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Daniel B.

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Re: The 2018 melting season
« Reply #200 on: April 03, 2018, 01:16:02 AM »
Heck, the cluster of 4 record highs in a 6 year span from 2008 to 2014 seems to suggest we are moving towards more ice coverage not less.
What record highs? As far as I can tell, the highs for all of those years were below the median high.

Look at the graph that Neven posted immediately prior.  The four highest years for Bering sea ice March average ice area were 2012, 2008, 2010, 2013.  His comment about an outlier may prove to be quite accurate, similar to 1989.

snrjon

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Re: The 2018 melting season
« Reply #201 on: April 03, 2018, 07:49:48 AM »
Hi, noob question. Arctic sea ice volume increases until mid-April, while the sea ice extent typically peaks a month or so earlier. Melting from the edges is a very obvious cause of extent decrease, but what are the mechanisms that allow growth in volume for a month after the melting begins? Is it addition by freezing to the bottom surface, tectonic squeezing, snow, and what is the most important of these? Thanks for any pointers.

oren

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Re: The 2018 melting season
« Reply #202 on: April 03, 2018, 07:54:08 AM »
Hi, noob question. Arctic sea ice volume increases until mid-April, while the sea ice extent typically peaks a month or so earlier. Melting from the edges is a very obvious cause of extent decrease, but what are the mechanisms that allow growth in volume for a month after the melting begins? Is it addition by freezing to the bottom surface, tectonic squeezing, snow, and what is the most important of these? Thanks for any pointers.
Hi snrjon, I've answered you in the "stupid" questions thread (though I do dislike the name - should be "beginner" questions or whatever). https://forum.arctic-sea-ice.net/index.php/topic,143.msg148292.html#msg148292
« Last Edit: April 03, 2018, 08:04:26 AM by oren »

Neven

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Re: The 2018 melting season
« Reply #203 on: April 03, 2018, 09:49:13 AM »
Hi snrjon, I've answered you in the "stupid" questions thread (though I do dislike the name - should be "beginner" questions or whatever). https://forum.arctic-sea-ice.net/index.php/topic,143.msg148292.html#msg148292

There's nothing wrong with a good stupid question.  ;D
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oren

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Re: The 2018 melting season
« Reply #204 on: April 03, 2018, 10:29:20 AM »
Hi snrjon, I've answered you in the "stupid" questions thread (though I do dislike the name - should be "beginner" questions or whatever). https://forum.arctic-sea-ice.net/index.php/topic,143.msg148292.html#msg148292

There's nothing wrong with a good stupid question.  ;D
I know, stupid is not to ask. But maybe at least change the thread title to "Stupid" questions?

Neven

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Re: The 2018 melting season
« Reply #205 on: April 03, 2018, 10:49:39 AM »
Okay, done.  :)
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uniquorn

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Re: The 2018 melting season
« Reply #206 on: April 03, 2018, 12:55:36 PM »
It won't be long ebefore the last ice in the Bering Sea gives up the ghost, and the Chukchi Sea doesn't look good. A lot of the ice there must be pretty thin, given that there was open water and sub 0.5m ice only 6 weeks or so ago
Also to factor, we are with in a week or so of reaching "break even" where incoming insolation will balance outgoing long wave radiation from the top of the atmosphere.  The current predicted spasm of inflowing heat will only exacerbate the problem.
Agreed. Bering/Chukchi Jan-Mar29
amsr2 uni-hamburg

Pmt111500

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Re: The 2018 melting season
« Reply #207 on: April 03, 2018, 01:27:53 PM »
It won't be long ebefore the last ice in the Bering Sea gives up the ghost, and the Chukchi Sea doesn't look good. A lot of the ice there must be pretty thin, given that there was open water and sub 0.5m ice only 6 weeks or so ago
Also to factor, we are with in a week or so of reaching "break even" where incoming insolation will balance outgoing long wave radiation from the top of the atmosphere.  The current predicted spasm of inflowing heat will only exacerbate the problem.
Agreed. Bering/Chukchi Jan-Mar29
amsr2 uni-hamburg

