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D-Penguin

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Re: The 2020 melting season
« Reply #4250 on: July 31, 2020, 03:48:03 PM »
An update on the side by side comparison. Those apparent concentration drops are looking more real than not.
Slightly higher res version on twitter, for those without data limits: https://twitter.com/Icy_Samuel/status/1289080922617372672

(Large file, click to play)

Wow. The breakdown in the Beaufort is so clear.

The Crescent of low concentration right across the CAB, showing on the 27th and 28th in the sequence, has now disappeared but I await with interest to see if it re-appears as a significant factor as melting progresses and new weather systems impact the behavior of the CAB.

I just have a feeling that something 'different/significant' will happen to the ice of the CAB this season.

There are many quality and informed postings in this thread but for me this 'comparative graphic' and format combines the 'actuality' of what is happening to the Arctic ice and for that reason I am again  going with a +1
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Thawing Thunder

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Re: The 2020 melting season
« Reply #4251 on: July 31, 2020, 03:55:15 PM »
These two images from Aluminium and glennbuck combined show the dire state of the whole pacific side of the arctic: thin ice AND open water. That means accelerated melt by insolation, mechanical friction and more water circulation (hence less buffer effect of cold water surrounding the ice?). I suppose all that thin area will be gone in September. Maybe I should retract and consider a new low for 2020?
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Re: The 2020 melting season
« Reply #4252 on: July 31, 2020, 04:06:17 PM »
These two images from Aluminium and glennbuck combined show the dire state of the whole pacific side of the arctic: thin ice AND open water. That means accelerated melt by insolation, mechanical friction and more water circulation (hence less buffer effect of cold water surrounding the ice?). I suppose all that thin area will be gone in September. Maybe I should retract and consider a new low for 2020?

I think most of it will be gone by September but I do suspect we may have more Beaufort ice this year than some previous years but I doubt this will be enough to compensate the losses on the Atlantic/Siberian side of the basin.

Must be noted whilst that ice is diffused, it won't be a case of ice today gone tomorrow so to speak, it will take time but there is still more than enough time for that ice to melt. It will be interesting how it develops from here.

Pagophilus

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Re: The 2020 melting season
« Reply #4253 on: July 31, 2020, 04:13:17 PM »
These two images from Aluminium and glennbuck combined show the dire state of the whole pacific side of the arctic: thin ice AND open water. That means accelerated melt by insolation, mechanical friction and more water circulation (hence less buffer effect of cold water surrounding the ice?). I suppose all that thin area will be gone in September. Maybe I should retract and consider a new low for 2020?

Just to parse that out a bit, TT, perhaps more for my sake than yours  :) --

Insolation is fading rapidly now as a factor.
 
Mechanical friction will be pronounced if there are storms.
 
Bottom melt is becoming a dominant factor.  So, yes, more water circulation, especially any upwelling of warmer saline water, and less cold water buffering the ice are all coming more to the fore than ever now.  As is more contact with warmer waters when ice is blown into those warmer seas, which will/would have a massive effect on melting.

I was surprised by the strong effects of this storm.  If more storms arrive in August then who knows how low the ice could go.  It is very weather-dependent IMO, and that is hard to predict.
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Comradez

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Re: The 2020 melting season
« Reply #4254 on: July 31, 2020, 04:35:18 PM »
The ice in the Chukchi and Beaufort is now pre-conditioned to the same sort of honeycomb-like status that it was in by the start of August in 2012.  Now a second mega-cyclone in mid-August is all that would be needed to deliver the finishing blow to the ice there. 

wili

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Re: The 2020 melting season
« Reply #4255 on: July 31, 2020, 04:51:28 PM »
Paph wrote: "I was surprised by the strong effects of this storm."

Yes, besides spreading ice out into warmer waters and sometimes raining on ice, the wind in storms can stir water up from below that is saltier and warmer, it seems to me. Look up thread at the illustrations of 'sails' and 'keels' in ice floes.

When wind hits the 'sail' I have to assume it moves the much longer keel, and since these can be quite deep, it probably creates a stirring motion that I would think could effect fairly deep warm salty water, some of which probably comes up to the surface.

