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Paul

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Re: The 2021 melting season
« Reply #1700 on: July 03, 2021, 10:28:20 AM »
A large area of weakness near 80N on the Pacific side has appeared now due to the dispersion caused by the low pressure system.  The same region had been hit by strong surface melting with warm winds and sunny conditions earlier in June, with some of the earliest start up of significant widespread surface melt I've seen (as diagnosed using channel 3-6-7 on MODIS).  Forecast now has more sun and warm air hitting that area.

If this region melts out then this year then the final extent will challenge the 2012 result.  Assuming everything on the Chukchi side of this region melts out, and that the Beaufort doesn't retain an unusually large amount of ice, following a slowish start in that region.  At least compared to the last 5 or so years.

Similar areas of weakness existed in 2012 and 2016 and looked somewhat worse in my opinion.

I just feel we are in a worse position than 2012 and 2016 imo, warm SSTS(apart from the Barants sea for now) dispersion appearing widely and a record retreat in the Laptev, fast ice falling apart and melting and the ice edge from the East Siberian Islands looks like record breaking in terms of how far it has retreated and with a mix of dipole and stormy weather forecast, its not looking good at all.

With the ESS falling apart, dread to think what the numbers could be once JAXA returns.

SimonF92

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Re: The 2021 melting season
« Reply #1701 on: July 03, 2021, 11:35:20 AM »
A bit of hyperbole never hurt anyone and I enjoy reading this thread every year (excluding the silly arguments), but if I had a penny for every time someone has said 'this is the year', i would be rich :).

Also, I don't think some people appreciate how much work Oren has keeping this thread clean for lurkers like me, no need to disrespect him/her when theyre doing everyone a favour
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oren

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Re: The 2021 melting season
« Reply #1702 on: July 03, 2021, 01:26:49 PM »
Thanks for the support Simon. But in all honesty I really would like to get back to the ice.

Asking whether this is "the year", obviously we can't know. But so far it's really been a tale of two sectors. The Siberian side, despite having had high winter volume, has been running at record or near record low area for a while now, and looks bad on satellite images. In high probability it will achieve a complete meltout, not a feat achieved every year even in the 2010s. Along with the rubble in the Atlantic-facing CAB it certainly looks to be a very bad year for the ice. OTOH the Chukchi and Beaufort have been running at near record high (in the AMSR2 dataset which began 2012), and along with the "Western" CAB which so far has been relatively protected it certainly looks to be a relatively mild year for the ice. The Chukchi will eventually melt out but the Beaufort could retain a nice amount, and it's hard to achieve a record without the Beaufort zeroing, a feat only achieved in half the years.
I am struck by how closely this Tale of two Sectors is following in 2020's footsteps.
Eventually it's the CAB that decides the fate of melting seasons. Only 3 years have managed to "break" the CAB relatively speaking, 2012 (light pink), 2016 (orange) and 2020 (blue/red). Will 2021 (black) be one of them? This mostly depends on July weather, and on the current thickness and state of the ice which are generally rather unknown.
Stay tuned.

Juan C. García

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Re: The 2021 melting season
« Reply #1703 on: July 03, 2021, 02:37:43 PM »
Good analysis, Oren. I only disagree in one point: I am not optimistic on Beaufort. If you see PIOMAS thickness, is not so good. We have seen that the Beaufort Gyre breaks the ice early, in other years. It did not happen on 2020 and 2021. But we are just starting July. We will have to see what will happen in the next two months. Even if Beaufort does not go to zero, we will have melting there.
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

nadir

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Re: The 2021 melting season
« Reply #1704 on: July 03, 2021, 02:45:03 PM »
Good analysis, Oren. I only disagree in one point: I am not optimistic on Beaufort. If you see PIOMAS thickness, is not so good. We have seen that the Beaufort Gyre breaks the ice early, in other years. It did not happen on 2020 and 2021. But we are just starting July. We will have to see what will happen in the next two months. Even if Beaufort does not go to zero, we will have melting there.

I was thinking the same. The current cyclonic pattern yields a bit or dissolves, and lets all that crazy NA overheated atmosphere flow onto the Beaufort sea ice and it could disappear “overnight” (being a bit hyperbolic here).

gerontocrat

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Re: The 2021 melting season
« Reply #1705 on: July 03, 2021, 02:55:58 PM »
For what it's worth attached is the Russian meteo temperature forecast for August, September, October 21. Above average warmth over all the Arctic Ocean along the Siberian shore.

Ok, it is long-term, but last year they were spot on. If they are right, if nothing else it could at least delay refreeze as happened last year.

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Aluminium

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Re: The 2021 melting season
« Reply #1706 on: July 03, 2021, 03:13:14 PM »
High Arctic AWP is close to average currently but there are 3 seas out of bounds.

Freegrass

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Re: The 2021 melting season
« Reply #1707 on: July 03, 2021, 03:35:48 PM »
Latest Five Day Forecast + Last 48h
Wind + Temp @ Surface
Large GiF!
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Pagophilus

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Re: The 2021 melting season
« Reply #1708 on: July 03, 2021, 03:50:57 PM »
June 28 - July 2.