Again looking like there'd be some pumping action at lunar tempo here but it can't be, can it. ~29 days between local minimums. Noo, it wouldn't, would it?
Cooling the outside by heat pump.

oren

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Re: The 2018 melting season
« Reply #208 on: April 03, 2018, 02:11:02 PM »
Thanks for the animation uniquorn. Very interesting to watch. It does seem that the "native" air temps are sufficient for surface freezing, but heat coming from elsewhere on the wings of the south winds is what gets the ice. As this happened several times this winter, and the ice was too thin to resist, we got the record result.

uniquorn

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Re: The 2018 melting season
« Reply #209 on: April 03, 2018, 02:54:53 PM »
I expect sea surface temperature and wave action doesn't help.
Nice view on Worldview today

Terra Modis

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Re: The 2018 melting season
« Reply #210 on: April 03, 2018, 03:20:02 PM »
Hi snrjon, I've answered you in the "stupid" questions thread (though I do dislike the name - should be "beginner" questions or whatever). https://forum.arctic-sea-ice.net/index.php/topic,143.msg148292.html#msg148292

There's nothing wrong with a good stupid question.  ;D

Thanks for the answer. Question prompted by noting the DMI volume graph, where there is maybe another 2000-3000 cubic km to reach the peak, before net volume melting takes over.

guygee

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Re: The 2018 melting season
« Reply #211 on: April 03, 2018, 03:40:05 PM »
Again looking like there'd be some pumping action at lunar tempo here but it can't be, can it. ~29 days between local minimums. Noo, it wouldn't, would it?
Worth checking out but tides vary only about 1 foot Norton Sound Nome AK,
https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=9468756

A-Team

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Re: The 2018 melting season
« Reply #212 on: April 03, 2018, 04:06:37 PM »
Quote
Usually you see a bit of sea-ice along the coasts .... on March 27 in for a shock flew his drone and recorded astonishing footage of sea ice stretching over Brighton, Newfoundland 
They don't have internet? Maybe the mp4 below would help, it is an easy daily update. It runs from the first of the year to April 3rd, showing Jaxa, Jaxa inverted, OSI-SAF drift, and AMSR2 sea ice concentration. The town of Brighton NL is marked with a star. Note how Fram ice goes around the tip of south Greenland but almost immediately melts out in the Irminger Current.

This is a quite interesting, easily readable article on Baffin Bay sea ice for 2017

Increasing Mobility of High Arctic Sea Ice Increases Marine Hazards Off the East Coast of Newfoundland
DG Barber et al
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL076587 open source

During spring 2017 an anomalous ice cover composed of MYI from the High Arctic presented hazardousconditions off the northeast coast of Newfoundland. The ice cover was thicker than is typical of the area and as a result persisted into late June when the area is typically ice-free and maritime traffic can proceed unimpeded by sea ice.

The influence of storm events is compounded by a low internal ice stress field that makes the ice cover more responsive to winds and fosters peak ice drift speeds of up to 75 km/day.

These MYI floes were advected over 3,000 km from the Lincoln Sea and CAA to the coastal waters around Newfoundland within one ice season. Based on tracking the MYI edge, we determine that MYI must enter Baffin Bay through Lancaster Sound between early October and mid-January or enter Nares Strait from the Lincoln Sea between September and December in order to be transported to Newfoundland before the ice edge begins to retreat in early May.

Under a changing climate, the Arctic ice pack has become increasingly mobile, with increased ice drift speeds and increased ice export through narrow channels due to the
reduced likelihood of ice arch formation.
« Last Edit: April 04, 2018, 01:19:55 PM by A-Team »