Can anyone confirm or show counter evidence for this pet theory of mine? I suppose samples of changes in temperature and salinity near these formations during high winds might be evidence? 
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bbr2315

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Re: The 2020 melting season
« Reply #4256 on: July 31, 2020, 05:03:12 PM »
The progression of Chukchi and Beaufort has been obscured by cloudcover on satellite. However, as today's Bremen and EOSDIS imagery confirm, both seas have for all intents and purposes now disintegrated.

The Laptev and Atlantic fronts have undergone a similarly deceptive evolution over the past week or so. As winds have changed direction, the pack has dispersed back into the open waters that have now accumulated insolation. Mixing is ongoing. On the surface the melt front has optically advanced somewhat, maybe a few 10s of KMs at most. But in reality, the melt front is now stretching hundreds if not thousands of KM WITHIN the pack and CAB itself. Within this region, the ice is now melting from above and below, and it is also slowly dispersing.

Concentration drops behind the respective Maginot Lines of the Laptev & ATL will become apparent very soon, and will follow the dissolution of the Beaufort and Chukchi. As I have been harping about for a week or three now, there is some chance the collapse of the Lincoln Sea could link up with the Laptev front and the ATL front could slough off thereafter. That does not mean the broken floes in between it and the rest of the pack will not refreeze in September, but there is some chance it falls off into the FRAM and the floes do not refreeze and we have a halocline overturning / destabilization event in the entire ATL east of the Lomonosov Ridge.

If the Atlantic hurricane season to date is any indication, I think we are going to see major hurricane(s) turn poleward in August and September, and that may lead to the obliteration of this component of the icepack.
« Last Edit: July 31, 2020, 05:30:41 PM by oren »

Bruce Steele

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Re: The 2020 melting season
« Reply #4257 on: July 31, 2020, 05:35:27 PM »
Wili, I recently saw a paper on keeling and it’s potential effect on the spin up of the Beaufort Gyre.
There were several other mechanisms, all physical, like open water area in leads, that complicate simple explanation however. But looking for evidence of mixing up into the surface waters of salinity from the halocline is rare in my recollections from many years watching the ITP bouys.
 But right now two buoys near the center of the gyre show a small ,but significant, increase in salinity on four different microcat sensors and on the ITP 114 salinity contours in the fresh water surface layer.
They also show a slight temperature drop at the 5 and 6 meter depths where the sensors reside.
So in my opinion, a reversal in direction of bouy drift and a speed up of surface transport both evidenced in the buoy data. Resulted in a mixing of the top 35-50 meters of surface water so the coldest water bathing the ice mixed down and the warmer waters mixed up and along with the water that mixed up some halocline waters also were mixed with surface waters.
 That I have never seen in all my years watching. Good evidence of salinity mixing up into surface waters. The reason we can see this salinity jump is due to the working microcat sensors on two buoys
in the right place at the right time. There are other working buoys in the Beaufort , with working microcat sensors that didn’t show a salinity jump. Maybe further from the storm or further from the center of the Gyre.
 So I can’t connect keeling with circulation of the surface layer, someday when there is no ice to keel and it’s all open water we get to see what a GAC can do for deep mixing without ice keels dragging the water around. High winds and in this case a reversal in direction of drift resulted in a small salinity
change at two buoy locations. A big deal in my buoy watching campaign but I don’t suppose it is really anything new, it’s just that the buoys were working well enough to show the signal. Or maybe it’s something new, I really don’t know.
 

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Re: The 2020 melting season
« Reply #4258 on: July 31, 2020, 07:10:47 PM »
2019 vs. 2020

Pagophilus

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Re: The 2020 melting season
« Reply #4259 on: July 31, 2020, 07:52:27 PM »
2019 vs. 2020
I was intrigued by how, on your gif, blumenkraft, the 2019 ice looked in a worse condition in some respects, particularly in looking more scattered and therefore more vulnerable. 

So I made a corresponding AMSR 2 gif, again 2019 vs 2020, July 30.  I am undecided -- any analysis needs more expertise than I possess.

Warning: Large(ish) gif.    Click to animate
« Last Edit: August 01, 2020, 01:50:10 AM by Pagophilus »
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wili

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Re: The 2020 melting season
« Reply #4260 on: July 31, 2020, 07:58:03 PM »
Thanks tons, Bruce. That makes a lot of sense
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Re: The 2020 melting season
« Reply #4261 on: July 31, 2020, 08:01:53 PM »
2019 vs. 2020
I was intrigued by how, on your gif, the 2019 ice looked in a worse condition is some respects, particularly in looking more scattered and therefore more vulnerable, blumenkraft. 