2020.

It is interesting from watching your animation, Aluminium, that the main pack seems to have 'pulled in on itself' since June 28 rather than have been dispersed, as we are repeatedly reminded should happen in cyclonic conditions.

On the Pacific side, the pack boundary remains virtually stationary on your AMSR 2 animation.  On the Atlantic and Siberian sides, the boundaries mostly move towards the pole.  I do not think, from observation, this is due to melting back.  So why did the central pack ice not disperse?  Maybe because, looking BACK on Nullschool, while there was a strong LPS present prior to June 28, since June 28 conditions have not been so cyclonic at all (as others have noted here)? 

From Freegrass' Nullschool animation, the future weather patterns look uncertain.  And yes, I know the solstice is behind us and the CAB has been shielded from a lot of sunshine, but who knows what is coming?  And like oren I am intrigued by the amount of heat that will be arriving from Siberia.  The ESS fast ice might be in very poor shape in just three days or so...
« Last Edit: July 03, 2021, 04:06:31 PM by Pagophilus »
You may delay, but time will not.   Benjamin Franklin.

El Cid

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Re: The 2021 melting season
« Reply #1709 on: July 03, 2021, 04:45:18 PM »
... if I had a penny for every time someone has said 'this is the year', i would be rich :)

.....

At the beginning of June I also thought that this could be a record year and we would see the North Pole without ice. While that is still possible and I also understand that the "Russian" Seas are in very poor shape I also see that this year has already lost momentum and for the next 5-10 days nothing significant seems to be on the horizon. The Atlantic side could be very weak by end-Aug but all in all, the really interesting things will likely happen in October and November when (like the last years) the Arctic will be very slow to refreeze...

Paul

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Re: The 2021 melting season
« Reply #1710 on: July 03, 2021, 04:48:43 PM »
For what it's worth attached is the Russian meteo temperature forecast for August, September, October 21. Above average warmth over all the Arctic Ocean along the Siberian shore.

Ok, it is long-term, but last year they were spot on. If they are right, if nothing else it could at least delay refreeze as happened last year.

Its going to be well above average, its guaranteed too, no doubts Laptev will be quite late to freeze again, ESS is less certain as I believe the ocean is less deep and ice tends to melt out slower here.

I do think a record low is possible but even if not, the disperse nature of the ice does suggest the ice could look alot more like 2016 than it appeared to look in 2020 but with potentially a lower extent.

Basically the Laptev warmth of 2018 - the present day seems to be the equivalent of the Beaufort sea warmth and retreat of 2007-2012. Either way, not good news for the ice.

gerontocrat

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Re: The 2021 melting season
« Reply #1711 on: July 03, 2021, 05:45:44 PM »
Concerning a tiny fraction of the sea ice...

I've been looking at the sea ice in the Greenland Sea North of 75 as of July 2 and in previous years. It looks in worse condition than in those previous years.

There are two ice tongues almost at the top of the NE coast - this looks like the first year that they are so exposed to open water - and they are losing ice quite quickly. A little gif attached.

GFS forecasts show for some time above freezing temperatures on the entire East coast of Greenland with periods of above zero temperatures along the entire North Coast. Fram export looks like zero to the Greenland sea, with persistent light winds from the south along the coast.

It seems possible to me that sea ice area and extent in the Greenland Sea could approach zero this month. This would be a first.

Click gif to start & enlarge. Click maximise for full size. runs 6 times.
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Pagophilus

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Re: The 2021 melting season
« Reply #1712 on: July 03, 2021, 09:32:47 PM »
I am not sure of what is happening with this massive area of smoke from Siberian fires, but it seems to be rotating counterclockwise, becoming denser and to be possibly heading for the Laptev-ESS-NE Kara area. 

Small gif, 0.8 Mb.  Click to animate
« Last Edit: July 03, 2021, 09:38:22 PM by Pagophilus »
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Rod

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Re: The 2021 melting season
« Reply #1713 on: July 04, 2021, 12:11:50 AM »
Good analysis, Oren. I only disagree in one point: I am not optimistic on Beaufort. If you see PIOMAS thickness, is not so good. We have seen that the Beaufort Gyre breaks the ice early, in other years. It did not happen on 2020 and 2021. But we are just starting July. We will have to see what will happen in the next two months. Even if Beaufort does not go to zero, we will have melting there.

This is the place to watch over the next few weeks. The Beaufort is the one spot that looks pretty good right now. 

Toggling between yesterday and today using bands 3-6-7 makes it appear there might have even been a little bit of surface refreeze last night.

It is hard to say how thick the ice is. I don’t put as much faith in PIOMAS as a lot of others do.

However, if the Beaufort continues to hold out, that will be a good thing for the ice this year. Like Juan, I have my doubts as to whether or not that will happen.

But, everyday the Beaufort holds out during the peak insolation season, means those relatively southern waters are not going to be heating up as much. If those waters stay cool, that will help later in the season when that same water gets circulated northward by the Beaufort gyre.
« Last Edit: July 04, 2021, 12:25:31 AM by Rod »

nadir

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Re: The 2021 melting season
« Reply #1714 on: July 04, 2021, 01:01:00 AM »
This should not be taken at face value, just as a plausible scenario.

