 07:54:55 AM
I love the gifs Aluminum. Thank you.

The last couple of days added haven't been especially noteworthy. The blue water around the Siberian Islands / Laptev have expanded a fair amount.
Title: Re: The 2019 melting season
Post by: oren on May 24, 2019, 07:55:36 AM
May 19-23.
The Beaufort has crashed and now equals terrible 2016. The Laptev opened again after the previous gap refroze. The Greenland Sea is replenished with newly exported ice.
AMSR2 area graphs show it all clearly.
Title: Re: The 2019 melting season
Post by: sark on May 24, 2019, 09:33:51 AM
When has the 500mb anomaly chart EVER looked so splotchy for so long?  All I see is retrograde motion, pro-rotating cells of cold forced off the ice.  This hasn't yet been spinning up storms in the Arctic.  Should we expect that next?
Title: Re: The 2019 melting season
Post by: wallen on May 24, 2019, 10:32:33 AM
There is a bit of a cold blob in the centre of the far north of North America.
It looks like this will warm up by middle to late next week.

It gives me a little more confidence in the prediction that belongs to me that the North-West Passage will open this year.

NW passage aside, Given the extensive cracking that has occurred across the CAA and above Greenland already this season. What possible chance of that passage opening later on. If I recall there was an open passage between Fram strait and Naire Strait, late last year.
Title: Re: The 2019 melting season
Post by: be cause on May 24, 2019, 10:46:15 AM
I hope it is a comic farcast .. gfs ends at 4'c on the north shores of Greenland and Ellesmere Island .. b.c.
Title: Re: The 2019 melting season
Post by: Neven on May 24, 2019, 11:14:39 AM
Given the current weather and temperature forecasts, my gut feeling says we're in for some big drops in the coming week. Whatever improvement there was in the forecast, it's now reverting back to the set-up we've seen these past weeks, where the ice will continue to be transported westwards along the Alaskan coast, and then into the CAB. The open water in Laptev will probably start to expand again, and some more action is to be expected in Kara. Export towards the Atlantic is slow, but steady, and the Atlantic hasn't even gone full Cookie Monster yet. Hudson is about to start falling off a cliff.

This stuff is now moving into June...
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 24, 2019, 11:55:51 AM
It gives me a little more confidence in the prediction that belongs to me that the North-West Passage will open this year.

See the 2019 section of the Northwest Passage thread: https://forum.arctic-sea-ice.net/index.php/topic,762.msg192845.html#msg192845

Quote
If I recall there was an open passage between Fram Strait and Nares Strait, late last year.

Not far off:

Title: Re: The 2019 melting season
Post by: Jim Hunt on May 24, 2019, 12:06:25 PM
Better shape? Not really. Bad news. Newbies might have missed this.

Take a close look at Ice Shieldz' ASCAT video (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg200814.html#msg200814) above, and this explanatory still (https://forum.arctic-sea-ice.net/index.php/topic,2591.900.html) from A-Team:

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2591.0;attach=120754;image)

In case it's not readily apparent, "new ice" is dark, "old ice" is light.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 24, 2019, 12:22:47 PM
Melt ponds are making an appearance on the Siberian side:

https://go.nasa.gov/2Jy4GfG
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 24, 2019, 12:31:12 PM
Meanwhile over on the Mackenzie Delta: https://go.nasa.gov/2M7eVcU

Try clicking through to Worldview and taking a look at the same areas in 2016 and 2012
Title: Re: The 2019 melting season
Post by: be cause on May 24, 2019, 12:35:51 PM
Hi Jim .. are you sure re the melt ponds ? I doubt this ice is thick enough . I suggest the ice has melted below the surface snow and it is sea water coming through to the surface we are seeing . b.c.
 Update .. poof .. and it was gone ! Today's Worldview shows what was blue ice yesterday is blue ocean today . Everything is changing ..

ps .. ref post 1030 ..
Title: Re: The 2019 melting season
Post by: echoughton on May 24, 2019, 12:38:04 PM
How do we know how old certain sections of ice are? Jim's color map comparison of 2019 vs 2012 has all kinds of colors sprinkled throughout, telling us exactly when small sections....sq- k it looks like...were created. Seems impossibly odd to be able to identify this giant floating chunk as 3 years old, another iceberg is 2 years old...etc. Do they go around tagging hundreds of floating ice masses up there?
Title: Re: The 2019 melting season
Post by: JayW on May 24, 2019, 12:38:27 PM
7 day Melt pond fraction forecast from ESRL, Physical science division.

https://www.esrl.noaa.gov/psd/forecasts/seaice/
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 24, 2019, 01:12:31 PM
Hi Jim .. are you sure re the melt ponds ?

I'm sure about the Mackenzie Delta fast ice. I'm willing to debate the Siberian slush. I'll go and see if Landsat/Sentinel have snapped the area recently.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 24, 2019, 01:18:31 PM
How do we know how old certain sections of ice are?

Here's the link again: https://nsidc.org/data/nsidc-0611

Quote
The method used to estimate sea ice age involves Lagrangian tracking of sea ice from week-to-week using gridded ice motion vectors (Maslanik et al. 2011; Tschudi et al. 2019). Starting in late 1978, ice age can be estimated by treating each grid cell that contains ice as a discrete, independent Lagrangian parcel and tracking the parcels at weekly time steps as they are advected by the weekly ice motions. The process can be viewed as a set of stacked planes overlying the grid used, with each plane corresponding to an age category. Parcels move around on their respective planes, independent of parcels of other age categories, which in turn lie in their own planes. To produce maps of ice age, the set of parcels for each weekly time increment is rasterized by assigning parcels to the 12.5 km x 12.5 km grid cell within which each parcel's position lies. In cases where parcels of different ages fall within a single grid cell, the age of the grid cell is assigned to the oldest parcel (Maslanik et al. 2011; Tschudi et al. 2019). Physically, this approach assumes that younger ice deforms more easily than older ice, and as such older ice will cover a greater fraction of the area within the grid cell. For example, if two parcels, one that represents first-year ice and one that represents third-year ice, both fall within the domain of a single grid cell, then the age of that cell will be assigned as third-year ice.