Pmt111500

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Re: The 2018 melting season
« Reply #213 on: April 03, 2018, 04:37:53 PM »
Again looking like there'd be some pumping action at lunar tempo here but it can't be, can it. ~29 days between local minimums. Noo, it wouldn't, would it?
Worth checking out but tides vary only about 1 foot Norton Sound Nome AK,
https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=9468756
Thanks for the info. I've seen tides in northern Norway and they're not hugely variable either. The tidal influence on coastal ice should be checked areally as they're of course opposite of each other twice á day. It's possible you can't rely solely on satellites on this as they do not go over at the same area at the same times wrt moon. I've often seen this sort of periodicity seemingly occurring in ice data only to lose it after a couple of months. Common sense would say there is some effect as the high tide would expose more of the ocean under ice but how big the effect would be I've got no idea.
« Last Edit: April 03, 2018, 05:04:28 PM by Pmt111500 »
Cooling the outside by heat pump.

oren

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Re: The 2018 melting season
« Reply #214 on: April 03, 2018, 06:43:29 PM »
Thanks for the answer. Question prompted by noting the DMI volume graph, where there is maybe another 2000-3000 cubic km to reach the peak, before net volume melting takes over.
BTW, I find the DMI volume suspect, and much prefer PIOMAS. You can watch Wipneus' latest animation for March to see where PIOMAS thinks the volume is growing. https://forum.arctic-sea-ice.net/index.php/topic,119.msg148336.html#msg148336

jdallen

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Re: The 2018 melting season
« Reply #215 on: April 03, 2018, 10:35:25 PM »
Bering Strait, today.  This is definitively *bad*.

 :o
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Neven

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Re: The 2018 melting season
« Reply #216 on: April 03, 2018, 10:58:51 PM »
There it finally is, 1051 hPa over the Beaufort. I'll post the forecast tomorrow. It looks like 1030+ hPa will remain a feature over the CAB for the week to come, with potentially a 974 hPa cyclone coming in via Kara. That should speed up transport towards the Atlantic. Not to mention all that sunshine over the Central Arctic. The Sun's probably too low to cause any melt onset, but still... Interesting set-up.
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TerryM

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Re: The 2018 melting season
« Reply #217 on: April 04, 2018, 05:22:50 AM »
" 'Usually you see a bit of sea-ice along the coasts and if you happen to fly the drone far enough, you may capture some icebergs much further away' Beyzaei told Global News. So Beyzaei was in for an early April Fool's shock on March 27, when he flew his drone off the Newfoundland coast and recorded astonishing footage of sea ice stretching over Brighton, Newfoundland, Global News reported Sunday. "

'Stunning Drone Video of Sea Ice Reveals Unexpected Climate Change Effects'
"..the Arctic has just experienced its warmest winter on record. Arctic sea ice also reached its second-lowest extent on record this year, just barely inching out 2017's ice coverage to avoid being the lowest year for Arctic sea ice ever.
But according to research published in Geophysical Research Letters on March 15 and cited by Global News, footage like Beyzaei's is exactly what you can expect from the impacts of climate change on the Arctic."


https://www.ecowatch.com/sea-ice-drone-newfoundland-2555583953.html


FWIW
I spent the last week in May of 2006 ferrying between Northern Newfoundland and Southern Labrador. Tee shirt weather, no snow or ice visible on either side of the Strait of Bell Isle. On our first day in Labrador one small iceberg was spotted.
We had driven through southern Newfoundland in early May and again warm spring weather with no hint of ice.
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Terry

TerryM

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Re: The 2018 melting season
« Reply #218 on: April 04, 2018, 05:39:56 AM »
Again looking like there'd be some pumping action at lunar tempo here but it can't be, can it. ~29 days between local minimums. Noo, it wouldn't, would it?
Worth checking out but tides vary only about 1 foot Norton Sound Nome AK,
https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=9468756
Thanks for the info. I've seen tides in northern Norway and they're not hugely variable either. The tidal influence on coastal ice should be checked areally as they're of course opposite of each other twice á day. It's possible you can't rely solely on satellites on this as they do not go over at the same area at the same times wrt moon. I've often seen this sort of periodicity seemingly occurring in ice data only to lose it after a couple of months. Common sense would say there is some effect as the high tide would expose more of the ocean under ice but how big the effect would be I've got no idea.


Ungava Bay Canadian arctic - tidal range - 32.0 ft. 2nd highest in the world
Cook Inlet Alaska USA - tidal range - 30.3 ft. 4th highest in the world
Hudson Strait - Canadian Arctic - tidal range - >30 ft


My experience is that during melt season ~2 days after a strong spring tide lots of ice will break away from it's fast connection to shore.