The last EC 12Z +240h (day 10) shows for the first time something similar to what I was taking about. The cyclone weakens a bit and moves toward the Asian side, and a ridge breaks into the Beaufort sea.

I repeat, this is just a plausible scenario, not a trustworthy forecast (not backed by GFS at all btw), just something to keep an eye on.

In the meantime, CAA will get very warm in a few days after the cyclone moves over, that’s for sure.

Paul

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Re: The 2021 melting season
« Reply #1715 on: July 04, 2021, 01:38:38 AM »
This should not be taken at face value, just as a plausible scenario.

The last EC 12Z +240h (day 10) shows for the first time something similar to what I was taking about. The cyclone weakens a bit and moves toward the Asian side, and a ridge breaks into the Beaufort sea.

I repeat, this is just a plausible scenario, not a trustworthy forecast (not backed by GFS at all btw), just something to keep an eye on.

In the meantime, CAA will get very warm in a few days after the cyclone moves over, that’s for sure.

Maybe its just me but we are seeing more or less that sort of pattern right here and right now. Definately a dipole of sorts and high pressure with warm air is certainly over the Beaufort sea at the moment and for the next few days at least

Yes a cyclone will dominate most of the basin but apart from perhaps limiting SSTS from rising too much in the Laptev I see no positives in the current model outlook. If the low weakens and become flabby then maybe but most runs don't go with that and a deep low hitting ice that is getting weaker and more disperse can't be a good thing really.

Rod

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Re: The 2021 melting season
« Reply #1716 on: July 04, 2021, 01:52:38 AM »

Maybe its just me but we are seeing more or less that sort of pattern right here and right now.  . . .

Below is the current GFS 3 day average. The dipole was stronger in yesterday’s run. This pattern has appeared repeatedly this melt season, but people have not talked about it like they would have in years past.

I was guessing it is because every year we have different people who are more active in the discussions, and everyone has their own idea about what is most important.

But, if you are saying the dipole pattern is important to you, I agree! I think the previous dipole patterns this year (even if not true dipoles) are the reason the ice is so bad inside 80 N north of the Beaufort and ESS.

Rod

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Re: The 2021 melting season
« Reply #1717 on: July 04, 2021, 04:52:56 AM »
I don’t know if this works or not.  I tried to test it on developers corner.

I put together a small clip comparing three key areas on July 3, 2012 to July 3, 2021.

Looking at it this way, it appears 2021 is way behind 2012. Unfortunately, I am having trouble uploading it to the forums. It is likely large so don’t click on it unless you have wifi. I am on an iPhone and it never plays .mov from this site.  I tried to convert to mp4 but I don’t think it worked.

However, I was able to view it on the test site by clicking the download icon in the upper right hand corner (for those of you on a computer this might not make any sense).

Anyway, I hope you can get it to play. It is an interesting comparison.

<I converted the mov to mp4 and attached it too. O>
« Last Edit: July 04, 2021, 09:20:04 AM by oren »

The Blob warned us

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Re: The 2021 melting season
« Reply #1718 on: July 04, 2021, 06:01:33 AM »
Zonal mean air temperatures over the CAB at 925mb (2,500ft/760m) are much cooler than in 2019 & 2020.

Despite the final warming of the northern polar vortex in 2021 being a sudden warming class event, coupling into the troposphere was largely absent. In 2019 and 2020, sudden final warmings did couple down into the troposphere and give an explanation for the high pressure & atmospheric ridging in the highest latitudes.

grixm

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Re: The 2021 melting season
« Reply #1719 on: July 04, 2021, 09:08:28 AM »
Brown smoke is pouring in over the ice

nadir

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Re: The 2021 melting season
« Reply #1720 on: July 04, 2021, 11:03:22 AM »
This should not be taken at face value, just as a plausible scenario.

The last EC 12Z +240h (day 10) shows for the first time something similar to what I was taking about. The cyclone weakens a bit and moves toward the Asian side, and a ridge breaks into the Beaufort sea.

I repeat, this is just a plausible scenario, not a trustworthy forecast (not backed by GFS at all btw), just something to keep an eye on.

In the meantime, CAA will get very warm in a few days after the cyclone moves over, that’s for sure.

Maybe its just me but we are seeing more or less that sort of pattern right here and right now. Definately a dipole of sorts and high pressure with warm air is certainly over the Beaufort sea at the moment and for the next few days at least

Yes a cyclone will dominate most of the basin but apart from perhaps limiting SSTS from rising too much in the Laptev I see no positives in the current model outlook. If the low weakens and become flabby then maybe but most runs don't go with that and a deep low hitting ice that is getting weaker and more disperse can't be a good thing really.
Yes. Not that warm yet for the Beaufort sea but you are probably right.

johnm33

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Re: The 2021 melting season
« Reply #1721 on: July 04, 2021, 11:24:06 AM »
Looking at pack rotation, the first [1.5mb] is ice cover a hindcast running from 28:06 - 04:07, the second [2.6mb] ice thickness beyond 3.5m is black runs from 27:06 - 10:07
From Copernicus
« Last Edit: July 04, 2021, 11:31:26 AM by johnm33 »

Freegrass

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Re: The 2021 melting season
« Reply #1722 on: July 04, 2021, 11:47:21 AM »
Brown smoke is pouring in over the ice
I don't think I've ever seen this much smoke in the air. The fires are really raging out of control now it seems. If all that black carbon gets dropped on the ice, it's gonna drop albedo a lot...