If the ice concentration of a grid cell remains at or above 15 percent throughout the melt season, then that parcel is assumed to have survived the summer minimum sea ice extent (typically reached in September), and the parcel's age is incremented by one year. The age of the ice is categorized as first-year ice (0-1 years old), second-year ice (1-2 years old), and so forth based on how many summer melt seasons the ice parcel survives (Tschudi et al. 2010). Note that grid cells with less than 15 percent sea ice concentration are treated as open water, even though the cells could still contain some ice.
Title: Re: The 2019 melting season
Post by: pearscot on May 24, 2019, 06:50:33 PM
Maybe I'm just overreacting....but I'm just in shock at how the ice is looking right now. There's far more I need to discern and research, but that ice is just not looking 'good' at all. Sorry I don't have a more analytical post, but hmmm....
Title: Re: The 2019 melting season
Post by: Pragma on May 24, 2019, 10:03:50 PM
My point:

When I first arrived at the SIB many years ago, the language was pretty dense, the references to places, locations, effects, resources a mess for me.

...

Because I remember what it was like in the beginning for me and, as a teacher, I try to notice when I am stating things that are assumptions for me, but not for my audience.

And that was why I posted, not to inform you of ice dynamics, but to remind long-time posters that what is background to you is likely mysterious to new users.


Ref. Reply # 1021

I think this is an excellent point that could be missed by people deep into it. After a hiatus, I have to refresh everything in spite of what I learned. (where is that damned "garlic press"?). ;-)

The very issue of ice to the south of Svalbard  and Novaya Zemlya tripped me up until I realized the "shadows", indicating ice floe direction. It's all about ice dynamics and looking at various details with respect to overall context. The context is essential.

As I mentioned before, ASIE is of limited value without ASIC and if strong winds affect the edges, ASIE can change drastically in a day, with little or no actual change in the situation except for albedo.

This is why the good people here dig deeper for a better understanding, but the basics are needed to understand the nuances and implications. I'm slowly getting there.

I have probably pointed out several "obvious" things just in this post that are far from obvious to an occasional reader.

Cheers
Title: Re: The 2019 melting season
Post by: Sarat on May 25, 2019, 12:48:28 AM
Maybe I'm just overreacting....but I'm just in shock at how the ice is looking right now. There's far more I need to discern and research, but that ice is just not looking 'good' at all. Sorry I don't have a more analytical post, but hmmm....

Yeah, I agree that animation from IceShieldz above looked just like 2012 except with much lower Alaskan ice extent for the date:
(https://pbs.twimg.com/media/D7QsXFjV4AEhzX7.jpg:large)
Source: Rick Thoman (@AlaskaWx) Twitter
Title: Re: The 2019 melting season
Post by: Ice Shieldz on May 25, 2019, 10:19:58 AM
Sarat - it's hard to gauge thickness from ASCAT. Someone like Jim probably has a more trained eye that can better interpret the shades of grey, which are not well-delineated for the eye to discern. Clouds can also get in the way, and there seems to be a slightly different grey value mapping with the data back in 2012?

For this following gif, i'm inclined to put more credence in the Navy's thickness model - as they have a high stake in knowing how thick the ice is to hide submarines and more easily pop through the thinner ice. But i'm sure there are others here that have a better sense of model accuracy. However, my understanding from A-Team and others is that there's a dearth of real-world measurements to validate the accuracy of these models.  – May require click to animate
Title: Re: The 2019 melting season
Post by: El Cid on May 25, 2019, 10:32:04 AM
Ok, so as Frivolousz21 is not around, I have to replace him:

The latest ECMWF forecast is absolutely mindboggling (see T+6 chart). I don't think I have ever seen anything like this in my life - you have to go back to the Holocene Optimum to find anything resembling it. The Pacific side and the Pole is getting bombarded 24/7 as long as the eye can see. The Beaufort is going to evaporate like it's never been there. The Chukchi is already extremely weak, and this going to hit it like a torpedo and it's going to sink like the Titanic.
Full sunshine during peak insolation is the recipe for TOTAL COLLAPSE. This year we are going to see the North Pole wide open! Mark my words, THIS IS EPIC.

 :) :) :)
Title: Re: The 2019 melting season
Post by: subgeometer on May 25, 2019, 10:33:02 AM
The current GFS run on climate reanalyser show absolutely insane temperatures extending across northern Eurasia from about 4 days out, and then get worse and worse for the remainder off the run, ending up with solid 20C anomalies along the coast. Something to watch as it comes closer.