Terry

romett1

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Re: The 2018 melting season
« Reply #219 on: April 04, 2018, 08:56:51 AM »
Bering Strait, today.  This is definitively *bad*.

 :o
As many have pointed out at some point looking at sea surface temperature anomaly chart (Bering Sea and surrounding waters) is even more interesting. Image: http://polar.ncep.noaa.gov/sst/ophi/

RikW

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Re: The 2018 melting season
« Reply #220 on: April 04, 2018, 09:01:46 AM »
That isn't really that surprising, since surface temperature won't really get above 0 when there is ice, and now it's gone earlier, so when ice is retreating faster than normal, you see huge temperature anomalies during that abnormally ice-free period

Neven

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Re: The 2018 melting season
« Reply #221 on: April 04, 2018, 02:09:02 PM »
For those who haven't seen the 2018 sea ice area and extent data thread today, JAXA had a big 137K drop (largest March daily drop in the 2005-2018 period), which means 2018 is now lowest on record:
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Neven

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Re: The 2018 melting season
« Reply #222 on: April 04, 2018, 02:12:08 PM »
As for that ECMWF forecast (provided by Tropical Tidbits), that low is now at D5 at 972 hPa, and over the Barentsz, not Kara, but will impact Kara most. And as said, lots of high pressure over the CAB. The Arctic is extremely lucky it isn't mid-May yet:
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Neven

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Re: The 2018 melting season
« Reply #223 on: April 04, 2018, 02:13:43 PM »
And, last but not least, I've prepared temperature graphs for the PIOMAS update, and as expected, March was plenty cold:
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A-Team

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Re: The 2018 melting season
« Reply #224 on: April 04, 2018, 03:19:03 PM »
Quote
March was plenty cold
But not cold enough to freeze the Arctic Ocean at 82º north of Svalbard which now has open water for the entire year, mid-winter dates of 01 Dec 2017 to 03 Apr 2018 shown in 4 satellite views below (124 days of UH AMSR2, Jaxa-, Ascatsep, Ascatuj).

Had it not been for strong and persistent winds in March that pushed ice towards the Barents Line, the blue ocean event would have been far more extensive in area, not so much northward as zonally because of how Atlantic Waters continue eastward along the continental shelf edge. Modis VIIRS gives an idea of how much more extensive open water would have been with more typical anti-cyclonic winds.

The St Anna Trough will play a key role in somewhat delaying progression of open water past FJL to SZ. There's a good discussion of the oceanographic data there in:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JC010804 free full

The Chukchi has some open water for two-thirds of the year, greatly exceeding 'seasonally ice-free' but some of this is icepack lift-off rather than warm water overwhelming ice formation.

We may need to re-examine the notion that the Arctic Ocean will re-freeze in winters after 'blue ocean' summers. That may still be true north of the CAA and for central Arctic Ocean to Siberia but since it's already wrong along above the Barents Line and almost wrong in the Chukchi-Beaufort region, it's hard to see how (inevitable) further warming will bring freeze-over to areas not freezing over now.

« Last Edit: April 04, 2018, 04:07:35 PM by A-Team »

numerobis

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Re: The 2018 melting season
« Reply #225 on: April 04, 2018, 03:46:49 PM »
The storm forecast on Baffin actually happened: Monday saw strong southeasterly winds (sustained > 50 km/h, gusts > 90 km/h) under generally bright sun with periods of light precipitation, some of it probably rain (hard to tell when it's flying by so fast). The previous two days had seen moderate (40 gusting to 60) northwesterlies over the sea ice (but not much on land, it was quite localized).

Monday's storm came with above-freezing temperatures, and it's been far above normal and is forecast to stay that way for a few days yet with bright sun.

There's been a lot of snow lately by local standards -- about a foot over the Easter weekend, when 5-10cm rates us a snowfall warning.