Just imagine living there.. :-[

More about this in the wildfires thread.
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Freegrass

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Re: The 2021 melting season
« Reply #1723 on: July 04, 2021, 02:27:29 PM »
Latest Five Day Forecast + Last 48h
Wind @ Surface
Temp @ 1000hPa
Large GiFS!

This new low is packing a whole lot of wind again... And also more heat.
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Glen Koehler

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Re: The 2021 melting season
« Reply #1724 on: July 04, 2021, 08:03:55 PM »
     Lacking the skill to interpret what effects different weather patterns will have on the ice, I just take what GFS generates for surface temperature anomalies, with additional looks at wind fields and how much clear sky there is.  Note that the anomalies shown in the attached GFS 1-day forecast are relative to the 1979-2000 average (i.e. 1990 median).  So with cumulative global warming since 1990 multiplied ca. 3X by Arctic amplification, you would expect a 1 to 2C positive anomaly everywhere all the time just from the 31-year difference between 1990 to 2021.  But that is not what the forecast shows.  Zero anomaly 1990 temps in 2021 is a very cool forecast.

     The rest of the 10-day GFS forecast is basically the same.  The ESS and Laptev get several bouts of warm surface temp. anomalies, a couple of rain events, and short periods of clear sky.  But for the rest of the ASI it looks like a continuation of low-intensity melt season weather, minimal surface temp anomalies, dominance by low to intermediate strength low pressure systems, and few breaks in the clouds for unimpeded solar insolation. 

     Combined with similar conditions for roughly the 2-3 weeks before the solstice, this forecast extending to 3 weeks past the solstice indicates that for the 6 week period centered on the solstice, i.e. the peak of annual/melt season insolation, conditions were not conducive for a high melt year.  The DMI 80N temperature chart has its problems, but is still a useful monitor of melt season intensity.  For the first time I can recall, it shows temperatures below the 1958-2002 average.

     Yet the 2021 stats for Extent/Area/Volume are not that far from record low levels.  I think this all means that 2021 is showing us what the ASI looks like in the best possible melt season conditions.  Not as dramatic as a horse race to beat the 2012 record lows, but equally as informative and therefore interesting. 
     
     2021 shows us how far ASI decline has progressed without much contribution from current melt year exaggeration.  2021 is the baseline from which all subsequent melt seasons will operate.  That may appear to be a foolish thing to say because of course EVERY year is the baseline for subsequent years.  But my point is that if the 2021 melt season continues to be undramatic without inflammatory episodes like the 2020 prolonged July high pressure clear sky system, then 2021 becomes a very useful demonstration for the best possible state of the ASI without strong current melt season influence.

     From that perspective, it seems pretty clear that the ASI is in terrible shape.  Near record lows without much push from current melt season weather indicate that other factors such as Atlantification and the systemic momentum of losses from thickness and structural degradation are still at work. 

     If 2021 levels for different seas serve as high-end brackets for what we can expect in the future, it gives us a reference point for what Extent/Area/Volume levels will result from the next year with strong melt season weather.  Based on the interval between strong melt seasons since 2007, and counting 2020 as a strong melt season, the next strong melt season is probably no more than 1-3 years away.  And with global warming continuing, the floor underneath each melt season continues to increase in intensity.
« Last Edit: July 04, 2021, 10:13:51 PM by Glen Koehler »
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gerontocrat

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Re: The 2021 melting season
« Reply #1725 on: July 04, 2021, 08:24:27 PM »
I await JAXA data to see if it matches NSIDC daily data because... (see attached graph)
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HapHazard

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Re: The 2021 melting season
« Reply #1726 on: July 04, 2021, 08:45:05 PM »
I like & generally agree a lot with your well-written post there, Glen K.

Then I see gero's chart above and think to myself "WTF"  :o
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oren

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Re: The 2021 melting season
« Reply #1727 on: July 04, 2021, 11:32:23 PM »
The surface temps within the Arctic ocean are pinned to the melting point of snow and sea ice, so no wonder temps show zero anomaly, as long as the ocean is mostly filled with ice.
When the fresh water cover drains from the ice I believe temps can even go slightly lower, giving the illusion of colder weather.
Looking at 2012 and 2021 so far, the differences in the DMI N80 chart are not impressive IMHO. Click to animate. Also please recall this chart mostly gives the temp around the Pole, not throughout the whole basin, due to its weird weighting method.
I could agree this melting season is not spectacular, but surface temps are not the way to prove it. I would also remind the persistent export to the Barents and Fram this spring, which put a dent in the Atlantic-facing CAB, and the massacre of ice in the CAB last year that probably left the ice more vulnerable than usual. Remember the terrible end-Aug North Pole photo from Mosaic.
OTOH good freezing weather in the second half of the freezing season, especially high Siberian volume due to ridging, and the not-spectacular melting conditions, should have given a much better outcome than the current lowest NSIDC extent on record (temporarily or not, doesn't matter).