If these kind of forecasts bear out and continue there will be absolutely stupendous fires, possibly dwarfing anything seen before. There are already large areas of smoke visible in Canada west of Great Slave Lake

I've attached there GFS temp anomaly 105 hrs out
Title: Re: The 2019 melting season
Post by: Neven on May 25, 2019, 10:38:14 AM
Ok, so as Frivolousz21 is not around, I have to replace him:

I'll give you a 5/10 for the effort, but friv cannot be replaced so easily.  ;D

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
Title: Re: The 2019 melting season
Post by: Pavel on May 25, 2019, 10:47:55 AM
I don't expect a collapse at this point. There is positive snow anomalies in Siberia and melting goes slower than 2012
Title: Re: The 2019 melting season
Post by: Neven on May 25, 2019, 11:09:26 AM
The light blue on that map is exactly where all the heat will be in the coming week:
Title: Re: The 2019 melting season
Post by: Killian on May 25, 2019, 11:20:10 AM
My point...

as a teacher, I try to notice when I am stating things that are assumptions for me, but not for my audience.

And that was why I posted, not to inform you of ice dynamics, but to remind long-time posters that what is background to you is likely mysterious to new users.

Ref. Reply # 1021

I think this is an excellent point that could be missed by people deep into it. After a hiatus, I have to refresh everything in spite of what I learned.

...with respect to overall context. The context is essential.

..This is why the good people here dig deeper for a better understanding, but the basics are needed to understand the nuances and implications...

I have probably pointed out several "obvious" things just in this post that are far from obvious to an occasional reader.

I don't want to make a "thing" of this, as the casual reader, aka the student, has a responsibility to self-educate, also, but I appreciate someone else sees the point. The world is, literally, falling apart. This is not the biggest thing on anyone's agenda, but a little awareness and patience and care with phrasing can be a real help to others. We all need to "get there" at some point, or none of us will, so...

Thanks for commenting.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 25, 2019, 11:23:33 AM
Ok, so as Frivolousz21 is not around, I have to replace him:

Thanks for delivering the superlatives so well.

It has to be said though, Frivolousz21 is not yet beaten in how to paint a dystopian picture.
Title: Re: The 2019 melting season
Post by: meddoc on May 25, 2019, 12:54:48 PM
arctic.io Arctic Explorer has been off for a week now.
No Wonder, more & more People must be checking out the Reality- as has the number of new members started to grow.
Title: Re: The 2019 melting season
Post by: Lord M Vader on May 25, 2019, 01:24:55 PM
While the current forecast indeed looks really bad with a high amount of sunshine and temps climbing above zero, there might be a chance that we get a high pressure similar to what happened back in 2014. If so, the damage should be reduced.
Title: Re: The 2019 melting season
Post by: Clenchie on May 25, 2019, 01:27:02 PM
arctic.io Arctic Explorer has been off for a week now.
No Wonder, more & more People must be checking out the Reality- as has the number of new members started to grow.

I was wondering what had happened to arctic explorer.

All I get is the following message:

This site can’t be reached www.arctic.io’s server IP address could not be found.
Try running Windows Network Diagnostics.
DNS_PROBE_FINISHED_NXDOMAIN

Have switched instead to Worldview on https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines

Apologies if off topic.
Title: Re: The 2019 melting season
Post by: be cause on May 25, 2019, 01:30:12 PM
I noticed I was looking at post 1042 on page 42 at 10 42 am .. and I always say if surrounded by 42's I am in the right place .. b.c.

 p.s.  more important perhaps is it is another good Worldview day over the Arctic . The amount of open water in the cracks toward the pole is ever more unusual . I assume extent ignores them .. is area taking them into account ?
also of interest .. the 850 anomalies show very warm air above 80'N but yesterday the surface temps were just edging into negative anomaly ..

 pps ... just noticed I've 420 posts and 42 likes ..
 
Title: Re: The 2019 melting season
Post by: Sterks on May 25, 2019, 02:24:45 PM
I don't expect a collapse at this point. There is positive snow anomalies in Siberia and melting goes slower than 2012
Agree, there seems to be more snow volume as well.
However, the tendency says another story. Snow cover anomaly during May reversed a stall and is going full throttle toward a bad negative value. Also compare 2019 and 2012, day 144. I think it is catching up, is even worse in North America, and forecast says it may be bad near Siberian coasts in a week.
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 25, 2019, 02:31:56 PM
I noticed I was looking at post 1042 on page 42 at 10 42 am .. and I always say if surrounded by 42's I am in the right place .. b.c.

Happy towel day!

 8)
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 25, 2019, 04:32:59 PM
East Siberia (upper left in the picture) coast drifting off now.

Gif showing 23. vs 25.05.
Title: Re: The 2019 melting season
Post by: GoSouthYoungins on May 25, 2019, 04:36:31 PM
So my understanding is the fear for the season is:

-Pacific side heat from open water and snow anomalies.
-Central basin high pressure leading to clear skies and melt from insolation.
-Consistent export into the Atlantic ocean (and Baffin Bay)
Title: Re: The 2019 melting season
Post by: Neven on May 25, 2019, 05:31:46 PM
So my understanding is the fear for the season is:

-Pacific side heat from open water and snow anomalies.
-Central basin high pressure leading to clear skies and melt from insolation.
-Consistent export into the Atlantic ocean (and Baffin Bay)

-Couple of cyclones between sunny periods to stir the pot.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 25, 2019, 06:17:44 PM
I'm willing to debate the Siberian slush. I'll go and see if Landsat/Sentinel have snapped the area recently.

As luck would have it Landsat 8 did snap the sea ice just off Ostrov Kotelny on the 23rd. It still looks to me as though the image below reveals melt ponds on the more substantial chunks of sea ice, but I'm open to persuasion.