I see the Baffin ice area bumped up a bit with the northwesterlies (presumably mostly from pushing ice down from the high arctic into the open sea), then fell a bit with the southeasterlies (pushing it back up North, or piling it up against shore).

Lord M Vader

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Re: The 2018 melting season
« Reply #226 on: April 04, 2018, 05:32:52 PM »
NEVEN: I'm sorry, but I've to ask... You said in your earlier post that todays century drop (JAXA) is the biggest March drop but it's April now.... Is your statement true for April or was it just so for March 2005-2018?

Sincerely, LMV

Neven

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Re: The 2018 melting season
« Reply #227 on: April 04, 2018, 05:36:46 PM »
Sorry, I meant April!  ::)  :-X
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TerryM

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Re: The 2018 melting season
« Reply #228 on: April 04, 2018, 06:04:46 PM »
A-Team
WoW!


I'm sure that's a first since I've been watching, and probably some millennia longer, (the year round blue water north of Svalbard). Do you think it's atmospheric temperatures, a misguided North Atlantic Drift, an increasingly warm NAD, or an increasingly powerful NAD.


There were photos a few years back of researchers relaxing in bathing suits on the southern shores of Svalbard, but it only lasted a short time.


I recall that last year the WAW's were reported as rising off Newfoundland and disturbing the shallow fish habitat. Could this have pushed so far north?


Terry

Dharma Rupa

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Re: The 2018 melting season
« Reply #229 on: April 04, 2018, 07:06:47 PM »
We may need to re-examine the notion that the Arctic Ocean will re-freeze in winters after 'blue ocean' summers. That may still be true north of the CAA and for central Arctic Ocean to Siberia but since it's already wrong along above the Barents Line and almost wrong in the Chukchi-Beaufort region, it's hard to see how (inevitable) further warming will bring freeze-over to areas not freezing over now.

What data do we have on water overturning that far north?  All I've seen recently are some tantalizing buoy data from much further south.

romett1

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Re: The 2018 melting season
« Reply #230 on: April 04, 2018, 07:18:45 PM »
Webpage was down (or didn't update) for some days. Here is Apr 03 vs Mar 29. Images: ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/
« Last Edit: April 04, 2018, 07:28:32 PM by romett1 »

A-Team

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Re: The 2018 melting season
« Reply #231 on: April 04, 2018, 07:19:04 PM »
Quote
a first since I've been watching, and probably some millennia longer, (the year round blue water north of Svalbard). Do you think it's atmospheric temperatures, North Atlantic Drift
Right. Not so long ago, the Barents was largely solid ice in mid-winter. Not unreasonably as it is entirely above the Arctic Circle, it is still formally included in the Arctic Ocean by international committee.

That seems bizarre to people coming onto the scene in recent years. The annual 'blue ocean event' is now such a non-event that the goal posts for BOE were moved to the AO proper with few players even noticing. In a few years, they will be moved again to the CAA and Central Arctic. The ice we see in the Barents today has been blown in from the Kara and adjacent Arctic Ocean.

Causation? It's a mix. Mercator Oceans take on surface water temperatures is shown below. The just-above-freezing temperature of sea water has been recolored purple to draw out other areas that are not as drastically warmed as the direct Atlantic Water inflows above Svalbard.

The main anomaly shows the West Spitzbergen Current that runs counter to the East Greenland Current, rounds the corner at the Yermak Plateau and continues east along the shelf break. Note  much more warm water is present at the minimum 15 Sep 2017 than today.

http://bulletin.mercator-ocean.fr/en/PSY4#4/55.68/-64.29

The air temperatures (and rain) are also contributors. The international meteorological station at Ny-Ålesund, Svalbard has excellent long-term records, daily sondes, and rolling window records online.

Quote
What data do we have on water overturning that far north?  All I've seen recently are some tantalizing buoy data from much further south.
The oceanography of the entire area north of Svalbard to Severnaya Zemlya, including the two glacial troughs, has been intensively observed for decades, resulting in perhaps a hundred journal papers in the last seven years including a dozen from N-ICE2015. The 2018 below will help you build a comprehensive set of recent articles.