It is also important to note that according to the data from the neighboring topic, now the Аrea sea ice in the Central Arctic equaled the September 2019 minimum.

JNap

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Re: The 2020 melting season
« Reply #4262 on: July 31, 2020, 08:49:52 PM »
Weather Forecasts: The latest weather forecasts (July 31st, 12Z ) are now out for both ECM and GFS.    Both are in rough agreement over the next 4 days with the Low pressure centered over the CAA and the High pressure by Kara sea causing the winds to push ice out toward the warm Russian waters.

But by the time we get to day 6 (August 6th, 12Z) the ECM and GFS forecasts diverge in starkly opposite directions.

ECM: a strong Low pressure (984mb) is centered in the CAS.
https://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=nhem&pkg=z500_mslp&runtime=2020073112&fh=144

GFS:  a moderate High pressure (1020mb) is centered in the CAA/Beaufort
https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=z500_mslp&runtime=2020073112&fh=144

As is regularly stated on the Forum, we should be cautious with forecasts beyond 5 days.  But this degree divergence at day 6 is among the most that I remember seeing between ECM and GFS.   It seems that either situation (strong Low or a moderately strong High) would be bad for the ice. 

Time will tell if either forecast will be correct. 
« Last Edit: July 31, 2020, 09:28:18 PM by JNap »
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Freegrass

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Re: The 2020 melting season
« Reply #4263 on: July 31, 2020, 08:52:00 PM »
Latest Five Day Forecast
Wind @ Surface + Total Precipitable Water
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Frivolousz21

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Re: The 2020 melting season
« Reply #4264 on: July 31, 2020, 11:01:32 PM »
The ice in the Chukchi and Beaufort is now pre-conditioned to the same sort of honeycomb-like status that it was in by the start of August in 2012.  Now a second mega-cyclone in mid-August is all that would be needed to deliver the finishing blow to the ice there.

That would expedite things but it's gone regardless.

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Frivolousz21

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Re: The 2020 melting season
« Reply #4265 on: July 31, 2020, 11:03:12 PM »
The NW Passage ice has shattered completely in place and has started to disintegrate within that.

Probably  going to completely melt out.

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Frivolousz21

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Re: The 2020 melting season
« Reply #4266 on: July 31, 2020, 11:04:53 PM »
The most awful place to me is all along the FAR SOUTHERN CAB... MOD IS SHOWS THE THICKEST ICE HAS BEEN TOTALLY DECIMATED.

DON'T BE SURPRISED TO SEE MOST OF THE SOUTHERN CAB HAVE 1M OR THINNER ICE ON CRYOSAT  COME LATE SEPT/OCT
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weatherdude88

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Re: The 2020 melting season
« Reply #4267 on: July 31, 2020, 11:11:30 PM »
The ice in the Chukchi and Beaufort is now pre-conditioned to the same sort of honeycomb-like status that it was in by the start of August in 2012.  Now a second mega-cyclone in mid-August is all that would be needed to deliver the finishing blow to the ice there.

That would expedite things but it's gone regardless.

UH AMSR2 Beaufort sea ice area is looking robust, compared with previous years. 2020 Beaufort sea ice area is on pace to finish with the most sea ice area in the data set (post 2012).

Extrapolating the final area at minimum would be 200,000 square kilometers.



« Last Edit: July 31, 2020, 11:22:06 PM by weatherdude88 »

uniquorn

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Re: The 2020 melting season
« Reply #4268 on: July 31, 2020, 11:18:02 PM »
I get that, but can you actually see it? or measure it? I picked one floe that was easy. Normally we see 'goodbye waves' but I assume some other process happens in open water in the 'crack'.

edit: ok. It was easy to fine 'glue ice' melting too.
I keep wondering how much of that ice is still MYI, and how much is FYI. MYI ice melts away from the top, and refreezes at the bottom. So how much of that MYI is really still MYI, and not FYI that was added through winter?
PMFBI and stating the obvious - I wonder this too. You can't always eyeball the 90% below the waterline.
In recent years MYI has drifted down the Nares and been 'pulverised'. A process that I think I understand. So far this year ice in the Lincoln Sea melts 'in situ' while possibly drifting west. But there are no 'goodbye waves' which can be seen further south in the Parry channel.