Michael Hauber

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Re: The 2021 melting season
« Reply #1728 on: July 05, 2021, 12:10:29 AM »
Current conditions are suitable for fast reductions with a fair bit of heat some sun on the Pacific and very high wind driven transport away from the Siberian ice edge.  Might also be a bit of a move along for the Beaufort with some ridging and warmth and maybe a bit of wind driven transport, but nothing dramatic, just a possible speed up to something closer to average for recent years.

After a few days of this the ridge goes away, and the low spreads out and becomes weaker, so ideal conditions for ice retention with cool, clouds and not much dispersion or wind.  After this low pressure intensifies again.  Some runs have had some extreme incursions of heat and ridging in the second week, but current runs keep the low pressure controlling most of the Arctic and the extreme heat only on the very edge where it will only impact ice that is pretty much guaranteed to melt regardless.  Could be a more sustained slow down on the cards depending on how conditions in the extended forecast range actually play out. 
Climate change:  Prepare for the worst, hope for the best, expect the middle.

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Re: The 2021 melting season
« Reply #1729 on: July 05, 2021, 12:36:19 AM »
Isn't this melting season a confirmation of what I posted about before, that the ice edge is easy to melt because of the extra heat coming from the land, and that this is a new normal? Melting the CAB will be a lot harder. For that you need the "perfect weather", and more heat in the ocean...
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Rod

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Re: The 2021 melting season
« Reply #1730 on: July 05, 2021, 12:42:37 AM »
   
     Yet the 2021 stats for Extent/Area/Volume are not that far from record low levels.  I think this all means that 2021 is showing us what the ASI looks like in the best possible melt season conditions.  Not as dramatic as a horse race to beat the 2012 record lows, but equally as informative and therefore interesting. 
     
     2021 shows us how far ASI decline has progressed without much contribution from current melt year exaggeration.  2021 is the baseline from which all subsequent melt seasons will operate.  That may appear to be a foolish thing to say because of course EVERY year is the baseline for subsequent years.  But my point is that if the 2021 melt season continues to be undramatic without inflammatory episodes like the 2020 prolonged July high pressure clear sky system, then 2021 becomes a very useful demonstration for the best possible state of the ASI without strong current melt season influence.


I think this sums things up nicely.  While I don’t agree on what constitutes important melt factors in today’s Arctic Ocean. I agree with the sentiment that things have changed. We don’t need to rehash the arguments about clouds and ocean mixing to see that the current ice reacts differently to external forces than the ice of 10 to 20 years ago.

Each year the ice gets thinner and more fragmented. We can see it in the satellite images regardless of what the models say.

It does not take much to push the ice to the brink under these conditions.

Yesterday I posted a video showing how 2012 was far ahead of 2021 at this point in time. But, 2012 also had a much more cohesive ice sheet. The ice this year is fragmented and broken throughout the Arctic. It won’t take much for a little weather to melt that ice. 

It is kind of like a glass of ice water on a warm sunny day. If your cup is filled with big ice cubes it will stay cool for a long time.  But if it is filled with crushed ice, and you repeatedly pick it up and shake it, that ice is not going to last long.

2021 is the glass with crushed ice that is repeatedly getting swirled around.  Will it be a record breaker? Who knows? But that is not the important question. The important question is how many more years can the ice hold out when each year it starts off in a worse condition.

Ice can only thicken so much in a single season regardless of how cold it is. Thermodynamics controls that. All we have left in the Arctic is young ice. 

That is what makes this season so interesting. What will happen when we are not seeing conditions that have traditionally been thought necessary for melting.


Glen Koehler

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Re: The 2021 melting season
« Reply #1731 on: July 05, 2021, 12:47:09 AM »
<snip> The surface temps within the Arctic ocean are pinned to the melting point of snow and sea ice, so no wonder temps show zero anomaly, as long as the ocean is mostly filled with ice.
     I should have noted that GFS "surface" temperatures are not directly at the surface, but are air temperature at 2 meters.  While it is true that an ice-water mix will remain at 0C as long as there is ice present to absorb heat, that has not prevented the GFS 2M temperature anomalies from being 2C or greater during the melting season over large areas of the Arctic Ocean in past melting seasons, but this year it is mostly at or near 0C anomaly. 

       As noted, the ESS and Laptev get a few bouts of those positive 2M temperature anomalies but the 2M air temperature anomalies for the Arctic overall are as low as I can recall seeing them during melting season.  Compare the GFS July 5, 2020 0Z 2M air temp. anomaly forecast with July 5 0z this year.  Granted it is not the flaming red temp. anomalies that GFS can show during winter, but it does show warming over much more of the High Arctic in 2020.  That said, Barents and Greenland Seas are taking it on the chin in 2021.