The VISHOP algo (https://ads.nipr.ac.jp/vishop/#/gallery/&time=2019-05-23%2000:00:00) reckoned there was surface melt in the area also.
Title: Re: The 2019 melting season
Post by: jdallen on May 25, 2019, 07:24:22 PM
Ok, so as Frivolousz21 is not around, I have to replace him:

I'll give you a 5/10 for the effort, but friv cannot be replaced so easily.  ;D

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
I'd take it a step above terrible, Neven.  They are positively terrifying.
Title: Re: The 2019 melting season
Post by: jdallen on May 25, 2019, 07:49:14 PM
Dove-tailing with the melt pond and snow cover discussion, here's a couple of screen grabs of the snow cover model from Climate Reanalyzer; the first is today, the second is for June 1st.

The takeaway is, GFS predicts snow cover over the next 6 days will be hammered, seriously.

A lot of that melt - 6-10CM worth - will be on the snowpack in the CAB.

That translates into melt ponding, some exposed, some still sub-snowcover, but absolutely suggests serious drop in albedo and preconditioning in favor of melt, under an almost arctic-wide high pressure dome.

(Edit:  A number of other things strike me.  During the entire run, there are 4 persistent circum-polar areas of low pressure - the outer Bering, SE Hudson's bay/Quebec, Northern Scandinavia/Barentz and Central/Eastern Siberia.  These low pressure regions are shoving polar air out through the Mackenzie basin south to the North American Great Plains, out through the FRAM/Svalbard region, far eastern Europe/Urals and to a lesser degree, the west side of the Bering/extreme eastern Siberia.  Heat and moisture of course flowing north between.  It looks surprisingly stable, and, with the tendency towards more stable/slower moving jet stream/rosby waves is very concerning for the rest of June.)
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 25, 2019, 08:25:16 PM
Ok, so as Frivolousz21 is not around, I have to replace him:

I'll give you a 5/10 for the effort, but friv cannot be replaced so easily.  ;D

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.
Title: Re: The 2019 melting season
Post by: be cause on May 25, 2019, 08:28:03 PM
Hi JD .. that looks unbelievable .. but somehow this year it seems like such horrorcasts are coming true ..

I notice that open water is appearing in a massive new fracture zone north of Greenland and multiple new zones of fracture are appearing everywhere as winds change .. almost all with open water visible on Worldview .
 In past years it has been argued that side melting of floes is negligible but this year I wonder .. the ice is not so thick and is already in trillions of fragments , and the sides are partially exposed to low angle sun 24/7 . Could this not be important as it bypasses the snow on the surface ? This sunlight would be absorbed by the ice and water , while the snow above prevents it radiating back to space ..
  It may not be a huge fraction of incoming solar radiation but it is a growing fraction , especially important in a sunny summer . Any thoughts ?   b.c.
Title: Re: The 2019 melting season
Post by: ArcticMelt2 on May 25, 2019, 08:29:15 PM
The situation in the Pacific sector is terrible.

(https://pbs.twimg.com/media/D7bF7oVUwAEIOiB.jpg)
Title: Re: The 2019 melting season
Post by: aperson on May 25, 2019, 08:37:34 PM
edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 25, 2019, 09:07:05 PM
Sarat - it's hard to gauge thickness from ASCAT. Someone like Jim probably has a more trained eye that can better interpret the shades of grey.

I'm not sure about that! The ASCAT "shades of grey" are dependent on the porosity and salinity of the ice, and perhaps the surface "roughness" as well:

https://www.researchgate.net/publication/299525691_Multiyear_arctic_ice_classification_using_ASCAT_and_SSMIS

That's a reasonable proxy for age, but perhaps less so for thickness? However as A-Team revealed, the boundary between the two reveals the sea ice movement towards the Atlantic over the last few months.

So does the movement of snow buoy 300234066342810 (http://iabp.apl.washington.edu/raw_plots.php?bid=300234066342810#top), which is now almost at the North Pole:

BTW, comparing the US Navy's 2012 (ACNFS) and 2019 (GOFS 3.1) model outputs is apples versus oranges:

https://forum.arctic-sea-ice.net/index.php/topic,1602.msg201189.html#msg201189
Title: Re: The 2019 melting season
Post by: Neven on May 25, 2019, 09:07:39 PM
High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.
Title: Re: The 2019 melting season
Post by: JamesW on May 25, 2019, 09:13:22 PM
Hi HelloMeteor,

If your interested in understanding shortwave radiation and longwave radiation downwelling effects on sea ice this rather comprehensive text will enlighten you on the subject at length.

https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-15-0238.1

Title: Re: The 2019 melting season
Post by: Rich on May 25, 2019, 09:23:31 PM
So my understanding is the fear for the season is:

-Pacific side heat from open water and snow anomalies.
-Central basin high pressure leading to clear skies and melt from insolation.
-Consistent export into the Atlantic ocean (and Baffin Bay)

-Couple of cyclones between sunny periods to stir the pot.

There's more. The peripheral resistance of  ice connected to the coast is fraying. We''ve had a test run of lift off from CAA earlier in the season. When those connections are lost, the main pack is going to be freer to rotate in the direction of the export.

Nares being open doesn't help. The amount of ice loss there isn't tremendous, but it's like a lubricant in a potentially sticky corner as the ice pack might try to rotate later in the season.



Title: Re: The 2019 melting season
Post by: bbr2314 on May 25, 2019, 09:42:25 PM
The upcoming / imminent pattern looks like the worst we have ever seen for the high Arctic at this time of year. The satellite pictures are already shocking. This is truly unprecedented IMO.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2019052512/ecmwf_z500aMean_nhem_6.png)

As others have noted / hinted, checking EOSDIS, most all of the PAC sector is now light blue in imagery. Unlike previous years where the advance halted before Wrangel Island, I think 2019 will see the advance continue fairly rapidly into the Chukchi and Beaufort, with most of both seas gone by 7/1.