@weatherdude88 some neighbouring arctic seas

Frivolousz21

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Re: The 2020 melting season
« Reply #4269 on: July 31, 2020, 11:21:40 PM »
The ice in the Chukchi and Beaufort is now pre-conditioned to the same sort of honeycomb-like status that it was in by the start of August in 2012.  Now a second mega-cyclone in mid-August is all that would be needed to deliver the finishing blow to the ice there.

That would expedite things but it's gone regardless.

UH AMSR2 Beaufort sea ice area is looking robust, compared with previous years. 2020 Beaufort sea ice area is on pace to finish with the most sea ice area in the data set (post 2012). Extrapolating the final area at minimum would be 200,000 square kilometers.



Its not all going to melt out

I'd go with 125,000km2 on that chart.

The thickest MYI along the Southern region by IIRC is the mcClure straight to the Parry channel will likely not melt out.

But two of the whoi bouys show bottom melt the last 40-50 days has taken place all the way to 75N along the border of the WCAB and Beaufort.

Only showing about 1.5CM of melt a day but that is only bottom  melt.

By Sept 1st about  75-100CM of bottom ice melt in the region will be enough to toast the fyi and some MYI.

My response was mostly that the flat grayish swiss cheese X1000 ice or the 35-60 percent Bremen  concentration ice the last 3 days I think is toast
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weatherdude88

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Re: The 2020 melting season
« Reply #4270 on: July 31, 2020, 11:33:51 PM »
The ice in the Chukchi and Beaufort is now pre-conditioned to the same sort of honeycomb-like status that it was in by the start of August in 2012.  Now a second mega-cyclone in mid-August is all that would be needed to deliver the finishing blow to the ice there.

That would expedite things but it's gone regardless.

UH AMSR2 Beaufort sea ice area is looking robust, compared with previous years. 2020 Beaufort sea ice area is on pace to finish with the most sea ice area in the data set (post 2012). Extrapolating the final area at minimum would be 200,000 square kilometers.



Its not all going to melt out

I'd go with 100,000km2 on that chart.

The thickest MYI along the Southern region by IIRC is the mcClure straight to the Parry channel will likely not melt out.

But two of the whoi bouys show bottom melt the last 40-50 days has taken place all the way to 75N along the border of the WCAB and Beaufort.

Only showing about 1.5CM of melt a day but that is only bottom  melt.

By Sept 1st about  75-100CM of bottom ice melt in the region will be enough to toast the fyi and some MYI

100,000 square kilometers would put 2020 well ahead of 2012,2015,2016, 2017, and 2019 at minimum for Beaufort sea ice area (6th place, post 2012 data set).

You are predicting a 6th place finish in the Beaufort, and 1st place finish for northern hemisphere sea ice area and extent?

There is no coincidence the lowest sea ice minimums had virtually no sea ice in the Beaufort.

Frivolousz21

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Re: The 2020 melting season
« Reply #4271 on: July 31, 2020, 11:36:49 PM »
Looking at the difference on these two AMSR2 graphics really show how bad this storm WRECKED the ice.

Just an amazing acceleration in ice deterioration in a few days thanks to near surface water overturning and rain.

The channel 89ghz grayscale shows a massive area that went from relatively stable to near melt out.

And a lot of this is still obscured by clouds.

The thickness/melt graphic shows how much wetter the remaining ice is and more open water
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Frivolousz21

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Re: The 2020 melting season
« Reply #4272 on: July 31, 2020, 11:40:49 PM »
The ice in the Chukchi and Beaufort is now pre-conditioned to the same sort of honeycomb-like status that it was in by the start of August in 2012.  Now a second mega-cyclone in mid-August is all that would be needed to deliver the finishing blow to the ice there.

That would expedite things but it's gone regardless.

UH AMSR2 Beaufort sea ice area is looking robust, compared with previous years. 2020 Beaufort sea ice area is on pace to finish with the most sea ice area in the data set (post 2012). Extrapolating the final area at minimum would be 200,000 square kilometers.



Its not all going to melt out

I'd go with 100,000km2 on that chart.

The thickest MYI along the Southern region by IIRC is the mcClure straight to the Parry channel will likely not melt out.