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017JC013198
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JC012424
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015JC010804
« Last Edit: April 04, 2018, 08:36:11 PM by A-Team »

uniquorn

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Re: The 2018 melting season
« Reply #232 on: April 04, 2018, 07:53:18 PM »
The Sea of Okhotsk was one of the big extent fallers yesterday.

Worldview today and Uni-Hamburg amsr2 Jan-Apr3

« Last Edit: April 04, 2018, 08:00:01 PM by uniquorn »

bbr2314

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Re: The 2018 melting season
« Reply #233 on: April 04, 2018, 08:14:05 PM »
The Sea of Okhotsk was one of the big extent fallers yesterday.

Worldview today and Uni-Hamburg amsr2 Jan-Apr3
As sea-ice becomes increasingly lop-sided into the mid-latitudes during winter, perhaps the melting of the excessive mid-latitude ice during spring results in even more latent heat release than normal -> much more 500MB blocking -> ultimately the high-Arctic ice gets hammered. As we are about to see in Beaufort/Chukchi as Bering's last dregs vanish before our eyes.

May 1, 2018, is going to yield satellite imagery substantially different for both ice cover (record lowest) and snowcover (possible record highest at least in terms of volume) than any other year in the satellite record.

Dharma Rupa

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Re: The 2018 melting season
« Reply #234 on: April 04, 2018, 08:24:28 PM »
May 1, 2018, is going to yield satellite imagery substantially different for both ice cover (record lowest) and snowcover (possible record highest at least in terms of volume) than any other year in the satellite record.

Interesting projection, though I have to ponder taking the bet on May 1 snow...Seems to me it is going to go really fast as the Winter cold lets up and allows southern air in.  We can watch the jet stream and see if it will keep the winter snows or flush them.

avaliablewrongdoer

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Re: The 2018 melting season
« Reply #235 on: April 04, 2018, 08:25:08 PM »
Hi new person here. Couple of quick questions.

1. When do scientists estimate the arctic will get it's first blue ocean event?

2. Any chance it will be ice free later this year? If yes around what time?

2. When the arctic is free of sea ice for the the first time what kind of global effects will it have on the weather?

<Edit Neven: I've copied your comment to a more appropriate thread.>
« Last Edit: April 04, 2018, 08:36:37 PM by Neven »

uniquorn

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Re: The 2018 melting season
« Reply #236 on: April 04, 2018, 08:27:53 PM »
Bering may hold out a little longer. The wind has changed again.

Daniel B.

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Re: The 2018 melting season
« Reply #237 on: April 04, 2018, 08:33:37 PM »
May 1, 2018, is going to yield satellite imagery substantially different for both ice cover (record lowest) and snowcover (possible record highest at least in terms of volume) than any other year in the satellite record.

Interesting projection, though I have to ponder taking the bet on May 1 snow...Seems to me it is going to go really fast as the Winter cold lets up and allows southern air in.  We can watch the jet stream and see if it will keep the winter snows or flush them.

I am with you.  Although the NA jet stream seems set in place for the next week or so, at this time of year, it will only take a day or two of warm southern winds (or rains) to wipe out much of the snow.  I question the record low also, as the current snow cover is likely to inhibit ice melt - at least for the rest of April.

A-Team

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Re: The 2018 melting season
« Reply #238 on: April 04, 2018, 08:41:53 PM »
Please don't post more nonsense on this forum about snow. Include a working url for your snow data and a thickness map and why you believe they are reliable or go to another forum.

bbr2314

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Re: The 2018 melting season
« Reply #239 on: April 04, 2018, 08:55:01 PM »
<snip, we're not going to do a repeat of last year, N.>
« Last Edit: April 04, 2018, 09:22:20 PM by Neven »

Lord M Vader

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Re: The 2018 melting season
« Reply #240 on: April 04, 2018, 09:15:02 PM »
Bbr2314: A-Team has posted tons of interesting posts that are very appreciated among many of us! I suggest that the snow get a separate thread in this forum as it is interesting to follow how the snowcover evolves.

uniquorn

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Re: The 2018 melting season
« Reply #241 on: April 04, 2018, 09:35:19 PM »
Beaufort Sea Mar29 from 2000-2018. (VIIRS only available for 2018)

Hopefully not too historic to be off topic. Some clouds but good enough for comparison

A-Team

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Re: The 2018 melting season
« Reply #242 on: April 04, 2018, 10:19:05 PM »
Yes and thanks for including the map and url that were missing from Reply #235 and the following unsupported (or just intuited) snow-casts from others.