Perhaps the biggest impact of this will not be a BOE, which is unlikely (though a record minimum? increasingly possible). But, I think it would be the accumulation of insolation in open water that has never been this open in recorded history. This is likely to result in worst-ever cyclonic activity in the High Arctic in late summer and autumn (IMO). And that is likely to translate into record-breaking disruptions for the hemispheric pattern as well, i.e., chaos in the mid-latitudes, where we all actually live.

Finally: I am shocked by the fires in Canada this year. I had been gung-ho on a worst-ever Siberian fire season, and still am. But Canada.... wow! I think this is a culmination of the worsening oscillations between hot and cold killing vegetation, as well as the warming / dissipation of permafrost. That is leading to increasing amounts of vegetation that is dead, and peat bogs that are now accessible to flames. Combined with what we are already seeing, this year is shaping up to be the worst-ever for extent and area.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fcires1.colorado.edu%2F%7Easlater%2FSEAICE%2Fthis_year_map.png&hash=c84cb3a881263b10f1b12e866b843229)

PPS: it is worth noting that Slater's model shows a record-low for 7/14, of 7.75 million KM^2. But the picture is worse than that. As of 7/14, Slater's model shows most of Hudson Bay still covered to substantial %. Same with Baffin. That ice is going to be gone by 9/1. We have an abundance of "easy" ice remaining, and even if a smidgen does survive the melt season, this will result in sustained momentum through August, and steep cliffs whenever ^^^ does melt out.
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 25, 2019, 09:43:15 PM
The open Nares is important because thick old ice passes out of the Arctic instead of piling up on the NW shores of Greenland and the NE shores of the CAA. This year, when the Fram outflow slowed the outflow through the Nares often increased. That's what happens when the pressure is relatively high over the pole and relatively low over the far north Atlantic and the subarctic seas on the Atlantic side and the Nares strait is open.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 25, 2019, 11:21:39 PM
edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?
Title: Re: The 2019 melting season
Post by: FishOutofWater on May 25, 2019, 11:42:02 PM
An engineer should understand compressional heating and drying. The ECMWF model and it's ensembles are forecasting a dome of warm air at 500mb - half of surface pressure - centered over the Arctic ocean, combined with a strong surface high. This situation produces maximum solar heating in early June and produces maximum surface heating and high temperatures.

It's a worst case forecast for sea ice.
Title: Re: The 2019 melting season
Post by: Shared Humanity on May 26, 2019, 12:01:17 AM
edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?

Hi HelloMeteor. Welcome to the site.

Actually answered the question pretty succinctly. I've been here for about 7 years and still find myself having to google terms to understand what some type here. Might be better to try this rather than ridiculing someone trying to answer your question.

Actually googled subsidence before I typed this.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 26, 2019, 12:32:38 AM
I did too. The predominant definitions are about geology.

It's just stupid to insist on using jargon when there are plenty of words 90% of people with a technical background wouldn't need to look up.
Title: Re: The 2019 melting season
Post by: Tor Bejnar on May 26, 2019, 12:34:31 AM
I'm not a weather map person, particularly, but I can put my left thumb up over the "H" on a map (helps that I'm left handed in the northern hemisphere (NH) :o) and see how the air flows (follow my other curled fingers).  With the strong high over the central Arctic and a weaker high over Greenland on the 2nd just post map (thanks FOoW), I read this to mean strong Fram export next Tuesday is forecast.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 26, 2019, 01:51:07 AM
I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 26, 2019, 02:31:16 AM
I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence


Lol, what a bunch of pretentious assholes you all are. How was I to know I had to google "high pressure" with "subsidence" to get an applicable definition of subsidence? If I should be expected to know the word, I should expect to be able to look up the definition of the word, by itself, and find it among one of the several definitions.

Jesus, you want the general public to be informed, but you make a point of trying to look WAY more intelligent than you are and attacking people who call you out on it.

If the public never "gets it", it's precisely because people acting like you.

You care more about looking smart than educating people.
Title: Re: The 2019 melting season
Post by: Pragma on May 26, 2019, 02:39:13 AM
I'm not a weather map person, particularly, ...

Neither am I but I did some googling, so to add a bit to this:

As you indicated, the high pressure systems rotate clockwise and the low pressure systems rotate anti or counter-clockwise, but I just also learned that there is a spiral aspect. The air mass in a high pressure system is "flung out" so to speak, whereas a low pressure system draws air into the centre. Makes sense, like explosion and implosion.

So, the two systems on either side of Svalbard are like two gears meshing. The HP system throws the ice from the central arctic to the LP system, which then draws it in, closer to it's demise in the North Atlantic.

Thanks FOoW, I'm with both of you that the ice is going to get very mobile soon.

Even worse is that a smaller but very similar system exists on either side of the Bering Strait. A vacuum cleaner at each side of the Arctic, how convenient!
Title: Re: The 2019 melting season
Post by: Rodius on May 26, 2019, 02:53:30 AM
I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence


Lol, what a bunch of pretentious assholes you all are. How was I to know I had to google "high pressure" with "subsidence" to get an applicable definition of subsidence? If I should be expected to know the word, I should expect to be able to look up the definition of the word, by itself, and find it among one of the several definitions.

Jesus, you want the general public to be informed, but you make a point of trying to look WAY more intelligent than you are and attacking people who call you out on it.

If the public never "gets it", it's precisely because people acting like you.