But two of the whoi bouys show bottom melt the last 40-50 days has taken place all the way to 75N along the border of the WCAB and Beaufort.

Only showing about 1.5CM of melt a day but that is only bottom  melt.

By Sept 1st about  75-100CM of bottom ice melt in the region will be enough to toast the fyi and some MYI

100,000 square kilometers would put 2020 well ahead of 2012,2015,2016, 2017, and 2019 at minimum for Beaufort sea ice area (6th place, post 2012 data set).

You are predicting a 6th place finish in the Beaufort, and 1st place finish for northern hemisphere sea ice area and extent?

There is no coincidence the lowest sea ice minimums had virtually no sea ice in the Beaufort.

And 100,000km2 is almost nothing.   

Its not likely that the Beaufort will have ice left and a new minimum happen.

We also have never seen the CAB get as much heat as it has this season.   Which is where it would be made up.

Regardless 100,000km2 is a drop in the bucket


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and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
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ArcticMelt2

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Re: The 2020 melting season
« Reply #4273 on: July 31, 2020, 11:41:43 PM »
There is no coincidence the lowest sea ice minimums had virtually no sea ice in the Beaufort.

It is important to consider that a violent storm has made a large breach in the Beaufort Gyre. This will provoke a sharp drop in concentration in the Beaufort Sea due to ice drift. The latitude is low there, so the melting will continue until mid-September.

VeganPeaceForAll

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Re: The 2020 melting season
« Reply #4274 on: July 31, 2020, 11:51:13 PM »
Edit. Last year's article.
Sorry someone shared that one in another group and I assumed it was current.
« Last Edit: August 01, 2020, 12:25:14 AM by VeganPeaceForAll »

Frivolousz21

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Re: The 2020 melting season
« Reply #4275 on: July 31, 2020, 11:53:30 PM »
Weather Forecasts: The latest weather forecasts (July 31st, 12Z ) are now out for both ECM and GFS.    Both are in rough agreement over the next 4 days with the Low pressure centered over the CAA and the High pressure by Kara sea causing the winds to push ice out toward the warm Russian waters.

But by the time we get to day 6 (August 6th, 12Z) the ECM and GFS forecasts diverge in starkly opposite directions.

ECM: a strong Low pressure (984mb) is centered in the CAS.
https://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=nhem&pkg=z500_mslp&runtime=2020073112&fh=144

GFS:  a moderate High pressure (1020mb) is centered in the CAA/Beaufort
https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=z500_mslp&runtime=2020073112&fh=144

As is regularly stated on the Forum, we should be cautious with forecasts beyond 5 days.  But this degree divergence at day 6 is among the most that I remember seeing between ECM and GFS.   It seems that either situation (strong Low or a moderately strong High) would be bad for the ice. 

Time will tell if either forecast will be correct.

The 12Z  GFS is pretty rough for the ice.

The euro phases some vorticity spokes into the small pv anomaly left from the storm  instead of taking it into the GIS pv.
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it go e-e-e-e-ow e-e-e-e-e-e-blaow

weatherdude88

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Re: The 2020 melting season
« Reply #4276 on: July 31, 2020, 11:55:05 PM »
Very informative article.
Europe's heat wave is about to bake the Arctic:
https://www.washingtonpost.com/weather/2019/07/26/europes-heat-wave-is-about-bake-arctic/?fbclid=IwAR19d1RoGkg0USJ4dpEJBuZo48g2BRg0SDmZipI1tEpllMEHkitULXaD7Rw

This is from 2019. The global weather models are forecasting weather favorable for sea ice retention.

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Re: The 2020 melting season
« Reply #4277 on: August 01, 2020, 12:10:09 AM »
The cyclone has caused divergence melt to slow down the extent loss, but the diverged ice will now melt quicker.
« Last Edit: August 01, 2020, 12:20:51 AM by glennbuck »

Michael Hauber

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Re: The 2020 melting season
« Reply #4278 on: August 01, 2020, 12:17:27 AM »
Comparison of Jaxa images shows the ice edge throughout the main Arctic basin is pretty much in the same place as it was 8 days ago when the slowdown started.

Area - NSIDC does continue to fall at a fast rate, but the area calculated by Wipneus in the homebrew thread from the higher resolution AMSR and Jaxa products has slowed and is now above 2019.