     And while it refutes my own supposition that 2021 has been a low melt season, just to show that GFS 2M temp. anomalies can get well above 0, see the May 26 2021 GFS forecast in 3rd image.
« Last Edit: July 05, 2021, 01:32:32 AM by Glen Koehler »
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Paul

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Re: The 2021 melting season
« Reply #1732 on: July 05, 2021, 12:54:45 AM »
I await JAXA data to see if it matches NSIDC daily data because... (see attached graph)

I think it will because the ESS and Laptev ice has just spectacularly collapsed as long with the ice in the Greenland sea, maybe we will see a 200K drop on one of the days on JAXA?

I totally disagree with those who are saying it's not been a spectacular melt season because locally across Siberia yet again, it has been. I have never known a period where for the most part winds have blown more or less from the land masses so frequently in this region, the momentum started right at the end of May into June and especially during that record breaking warmth. Early snowcover melt most certainly helped also.

That said, as alluded too other areas have been cooler like the CAB but those warm SSTS from the Laptev will no doubt test this ice resilience especially if it does become diffused like in 2013/2016. Sadly I don't expect the Beaufort/Chukchi ice to hold up as it is at lower latitudes but at least if it holds up for most of the season then it could refreeze quicker. Same can't be said of the Laptev especially, refreeze will bound to be slow here again.

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Re: The 2021 melting season
« Reply #1733 on: July 05, 2021, 01:02:11 AM »
Brown smoke is pouring in over the ice
I don't think I've ever seen this much smoke in the air. The fires are really raging out of control now it seems. If all that black carbon gets dropped on the ice, it's gonna drop albedo a lot...

Conservatively, the area of dense/significant smoke is now around 2 million km2. (Note: the area tool put a pink overlay on the area I outlined -- so things are not so bad as this image indicates, at least).

As grixm and others have noted, the smoke is starting to move in part over the ice.  We might get lucky again, as we did last year when significant soot from vast Siberian fires did not seem to land on the ice, even though the smoke traveled over the ice, presumably at high altitude.  That was largely under a high pressure regime.  What it might be like under a low pressure regime I do not know.  Does anyone?  Will water nucleate around the soot particles and bring them down in rain?  Or is the soot at too high an altitude?
« Last Edit: July 05, 2021, 01:11:20 AM by Pagophilus »
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jdallen

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Re: The 2021 melting season
« Reply #1734 on: July 05, 2021, 01:53:12 AM »
Brown smoke is pouring in over the ice
I don't think I've ever seen this much smoke in the air. The fires are really raging out of control now it seems. If all that black carbon gets dropped on the ice, it's gonna drop albedo a lot...

I'll have to go back through some of my captured images, but I recall seeing this bad previously. 

IIRC it *was* later in the season however.

They heat is getting things off to an early start.
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Paul

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Re: The 2021 melting season
« Reply #1735 on: July 05, 2021, 02:21:34 AM »
Brown smoke is pouring in over the ice
I don't think I've ever seen this much smoke in the air. The fires are really raging out of control now it seems. If all that black carbon gets dropped on the ice, it's gonna drop albedo a lot...

I'll have to go back through some of my captured images, but I recall seeing this bad previously. 

IIRC it *was* later in the season however.

They heat is getting things off to an early start.

2018 at this time of year saw alot of smoke coming in from Siberia but it did not seemed to of affected the ice in any negative way and I'm not actually convinced it really does affect the ice. It's just not nice too see on the satalite images mind.

Pagophilus

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Re: The 2021 melting season
« Reply #1736 on: July 05, 2021, 04:21:58 AM »
And this from Gerontocrat on the extent and area thread...

Meanwhile, the last two days daily sea ice extent losses of 582k (NSIDC daily data) propel Sea Ice Extent to lowest in the satellite record (while sea ice area lags by about 0.5 million km2). What will the JAXA data say?

 :o 

NSIDC sea ice comparison tool allows for a view of how 3 July 2021 extent compares with 3 July 2020...   
« Last Edit: July 05, 2021, 04:30:28 AM by Pagophilus »
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VeliAlbertKallio

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Re: The 2021 melting season
« Reply #1737 on: July 05, 2021, 05:35:07 AM »
The sea ice of the Arctic Ocean was much less fragmented with less surface area of fissures (at least in the early summer) in the past. I have few good colour images here (using the-then-novel and revolutionary multiplex satellite imaging by a cluster of satellites to remove clouds) in early 2000's when ice was still strong showing (whole Arctic Ocean surface exposed, except fast moving ice on Greenland Sea). 1st Parliament evidence pp. 21-24. Also, page 7 shows manifestation of the intensity of heat exchange between sea water and sea ice at its most extreme end. https://www.academia.edu/45128583/MPs_to_review_UKs_role_in_Arctic_sustainability_Pdf_Edition_of_Parliamentary_Evidence_pdf Thus, the more fissures and ice fragmentation occurs, the more 3-dimensional surface there is for direct heat exchange between ice and sea water. Salt penetrating into fissures and saline sea water licking edges of ice floes, melting intensifies as heat is more transferred. Increased transportation (floe movement within sea water) and warming of sea water in leads, breaking effect of waves all make it soon to one slush pile of rotten ice. 
<snip>

I think this sums things up nicely.  While I don’t agree on what constitutes important melt factors in today’s Arctic Ocean. I agree with the sentiment that things have changed. We don’t need to rehash the arguments about clouds and ocean mixing to see that the current ice reacts differently to external forces than the ice of 10 to 20 years ago. Each year the ice gets thinner and more fragmented. We can see it in the satellite images regardless of what the models say. It does not take much to push the ice to the brink under these conditions.