You care more about looking smart than educating people.

This seems over the top. People here have answered your question by giving links and explaining the question.
If it is confusing, it is because it is complex.
And people tend to forget that the words they use are not always in common usage or have specific meaning within the niche.

You have only been a member for a little over a week, the people here have been studying the climate for many years, are specialised in the topic and know what they are talking about. That is not being pretentious, they just forget sometimes that what they know is not common knowledge.

Google is your friend. Sometimes it takes effort to learn on your own part. Rather than lash out, thank the people for answering your question, keep asking more questions and be prepared for a learning curve.
The general public does not have time for this type of thing, which is understandable in some ways because it is complex, and many people dislike complexities because it requires effort to unfold them. It is also why the climate crisis will continue to be underestimated and will only be acted on when the brut force personally affects them.
Title: Re: The 2019 melting season
Post by: Jim Hunt on May 26, 2019, 02:55:53 AM
You care more about looking smart than educating people.

Like this you mean?

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

If your interested in understanding shortwave radiation and longwave radiation downwelling effects on sea ice this rather comprehensive text will enlighten you on the subject at length.

https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-15-0238.1

An engineer should understand compressional heating and drying. The ECMWF model and it's ensembles are forecasting a dome of warm air at 500mb - half of surface pressure - centered over the Arctic ocean, combined with a strong surface high. This situation produces maximum solar heating in early June and produces maximum surface heating and high temperatures.

It's a worst case forecast for sea ice.
Title: Re: The 2019 melting season
Post by: aperson on May 26, 2019, 02:59:00 AM
You care more about looking smart than educating people.

You indicated you were an engineer, I gave you a short response that I figured was geared toward an engineer. I will try to provide a better Simple English answer in the future to spare you from throwing a tempter tantrum.
Title: Re: The 2019 melting season
Post by: jdallen on May 26, 2019, 03:12:54 AM
I notice that open water is appearing in a massive new fracture zone north of Greenland and multiple new zones of fracture are appearing everywhere as winds change .. almost all with open water visible on Worldview .
 In past years it has been argued that side melting of floes is negligible but this year I wonder .. the ice is not so thick and is already in trillions of fragments , and the sides are partially exposed to low angle sun 24/7 . Could this not be important as it bypasses the snow on the surface ? This sunlight would be absorbed by the ice and water , while the snow above prevents it radiating back to space ..
  It may not be a huge fraction of incoming solar radiation but it is a growing fraction , especially important in a sunny summer . Any thoughts ?   b.c.
Side melt doesn't really become a factor in melt until the flow size drops considerably - 150 meter diameter and smaller.  Until then, top and bottom melt rule the day.

Insolation on side surfaces will similarly be negligible as it won't really increase the uptake of solar energy significantly.

It's all about albedo right now, which is why with snow melt (which lowers albedo), open water (which also better captures insolation) and little cloud cover (due to high pressure) is such a disturbing combination.

The interesting bit, is it might not cause immediate and steep drops in area or extent.  Volume however may start to dive, because with melt ponds and full sunlight, 4cm of ice or more could be getting stripped off each day. 

Combine that with bottom melt, and by the end of June we could end up with vast swaths of ice that has the appearance of being "OK", but is only a meter thick or less.  In this case, the real drops in area and extent will happen in July and August, as accumulated heat attacks lingering ice and just crushes it... unless we are saved again by the weather.

What also worries me is enough heat getting picked up that bottom melt continues well into late September, or potentially even early October, if SST's end up high enough.

This is going be a very interesting and possibly disturbing melt season.
Title: Re: The 2019 melting season
Post by: Greenbelt on May 26, 2019, 03:17:09 AM
Subsidence is a pretty useful precise term in meteorology. Would you also complain about a pilot using precise jargon like "elevator" or "horizontal stabilizer" or "trim" to explain an aviation concept? If you want explanation using layman's terms, feel free to ask, preferably in a different thread. This thread watches the ice and the weather etc. Mackenzie delta.
(https://wvs.earthdata.nasa.gov/api/v1/snapshot?REQUEST=GetSnapshot&TIME=2019-05-24&BBOX=-2801664,-471040,-1800192,176128&CRS=EPSG:3413&LAYERS=MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&FORMAT=image/jpeg&WIDTH=978&HEIGHT=632&ts=1558833288367)
Title: Re: The 2019 melting season
Post by: Rich on May 26, 2019, 03:29:47 AM
I'm not a weather map person, particularly, ...

Neither am I but I did some googling, so to add a bit to this:

As you indicated, the high pressure systems rotate clockwise and the low pressure systems rotate anti or counter-clockwise, but I just also learned that there is a spiral aspect. The air mass in a high pressure system is "flung out" so to speak, whereas a low pressure system draws air into the centre. Makes sense, like explosion and implosion.

So, the two systems on either side of Svalbard are like two gears meshing. The HP system throws the ice from the central arctic to the LP system, which then draws it in, closer to it's demise in the North Atlantic.

Thanks FOoW, I'm with both of you that the ice is going to get very mobile soon.

Even worse is that a smaller but very similar system exists on either side of the Bering Strait. A vacuum cleaner at each side of the Arctic, how convenient!


Also not an expert, but I don't think comparing the Bering Strait to Fram Strait is very useful. The forces driving the ice to Fram are largely based on the Earth's spin which isn't changing. The circumpolar winds rotate clockwise and the powerful East Greenland Current is pulling Arctic surface water into the Atlantic.