Models tending to show the cold slowly spreading and deepening across the Arctic although at least a couple runs try to push renewed ridging and heat in.  None suggest any substantial export of ice through the Altantic.

Comparison of ice in Beaufort/Chukchi region in MODIS visual to 2012 shows the ice is significantly healthier now after the storm than it was in 2012 prior to the storm.

Chances of 3rd or lower increasing.
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weatherdude88

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Re: The 2020 melting season
« Reply #4279 on: August 01, 2020, 12:37:25 AM »
higher resolution AMSR and Jaxa products has slowed and is now above 2019.

High resolution extent and area now greater than 2019 for the date.









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Re: The 2020 melting season
« Reply #4280 on: August 01, 2020, 02:02:29 AM »
higher resolution AMSR and Jaxa products has slowed and is now above 2019.

High resolution extent and area now greater than 2019 for the date.


Please note a single years(2019 25km) data was added to the 3.125 km data series. What you are saying is correct for the 3.125 data series and the anomalous plot can be ignored. A quick glance is deceptive and not everyone will spot it.

Paul

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Re: The 2020 melting season
« Reply #4281 on: August 01, 2020, 02:27:44 AM »
Forecasts are getting a little complicated now with quite a bit of disagreement. The ECM has on some runs potentially deepening the low(at the moment not as deep as the recent low) and heading it across the CAB, may bring colder uppers but no real benefit for the ice as cloud cover and too much wind would prevent temperatures dropping. The GFS in the medium term hints at a Beaufort high developing and potentially going down the route of a dipole. Not great either for the ice but as per ever, there will bound to changes from runn to run.

In the shorter term, the low we had over the Beaufort will continue it's journey towards Greenland, ejecting another shallow low which will head towards the Chukchi sea whilst high pressure dominates over the Laptev given potentially more compacting winds to the ice edge. In general the flow is preventing fram export but whilst the warmth is not as widespread over the Atlantic, it continues to be marginally above average, how this impacts the ice there remains to be seen. Inn general, for the next 3 to 4 days, the weather looks fairly unremarkable really.

Pagophilus

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Re: The 2020 melting season
« Reply #4282 on: August 01, 2020, 02:44:44 AM »
The latest from Worldview.  Beaufort to the Chukchi.  Yeah.  :o      The Swiss Cheesification of the ice in this area has indeed taken place up to 80N. Worse than it looks on AMSR2.   Click on image to enlarge. 

In case some of you are wondering what Swiss Cheesification is, I provide an image of an actual piece of Swiss cheese, with the thick end of the cheese wedge representing the ice north of 80N.

Obviously, all this recent melting is just ... the thin end of the wedge.   :P   ;)
« Last Edit: August 01, 2020, 07:22:39 AM by Pagophilus »
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pauldry600

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Re: The 2020 melting season
« Reply #4283 on: August 01, 2020, 02:54:14 AM »
A lot changes in a week. A week ago a record year looked very possible but now the slowdown and dispersion have made a top 3 place seem likely. Even the thin ice takes a while to melt and as nights get darker peak melting has passed now.

Still a lot of things happened in the Arctic in 2020 that never happened before so 2030 free of sea ice in Summer is very possible.

Every year the Arctic makes us think it is all going to melt out only to surprise us in another way. Slowdown is well under way now but there will be further big drops bringing final Jaxa extent to just under 4m like 2019 but let's wait and see.

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Re: The 2020 melting season
« Reply #4284 on: August 01, 2020, 04:59:42 AM »
2020 has no chance to finish above 2019.  August would have to be one of the coldest in the modern record.

It's very unlikely.  Melt momentum is way worse in 2020 because of the laws of physics.

It's what happens when your entire summer torches.

What did people expect to happen???  2020 to keep losing ice at breakneck speeds until the end??

Without a "slowdown" 2020 would have crushed even 2012 by a ton.  No one expects that because the science says that wasn't likely. That kind of energy just hasnt been available this summer or any summer so far.

2019 had a warm summer 2020 had an epic summer

But we all have different opinions that's the fun of it.





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Tigertown

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Re: The 2020 melting season
« Reply #4285 on: August 01, 2020, 05:08:31 AM »
Agree. We should not read too much into a few days of slowdown in apparent melt.
"....and the appointed time came for God to bring to ruin those ruining the earth." Revelation 11:18.