Yesterday I posted a video showing how 2012 was far ahead of 2021 at this point in time. But, 2012 also had a much more cohesive ice sheet. The ice this year is fragmented and broken throughout the Arctic. It won’t take much for a little weather to melt that ice. It is kind of like a glass of ice water on a warm sunny day. If your cup is filled with big ice cubes it will stay cool for a long time.  But if it is filled with crushed ice, and you repeatedly pick it up and shake it, that ice is not going to last long.

2021 is the glass with crushed ice that is repeatedly getting swirled around.  Will it be a record breaker? Who knows? But that is not the important question. The important question is how many more years can the ice hold out when each year it starts off in a worse condition. Ice can only thicken so much in a single season regardless of how cold it is. Thermodynamics controls that. All we have left in the Arctic is young ice. That is what makes this season so interesting. What will happen when we are not seeing conditions that have traditionally been thought necessary for melting.
« Last Edit: July 05, 2021, 05:45:06 AM by VeliAlbertKallio »
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Freegrass

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Re: The 2021 melting season
« Reply #1738 on: July 05, 2021, 08:39:02 AM »
HYCOM 2020 vs 2021
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Freegrass

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Re: The 2021 melting season
« Reply #1739 on: July 05, 2021, 09:08:24 AM »
HYCOM 2020 vs 2021
The "Beaufort arm" - that didn't melt out last year - is already visible on last year's HYCOM image. So I wonder if the last of the thick MYI ice - that was transported into the Beaufort sea during winter, and is clearly visible right now - will melt out this year. I have my doubts... And if it doesn't melt out, it'll go back into the Beaufort gyre - just like it did in "the good ol' days" - and be saved to live on for a few more seasons...
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Aluminium

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Re: The 2021 melting season
« Reply #1740 on: July 05, 2021, 09:58:51 AM »
June 30 - July 4.

2020.

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Re: The 2021 melting season
« Reply #1741 on: July 05, 2021, 10:20:28 AM »
Interestingly it seems melting momentum has picked up in early July, mirroring what happened in 2020, when it pulled clear of the rest of the field in extent statistics. So "good weather for ice retention" - we still have to wait and see it materialize. But there is still some melting in peripheral seas + the Russian coastal side is collapsing now. We have to wait until the Russian side clears and then we will see, how protected the CAB and Beaufort are and how protective weather has been for the ice. Then perhaps it would be reflected in statistics too, or not.

Freegrass

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Re: The 2021 melting season
« Reply #1742 on: July 05, 2021, 11:00:21 AM »
Interestingly it seems melting momentum has picked up in early July, mirroring what happened in 2020, when it pulled clear of the rest of the field in extent statistics. So "good weather for ice retention" - we still have to wait and see it materialize. But there is still some melting in peripheral seas + the Russian coastal side is collapsing now. We have to wait until the Russian side clears and then we will see, how protected the CAB and Beaufort are and how protective weather has been for the ice. Then perhaps it would be reflected in statistics too, or not.
Which melting momentum? There is none! All I see is ice being blown to the north by powerful winds coming off Siberia, compacting the ice again. That's what's dropping the numbers right now.

There is no collapse of Russian coastal ice. All it did was detach from the coast and break up. But the ice that broke up in the ESS is still very thick, and I don't think this ice will melt out this season. It's much to thick for that, and the ocean is still too cold due to a lack of sunshine.

Even the open water in the Laptev is constantly covered in clouds, which means it's not heating up much, and thus "melting momentum" will come to a quick end at the end of the season. There will be no continued bottom melting like we saw last year. And thus I think we'll not even end up in the top ten this year. Heck, it's even gonna be hard to stay in the top 15 IMHO...

Ice in the ESS, Chukchi, and Beaufort sea is way to thick to melt out, and the Atlantic side has completely recovered. So I don't see any part of the Arctic Basin that's in danger of collapse right now. I even doubt that the Kara sea will completely melt out this year...

So there is no melt momentum. What we have is a recovery year, because even if the sun would come out next week, peak insolation will have past 3 weeks ago by then, and so the power of the sun is diminishing, with lots and lots of very thick ice left al over the basin in very cold water that wasn't able to heat up much...

I say we end up outside the top 10, and next year, we'll start off the season with a whole lot of extra thick ice... Unless of course we have a winter like last year with a whole lot of Fram export...
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Niall Dollard

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Re: The 2021 melting season
« Reply #1743 on: July 05, 2021, 11:23:53 AM »
I am having no luck accessing the Barrow webcam of late.