The weather may accentuate the movement of ice toward Fram as winds pick up and ice melts and offers less resistance to the prevailing forces, but we shouldn't expect to see a lot of ice leaving via the Bering.

If any of the more expert contributors can weigh in on how a weather system like this can change the pace of ice export, that would be appreciated.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 26, 2019, 03:31:01 AM
I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence


Lol, what a bunch of pretentious assholes you all are. How was I to know I had to google "high pressure" with "subsidence" to get an applicable definition of subsidence? If I should be expected to know the word, I should expect to be able to look up the definition of the word, by itself, and find it among one of the several definitions.

Jesus, you want the general public to be informed, but you make a point of trying to look WAY more intelligent than you are and attacking people who call you out on it.

If the public never "gets it", it's precisely because people acting like you.

You care more about looking smart than educating people.

This seems over the top. People here have answered your question by giving links and explaining the question.
If it is confusing, it is because it is complex.
And people tend to forget that the words they use are not always in common usage or have specific meaning within the niche.

You have only been a member for a little over a week, the people here have been studying the climate for many years, are specialised in the topic and know what they are talking about. That is not being pretentious, they just forget sometimes that what they know is not common knowledge.

Google is your friend. Sometimes it takes effort to learn on your own part. Rather than lash out, thank the people for answering your question, keep asking more questions and be prepared for a learning curve.
The general public does not have time for this type of thing, which is understandable in some ways because it is complex, and many people dislike complexities because it requires effort to unfold them. It is also why the climate crisis will continue to be underestimated and will only be acted on when the brut force personally affects them.

It's not confusing because it's complex. It's not even confusing. Physics, except on the quantum level, isn't confusing even when it is complex, because it's purely logical and everything fits together neatly, even when it gets complicated because physics on the macro scale fundamentally makes sense if you have a technical background. Unlike quantum physics nothing about it contradicts our experience.

Google is your friend is an obviously intentionally insulting statement.

Here's something else that is your friend:

When someone wants to learn, and asks, in so doing proving they don't know a lot about the subject, don't use jargon specific to that subject if you don't need to.

A person uses ONE WORD as if it explains something. I google it, and it's all about geology, and oh, my mistake, I should have known I had to include high pressure or meteorology as an additional keyword. Except no. There is nothing obvious about that.

Except the thing is, if I ask what's so bad about high pressure, if you apparently know so much about meteorology, you should infer quite easily that subsidence will mean even less to me than high pressure as high pressure is a term obviously more commonly used in basically every context than subsidence. That makes it quite absurd to claim the use of that word is in any way helpful to anyone that doesn't know what makes high pressure bad.

I work with mechanical engineers every day, I got a degree in aerospace engineering. We don't deal with heat transfer or HVAC often, but heat transfer has come up. The word subsidence has never come up between engineers, and we're pretty nerdy.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 26, 2019, 03:39:51 AM
High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

This on the other hand makes tons of sense. I am acquainted with meteorology and know low pressure correlates to bad (not sunny) weather, like hurricanes, the worst case example of low pressure bad weather, and high pressure correlates to bluebird or at least fair weather cumulus clouds. 

I was more interested if there was something about the pressure itself that is bad for ice. Like does high pressure mean the air is at greater density, which would mean more heat transfer from the ice to the air.
Title: Re: The 2019 melting season
Post by: Rod on May 26, 2019, 03:47:31 AM
Welcome HelloMeteor.

People were trying to help, and you got very rude.  if you have a question post it in the "stupid questions" thread. 

This thread is for a discussion of the melt season.  It turns some people off when it gets cluttered with personal attacks. 

Again, welcome to the forum.  Please try to treat people with respect.  There are some really good posters who go quiet when things get too far off topic, and things are really getting interesting now and I want to hear what they have to say.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 26, 2019, 03:51:29 AM
I only got very rude after people insulted me by saying let me google that for you or saying google is your friend.

"Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?"

That does not qualify as very rude does it? Maybe a little rude, but not very.
Title: Re: The 2019 melting season
Post by: jdallen on May 26, 2019, 03:53:08 AM
High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

This on the other hand makes tons of sense. I am acquainted with meteorology and know low pressure correlates to bad (not sunny) weather, like hurricanes, the worst case example of low pressure bad weather, and high pressure correlates to bluebird or at least fair weather cumulus clouds. 

I was more interested if there was something about the pressure itself that is bad for ice. Like does high pressure mean the air is at greater density, which would mean more heat transfer from the ice to the air.
Barometric pressure in and of itself really doesn't have any effect on the ice.

Further, heat transfer from air to ice is pretty negligible when compared to that from insolation or directly from the water - that's why melt ponds are so dangerous - they reduce albedo and put a layer of warm(relatively) water on the top surface of the ice which concentrates and transfers the heat quite efficiently.

The mechanics of the ice itself changes dramatically with temperature - ice at -20c is 4-5 times more structurally resistant to crushing and shear forces than ice at freezing ~ minus 1.8c for water in the Arctic.

But again, air pressure in and of itself really doesn't alter the melt equation.
Title: Re: The 2019 melting season
Post by: HelloMeteor on May 26, 2019, 03:54:43 AM
High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

This on the other hand makes tons of sense. I am acquainted with meteorology and know low pressure correlates to bad (not sunny) weather, like hurricanes, the worst case example of low pressure bad weather, and high pressure correlates to bluebird or at least fair weather cumulus clouds. 

I was more interested if there was something about the pressure itself that is bad for ice. Like does high pressure mean the air is at greater density, which would mean more heat transfer from the ice to the air.
Barometric pressure in and of itself really doesn't have any effect on the ice.