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Re: The 2020 melting season
« Reply #4286 on: August 01, 2020, 05:09:30 AM »
Looks like a polynya may open up at N78 W155.

D-Penguin

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Re: The 2020 melting season
« Reply #4287 on: August 01, 2020, 05:17:59 AM »
Agree. We should not read too much into a few days of slowdown in apparent melt.

Just a thought... Is it not more about compaction than slowdown in melt (apparent or actual)?
Remember...it's all about the Jet Stream you dummy...just a personal reminder!

D-Penguin

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Re: The 2020 melting season
« Reply #4288 on: August 01, 2020, 05:38:58 AM »
The warmth currently INVADING the CAB and CAA is nuts.

I AM VERY CONFIDENT THAT this summer we are going to see unprecedented open water in the CAB.

Record  low volume, extent, and area...

The only question I have is how low will it go?????

Posted by: Frivolousz21
« on: Today at 04:59:42 AM »Insert Quote

Without a "slowdown" 2020 would have crushed even 2012 by a ton.

Friv - You seem to have lost some confidence in your earlier conviction...any specific reason?
Remember...it's all about the Jet Stream you dummy...just a personal reminder!

ArcTickTock

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Re: The 2020 melting season
« Reply #4289 on: August 01, 2020, 05:40:33 AM »
CAA is melting out completely where I would not expect in July and just looks terrible.  Seems like the NW passage might be open for traffic in a week or so?

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Re: The 2020 melting season
« Reply #4290 on: August 01, 2020, 05:49:15 AM »
A lot changes in a week. A week ago a record year looked very possible but now the slowdown and dispersion have made a top 3 place seem likely. Even the thin ice takes a while to melt and as nights get darker peak melting has passed now.

Still a lot of things happened in the Arctic in 2020 that never happened before so 2030 free of sea ice in Summer is very possible.

Every year the Arctic makes us think it is all going to melt out only to surprise us in another way. Slowdown is well under way now but there will be further big drops bringing final Jaxa extent to just under 4m like 2019 but let's wait and see.

I was just thinking, "there are still 6 or 7 weeks left of melting, wonder how excited people can get based on one week of anticyclonic dispersion". Then I read the beginning of your comment, and thought, "here we go!" - but then I read the rest and was majorally mollified.

One week ago I escaped from a three-week Internet blackout only to see that I'd completely missed out on the July hammering. A new minimin seemed to be the generally accepted version of the future, anybody predicting anything else was quickly hammered down. Then a few days of blow from a short-lived cyclone and the previously repressed prognasticators rise to the surface, while even Friv seems to have lost steam.

I guess it is all part of the rich tapestry that is life. My two cents worth is that we will land in the middle of the fourth million, with a slim but real change of a new minimin. But what do I know?
because a thing is eloquently expressed it should not be taken to be as necessarily true
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Pagophilus

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Re: The 2020 melting season
« Reply #4291 on: August 01, 2020, 06:17:20 AM »
Agree. We should not read too much into a few days of slowdown in apparent melt.

Just a thought... Is it not more about compaction than slowdown in melt (apparent or actual)?

I agree.  If the icepack is in a 'compact' mass, sitting over the deeper water with its cold freshwater lens just beneath the ice, then the ice will be resistant to melting.  That (and I have been beating this drum for a while now) is currently the case.  The current low extent, which in this year's case just means that ice is so tightly gathered together, is rather misleading.

It is all about bottom melt now, and if the ice is not dispersed more into the surrounding warmer seas, then it is going to melt more slowly.  A couple of good storms, however, with widespread dispersal beyond the deeper basin, and we may be talking first or second worst summer extent. again. 
You may delay, but time will not.   Benjamin Franklin.

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Re: The 2020 melting season
« Reply #4292 on: August 01, 2020, 06:30:01 AM »
With a little more melt and the right weather the CAA can start bleeding out export above what is normal. A lot of things are still possible in the time left this season. Waiting on the next PIOMAS report.
P.S. In the above, I should have worded that "apparent slow down in melt." I put my words in the wrong order.
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Aluminium

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Re: The 2020 melting season
« Reply #4293 on: August 01, 2020, 07:02:21 AM »
July 1-31 (fast).