But after having been clear of fast ice nearly 2 weeks ago, pack ice returned to Utqiagvik at the end of June and has since drifted a little north again. This is the sentinel image on July 4th. 
« Last Edit: July 05, 2021, 01:30:51 PM by Niall Dollard »

uniquorn

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Re: The 2021 melting season
« Reply #1744 on: July 05, 2021, 12:10:13 PM »
There is no collapse of Russian coastal ice. All it did was detach from the coast and break up. But the ice that broke up in the ESS is still very thick, and I don't think this ice will melt out this season. It's much to thick for that, and the ocean is still too cold due to a lack of sunshine.

The data tends to refute that supposition.
wipneus amsr2-uhh 3.125km extent, ESS

Freegrass

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Re: The 2021 melting season
« Reply #1745 on: July 05, 2021, 12:40:15 PM »
There is no collapse of Russian coastal ice. All it did was detach from the coast and break up. But the ice that broke up in the ESS is still very thick, and I don't think this ice will melt out this season. It's much to thick for that, and the ocean is still too cold due to a lack of sunshine.

The data tends to refute that supposition.
wipneus amsr2-uhh 3.125km extent, ESS
No it doesn't. We're right on the 2017 blue line, where it didn't melt out completely...

I know it's a bold claim, but I look at the ice, not the data. And what I see is very thick ice, and very little sunshine...

We won't know what the rest of the season will bring of course, but the very unreliable long term forecast is showing more LPSs until July 21. So my claim is bold, but not unfounded. 3m thick ice is a VTFIC (Very Thick Freaking F...ng Ice Cube), and I just don't see it melting out... It'll probably drift north, and join the rest of the pack. So that might clear the ESS. But I don't see it melting...

I starting this season by saying that the ESS, Chukchi, and Beaufort seas were filled with thick ice that would be hard to melt out. And then I got confused by reading this thread and thought we could still break records. But now I'm back to where I started. The Pacific side is gonna be tough to melt out. Especially with the weather we've had.

Now we wait to see if I got it right...
It'll be a good lesson...  ;)
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Re: The 2021 melting season
« Reply #1746 on: July 05, 2021, 12:42:41 PM »
(snip)

There is no collapse of Russian coastal ice. All it did was detach from the coast and break up. But the ice that broke up in the ESS is still very thick, and I don't think this ice will melt out this season. It's much to thick for that, and the ocean is still too cold due to a lack of sunshine.

(snip)

Ice in the ESS, Chukchi, and Beaufort sea is way to thick to melt out, and the Atlantic side has completely recovered. So I don't see any part of the Arctic Basin that's in danger of collapse right now. I even doubt that the Kara sea will completely melt out this year...

(snip)

I hope to not do any fault by assuming, that those assumptions are mainly based on the HYCOM thickness model.

I think, especially the ESS ice, but also the Chukchi might be a nice benchmark on the correctness.

The current AMSR2 map kind of disagrees a bit in the ESS region and also renders the Beaufort and CAA more vulnerable than the HYCOM thickness hints. But this could be of course only due to clouds or meld ponds on very thick ice.


(snip) but I look at the ice, not the data. (snip)
Aren’t you looking at ice models?  ;)

uniquorn

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Re: The 2021 melting season
« Reply #1747 on: July 05, 2021, 12:44:10 PM »
Quote
No it doesn't. We're right on the 2017 blue line, where it didn't melt out completely...
Accepted, though Siberia was a lot cooler in 2017 ....edit though perhaps not the ESS
« Last Edit: July 05, 2021, 01:02:43 PM by uniquorn »

Pagophilus

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Re: The 2021 melting season
« Reply #1748 on: July 05, 2021, 12:47:48 PM »
There is no collapse of Russian coastal ice. All it did was detach from the coast and break up. But the ice that broke up in the ESS is still very thick, and I don't think this ice will melt out this season. It's much to thick for that, and the ocean is still too cold due to a lack of sunshine.

The data tends to refute that supposition.
wipneus amsr2-uhh 3.125km extent, ESS
Latest AMSR 2 image for July 4 also tends to argue against your assertion, Freegrass (can't use Worldview, as there are clouds over parts of the Siberian side today and yesterday).  Can't speak to the thickness of the ice in the ESS but it sure fractured and crumbled very quickly.  The Laptev and SW Kara are history and the ESS is very much smaller area than it was.  Only the NE Kara is still in any sort of reasonable shape IMO.
« Last Edit: July 05, 2021, 01:32:17 PM by Pagophilus »
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be cause

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Re: The 2021 melting season
« Reply #1749 on: July 05, 2021, 01:23:38 PM »
  Pagophilus :'Only the NE Kara is still in any sort of reasonable shape IMO.' to me seems a true and accurate assessment of the entire 'high Arctic' .
  Gerontocrat :- Extent is at position #1 in the satellite record ! .. thank goodness we were warned to expect a stall .
  Could we all get back to observing an exciting and different season and bear it witness rather than asserting such nonsense as 'there is no collapse of russian coastal ice.' ? Just look at WV from 1st - 3rd July . Does it just magically disappear before our eyes ? b.c.
 
 
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