Further, heat transfer from air to ice is pretty negligible when compared to that from insolation or directly from the water - that's why melt ponds are so dangerous - they reduce albedo and put a layer of warm(relatively) water on the top surface of the ice which concentrates and transfers the heat quite efficiently.

The mechanics of the ice itself changes dramatically with temperature - ice at -20c is 4-5 times more structurally resistant to crushing and shear forces than ice at freezing ~ minus 1.8c for water in the Arctic.

But otherwise, air pressure in and of itself really doesn't alter the melt equation.

Thank you.
Title: Re: The 2019 melting season
Post by: be cause on May 26, 2019, 04:06:22 AM
and back to the weather up north .. and in reply to JDAllen's reply to me .. can you , or anyone , provide any references re ice floe size and side melt ?
   My observations are that the fracture form being taken is pretty fractal this year .. and I would suggest that already in areas like 83N 130W a large proportion of the floes are under 150m ...
   I assume that these zones appear darker on Worldview because less light is escaping .. am I right ?
   If so it is busy working out of sight ..
 
Please please put my concerns to rest .. I am convinced that in increasingly large parts of the Arctic basin the angle of sun and floe size will play a measurable and perhaps unexpectedly important part in the outcome this season .. b.c.

ps . same devastating scene across the pole at @ 83N 130E  Worth looking at both spots on Worldview on the 20th  .
Title: Re: The 2019 melting season
Post by: Pragma on May 26, 2019, 04:31:34 AM


Also not an expert, but I don't think comparing the Bering Strait to Fram Strait is very useful.The forces driving the ice to Fram are largely based on the Earth's spin which isn't changing. The circumpolar winds rotate clockwise and the powerful East Greenland Current is pulling Arctic surface water into the Atlantic.

The weather may accentuate the movement of ice toward Fram as winds pick up and ice melts and offers less resistance to the prevailing forces, but we shouldn't expect to see a lot of ice leaving via the Bering.

If any of the more expert contributors can weigh in on how a weather system like this can change the pace of ice export, that would be appreciated.

OK, good. This is useful but I am a little confused. If the dominant influence on ice movement is earth rotation, and Atlantic currents, it makes perfect sense that the majority of ice movement would be to the east.

At the same time, we all seem to agree that ice distribution can be affected greatly by prevailing winds, which seems contradictory.

Also, I was under the impression that the cyclone(s) of 2012 at the end of the melting season what what took the 2012 ASIE to a new low. I assumed that that was due to ice movement, but I now want to clear up any misconceptions I have. It may have just been the mechanical movement that boosted melting or delayed freeze-up?

So I guess a good way to put the question is:

What are the relative effects of weather patterns, currents and earth rotation  when it comes to ice movement out of the arctic and is it only observed in the east via Fram,  Nares, and between Svalbard and Novaya Zemlya?

Further, is the concern about the large stationary high in the Arctic more an issue of clear skies and higher temperatures? 
Title: Re: The 2019 melting season
Post by: b_lumenkraft on May 26, 2019, 06:07:02 AM

It's not confusing because it's complex. It's not even confusing.

So it's too complex for you to add a search term to your google search to get a non geology result, but the obviously extreme complexity of weather systems isn't? That makes no sense. You underestimate the complexity of the Arctic and overestimate your ability to use Google.


Quote
When someone wants to learn...

...they would ask a followup question if something is not understood. You opted for insulting many intelligent people instead.

Don't you dare using logic as an argument here ever again. Obviously, you don't understand the concept.
Title: Re: The 2019 melting season
Post by: Rich on May 26, 2019, 06:24:42 AM


Also not an expert, but I don't think comparing the Bering Strait to Fram Strait is very useful.The forces driving the ice to Fram are largely based on the Earth's spin which isn't changing. The circumpolar winds rotate clockwise and the powerful East Greenland Current is pulling Arctic surface water into the Atlantic.

The weather may accentuate the movement of ice toward Fram as winds pick up and ice melts and offers less resistance to the prevailing forces, but we shouldn't expect to see a lot of ice leaving via the Bering.

If any of the more expert contributors can weigh in on how a weather system like this can change the pace of ice export, that would be appreciated.

OK, good. This is useful but I am a little confused. If the dominant influence on ice movement is earth rotation, and Atlantic currents, it makes perfect sense that the majority of ice movement would be to the east.

At the same time, we all seem to agree that ice distribution can be affected greatly by prevailing winds, which seems contradictory.

Also, I was under the impression that the cyclone(s) of 2012 at the end of the melting season what what took the 2012 ASIE to a new low. I assumed that that was due to ice movement, but I now want to clear up any misconceptions I have. It may have just been the mechanical movement that boosted melting or delayed freeze-up?

So I guess a good way to put the question is:

What are the relative effects of weather patterns, currents and earth rotation  when it comes to ice movement out of the arctic and is it only observed in the east via Fram,  Nares, and between Svalbard and Novaya Zemlya?

Further, is the concern about the large stationary high in the Arctic more an issue of clear skies and higher temperatures?

While we wait for more expert input....

The prevailing winds are a function of the Earth's rotation. The Beaufort Gyre spins clockwise and puts the ice in a position to catch the current heading east.

The impact of a storm like the GAC can also include upwelling of warmer saltier water to the surface.

There is some non zero amount of ice exiting via the Bering, but it is small relative to the Atlantic side.

The strength of the export current is also due to salinity. The Atlantic is much saltier (and warmer) than the Arctic or Pacific. Where they meet, the lighter surface layer of the Arctic (where the ice is located) is