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Re: The 2020 melting season
« Reply #4294 on: August 01, 2020, 07:09:20 AM »
Latest Five Day Forecast
Wind + Temp @ Surface
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jdallen

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Re: The 2020 melting season
« Reply #4295 on: August 01, 2020, 08:20:14 AM »
I AM VERY CONFIDENT THAT this summer we are going to see unprecedented open water in the CAB.

Friv - You seem to have lost some confidence in your earlier conviction...any specific reason?
Just watch the area numbers.

They haven't slowed yet.

Mark me.

Until/unless they do, sharply, Friv's scenario is still in play.
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Telihod

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Re: The 2020 melting season
« Reply #4296 on: August 01, 2020, 08:23:46 AM »
It's funny how the cc deniers always come up with the one measure out of twenty that supports their argument that the ice isn't melting.
If there is a high pressure, then the ice isn't melting, it's compacting.
If there is a low pressure and the ice is spreading out: it's obvious that the ice isn't melting, because extent numbers aren't freefalling.

<Funny gif removed, can repost it in the freeform chatter thread. O>
« Last Edit: August 01, 2020, 09:37:57 AM by oren »

oren

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Re: The 2020 melting season
« Reply #4297 on: August 01, 2020, 10:05:47 AM »
In physical reality, what matters most is thickness distribution (and volume), then area, then extent. If the ice is driven in a compacting transport, extent will plummet with not much physical impact, while the reverse is also true under a divergence regime. What we can see unfortunately with the satellites and models is the opposite, extent in high accuracy, area in medium accuracy, thickness distribution and volume with low accuracy and delays.
This allows both parties to have numbers and data on their side, which is fine, just has to be interpreted according to physics and not just visible numbers on a chart.
The sunny July did huge damage to the CAB in terms of volume, and the open Siberian seas are a disaster waiting for imports, while the Atlantic front has huge amounts of open water as in 2012 and 2016, very unlike 2019. OTOH the Beaufort is full of ice and the CAA and Greenland Sea are still holding up. The question we do not know is how much of the remaining ice is in marginal conditions - still whole for now but will melt out by mid-Sept. This is what will dictate the area numbers, and partially the volume numbers as well, as volume calculation is tied to measured area changes. The extent numbers will be dictated by area numbers, but very highly affected by compaction or divergence - very visible, much less important IMHO. 2016 was almost as low as 2012 in terms of area, but very high up in terms of extent.
My take on things is that the ice is thinner than appears, due to the impact of July insolation and due to very high movements in the last few weeks, which induced faster bottom melt. I have never seen so many days where the CAB was entirely visible, and this while the ice was doing a crazy dance around the basin. Then came the cyclone with movements induced in the other direction. The CAA has been sweltering in heat and the ice is all broken up. So I expect a some point a lot of the ice which originated with a standard FYI thickness will melt out, and so will some of the thinner MYI. This will probably leave us with a total area record or near-record, even though the Beaufort may not be in record territory at all. Oh yeah, I also expect a volume record. I can't say the same for extent, which might be far away from 2012's record, though surely below 2019. This depends on random September factors so can beat the seasoned forecasters easily.
August is upon us, the answers will be clear in a few weeks time, not much longer to wait.

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Re: The 2020 melting season
« Reply #4298 on: August 01, 2020, 10:32:43 AM »
Beaufort Sea via RAMMB-SLIDER extremely fast playing to obscure the clouds.

Click to play. Trigger warning: Strobe effect!

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Re: The 2020 melting season
« Reply #4299 on: August 01, 2020, 12:27:56 PM »
Looking at JAXA and the ice after the Beaufort storm. 27th July image to 31st July image. The difference is stark. I know temperatures above water have dropped now. Just how much energy is still in the seas? If there is a lot stored up then I am very curious at how it will look in another 4 or 5 days. Looking at other members data inc. bouys etc. I am not convinced the ice in the Chukchi and Beaufort seas are going to fare well at all in early August.

Either way another future high to compact again or another storm will be brutal to extent numbers or volume drops. A dipole or high/low neighbouring system it looks bad. Ice on the move anywhere looks bad out of its current position in the central arctic basin. Only settled weak low/high pressure systems appear able to slow it down above water level, but again what energy is stored for bottom melt.

Again so many questions to a fairly beyond human capacity predictable situation of probable outcomes and events.