It seems like a real struggle -- despite 1385 members -- to pool individual knowledge of internet resources and collect even the most basic information relevant to the 2018 melt season -- the assorted snow urls, the snow density urls, the melt pond urls, the albedo urls, the cloud urls, the water vapor advection urls, the sea surface temperature urls, the ice surface temperature urls, the radiative transfer urls, the rain urls, the lightning urls, the bottom melt urls, the top melt urls, the side melt urls. 

When multiple semi-independent sources exist, then we need to look at whether they more or less agree and if not, which is the most reliable (just as we do with all the ice thickness urls). Maybe none of them are helpful.

We are mostly not in a position to derive daily values ourselves for any of the above directly from raw satellite data. Less than 0.5% of the participants here look at netCDF data, the main storage medium for climate science (even though those are just a download and double-click in free Panoply). Some of the very best urls don't provide copy-paste graphics because it's assumed you will make your own.

On snow, we've heard a thousand times that it reflects sunlight, provides a thermal blanket, melts out to initiate ponding. True enough, but there's nothing here specific to the 2018 melt season, the same platitudes apply equally well to the 1918, 1818 and 1718 melt seasons.

Yes but how much solar was it reflecting yesterday? Is snow insulation materially affecting heat flow today? Will melt ponds surface tomorrow? How do these compare with the same dates in recent years? That is what it means to follow snow in the 2018 melt season.

From my end, the most interesting url (see up-forum) in the daily snow category provides both thickness and density maps, plus snow surface temperature and salinity. Snow thickness alone does not suffice to determine any of the above snow properties. Snow density etc are not the whole story either but they help. We know that from N-ICE2015 which had simultaneous field work, helicopter and satellite swaths.

I could see someone saying, 'yeah I've looked at all the data, read all the papers, it's all wrong, here's something better, here's data backing up that claim, here's what it means for the rest of 2018 melt season'.

I can't see the slightest interest in 'yeah I can't be bothered with data, journal papers are over my head, physics doesn't apply, it's all wrong anyway, I know all about Arctic Ocean snow from living here in New York, here's something far better, take my word for it: Sept 2025's gonna be all recovered/end of civilization.
« Last Edit: April 04, 2018, 10:36:38 PM by A-Team »

RoxTheGeologist

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Re: The 2018 melting season
« Reply #243 on: April 04, 2018, 10:24:57 PM »

 ...perhaps the melting of the excessive mid-latitude ice during spring results in even more latent heat release than normal...

Melting snow requires energy to melt, it isn't released. about 330 J/g if memory serves. A good rule of thumb is that breaking bonds requires energy. That's why ocean water temperature gets buffered at its melting point. If it didn't then when melt started it would be a run-away reaction.

bbr2314

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Re: The 2018 melting season
« Reply #244 on: April 04, 2018, 10:45:42 PM »

 ...perhaps the melting of the excessive mid-latitude ice during spring results in even more latent heat release than normal...

Melting snow requires energy to melt, it isn't released. about 330 J/g if memory serves. A good rule of thumb is that breaking bonds requires energy. That's why ocean water temperature gets buffered at its melting point. If it didn't then when melt started it would be a run-away reaction.

Sorry, I should have said melting/formation of ice, as both are occurring simultaneously in spring.

Niall Dollard

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Re: The 2018 melting season
« Reply #245 on: April 04, 2018, 10:56:58 PM »

I'm sure that's a first since I've been watching, and probably some millennia longer, (the year round blue water north of Svalbard).

Year round blue water ? I think we would have to wait until circa July 12th this year to confirm that. Maybe it will happen.

Ice though can arrive very late in the spring to the north coast of Spitzbergen (the largest island in Svalbard). Like last year it persisted right on the north coast through May and June. See pic attached for June 21st which shows very close drift ice (red area) right on the coast.

It wasn't until circa July 11th when the last finger of very close drift ice moved off from the NE coast of Sptizbergen. (second pic)

I will agree (as highlighted by A Team) that the area north of Sptizbergen devoid of ice is larger than usual this year. But it isn't unusual to see blue water north of Sptizbergen for today's calendar date (ie April 04). Looking back through the images available on Worldview back to 2012 approximate position of the main ice edge was as follows:

2012 - ice edge 80km north
2013 - 100km north
2014 - 50km north
2015 - 50km north
2016 - 100km north
2017 - ice edge on coast
2018 - 140km north

crandles

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Re: The 2018 melting season
« Reply #246 on: April 05, 2018, 12:03:34 AM »
« Last Edit: April 05, 2018, 12:14:22 AM by crandles »

uniquorn

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Re: The 2018 melting season
« Reply #247 on: April 05, 2018, 12:36:16 AM »
North of Svalbard 2017-06-25
Will have to wait a bit longer this year.

FishOutofWater

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Re: The 2018 melting season
« Reply #248 on: April 05, 2018, 06:32:51 AM »
NH snow cover is going to rapidly retreat over Asia over the next few weeks as well above normal temperatures melt it away. The sudden stratospheric warming pushed cold air out of the Arctic causing colder than normal temperatures over central and eastern North America, northern Europe and central Asia. That cold air is rapidly retreating over Asia and snow cover will retreat with it. Cool air and snow will stick around in central and eastern Canada while global snow cover makes a rapid retreat to well below normal by the beginning of May.

Spring is coming earlier to the largest continental masses as sloar energy, GHGs and water vapor team up to melt Eurasian snow and warm the atmosphere. The CFSv2 model may be exaggerating this effect some, but it's predicting what we're going to see this month.

In May, it is going to be warmer than normal in the CAA and Alaska melting the snow out earlier than normal. The CFS model isn't perfect but it's getting the climate trend we've been seeing for the past decade right.

The key to the CFS forecast as to what happens to sea ice for the next 3 months is high pressure over the Arctic ocean. That means greater than average solar energy hitting the ice.

NH snow extent at the end of March isn't indicative of NH summer conditions. Snow cover at the end of April and May is much more indicative. I see no evidence that last spring's heavy snow cover in late May will be repeated this year with the possible exception of eastern Canada.
« Last Edit: April 05, 2018, 09:50:20 PM by FishOutofWater »

litesong

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Re: The 2018 melting season
« Reply #249 on: April 05, 2018, 08:07:43 PM »
Melting snow requires energy to melt, it isn't released. about 330 J/g if memory serves. A good rule of thumb is that breaking bonds requires energy. That's why ocean water temperature gets buffered at its melting point. If it didn't then when melt started it would be a run-away reaction.
  That's why the North Pole acts as a weather attenuator...... at least for a while. From another thread:
Average Arctic sea ice VOLUME for April 1, for the period 1980-89, was ~ 30,200 cubic kilometers. April 1, 2018 Arctic sea ice VOLUME is ~ 21,900 cubic kilometers, ~ 8300 cubic kilometers LESS than the 1980-89 average for April 1. Through the course of the latter years, monthly Arctic sea ice volumes have ranged from  ~ 7000 to 12,000 cubic kilometers  below 1980's decade average, despite half a century of languid solar TSI energies, including 11+ years of low solar TSI(including a 3+ year period setting a 100 year record low).
////////
The energy needed to melt 8300 cubic kilometers of ice is......... ~ 25 to 26 times the annual energy consumption of the U.S. All this energy does NOT add temperature increase to the Arctic. Once ice-free conditions exist in the Arctic, any other added energy WILL raise Arctic water volume temperatures. About sixty times the volume of melted Arctic ice in the form of water will then be affected by any excess energy.
« Last Edit: April 05, 2018, 08:17:08 PM by litesong »