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Author Topic: Home brew AMSR2 extent & area calculation  (Read 982439 times)

A-Team

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Re: Home brew AMSR2 extent & area calculation
« Reply #2500 on: August 06, 2016, 02:39:48 PM »
Pansa linked to Modis dates on this situation over at:
http://forum.arctic-sea-ice.net/index.php/topic,1457.msg85629.html#msg85629

We can certainly see some atmospheric artifacts swirling around towards the end of the last 12 days ending August 5th. To resolve this, we would really need to get down to swath level to be sure the cloud overlay is synched to the swath tileage used to make daily product.

The real mystery to me, given three satellites in close succession shooting simultaneous bands at all these wavelengths all day long year after year, why people whose job it is to make these products have not used all the data to at least take out the grossest artifacts. From what JayW is posting, it looks like sub-daily products are feasible. That would be the place to start.

My sense overall is researchers are overly engaged with matlab and netCDF numerics, not rolling animations and using common sense. If the human eye can already see weather sweeping across, the answer is already known in advance, where/when/what problems are occurring. How hard can it be to pick off the low hanging fruit?

Especially now with reality-checking locally from Sentinel 1AB, launch dates 03 April 2014 and 25 April 2016. This particular event didn't have coverage with S1A; PolarPortal doesn't display 1B's at this time.
« Last Edit: August 06, 2016, 03:17:18 PM by A-Team »

Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2501 on: August 06, 2016, 03:39:35 PM »
A-Team, here a quick and dirty test. I took the images from day 8 to 12 from your GIF, created a mask of the extent of the 12th day and selected manually all the darkest areas of the anterior days back to day 8 (Only day 11 din't aport any useful areas). So this composite image from August 1st to August 5th might be one of the cleanest available - and though it's certainly not scientific, it might give some useful insight into the actual state of the ice.
« Last Edit: August 06, 2016, 03:51:39 PM by Thawing Thunder »

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2502 on: August 06, 2016, 05:19:36 PM »
Perhaps a comparison with Jaxa's sea ice concentration is useful. The bootstrap algorithm used by Jaxa is less sensitive to interference of water vapor and liquid water in cloud that interfere with the ASI algorithm used by Uni Hamburg.

Jaxa's data arrives a day later than the others, so the animation ends at 4 August.

Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2503 on: August 06, 2016, 05:50:33 PM »
The result looks quite similar to my photoshopped image. Now, what does that proof?  ;D

But seriously, this seems to be a good alternative. Is this graph somewhere inserted in a graph collection already? I use to visit www.seaice.de ...

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2504 on: August 06, 2016, 06:08:54 PM »
Is this graph somewhere inserted in a graph collection already? I use to visit www.seaice.de ...


No this is programmed from gridded data.

For ready made images look on the ADS?Nipr site:
https://ads.nipr.ac.jp/vishop/#/monitor

A-Team

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Re: Home brew AMSR2 extent & area calculation
« Reply #2505 on: August 06, 2016, 06:29:39 PM »
good alternative is this inserted in a collection already?
The easiest thing to do is go to their archive with an ftp client like Fetch, grab the desired date range for the 4 years available while at lunch, set up a separate folder for the LARGE format, sort by size to pull out the many preliminary, defective, blank and wrongly masked files (proving nobody there ever looks at them), open earliest image to be used in gimp, 'open as layers' the rest, set the crop dimensions, note your upper left crop corner coords (to match for other years), set your rolling mask, capture 'new layer from visible', discard all but these, done.

There are a lot of variations on this (some posted, some not) such as darken only, weighted averaging, 12321 vertical convolutions, ramped palette squeezing from both ends etc etc. Thinking of these time series as tall columns of single fixed geo-pixels (at the center of a 3x3 patch of neighboring pixels) on which unexpected outliers are identified to which some sort of correction operation is applied.

No doubt some of these would improve markedly on the original set by taking down water vapor effects -- which transit more rapidly than ice moves/thins/compacts -- if we had some way of measuring how each method was doing, say rms error from actual values (defined at much higher resolution from S1A values), we could say what was the best approach at various points in the season for various cloud conditions. A lot of quantitative cloud data is collected each day but analysis at these forums has mostly just been ternary (cloud/thin cloud/no cloud).

As mentioned, I am offline traveling next 2-3 weeks. Keep up the great work everyone!

ftp://ftp-projects.zmaw.de/seaice/AMSR2/3.125km/

A-Team

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Re: Home brew AMSR2 extent & area calculation
« Reply #2506 on: August 06, 2016, 06:36:00 PM »
No this is programmed from gridded data.
What does the palette consist of? [0,100] gray percentages? [0,255] on your own for percentages? Note if not dithered, all the frames have the identical palette and this is <255, meaning there is no degradation in using indexed color, meaning no loss in going to gif, meaning palette picking still works in every frame. As with the UHH AMSR2. (Though the tinting on their palette is flawed.)

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2507 on: August 06, 2016, 06:57:20 PM »
No this is programmed from gridded data.
What does the palette consist of? [0,100] gray percentages? [0,255] on your own for percentages? Note if not dithered, all the frames have the identical palette and this is <255, meaning there is no degradation in using indexed color, meaning no loss in going to gif, meaning palette picking still works in every frame. As with the UHH AMSR2. (Though the tinting on their palette is flawed.)

For the animations I increase the contrast somewhat (to see some detail in whites, more needed in winter than in summer) by a power scaling. In this case I calculate conc^0.7. So to go from concentration to the PNG compatible array:

[0,1]^0.7 -> [0,255]




Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2508 on: August 07, 2016, 01:24:48 PM »
2016 is still in the fast lane, competing with 2012 and 2015.

Update 20160806.

Extent: -93.7 (-277k vs 2015, -828k vs 2014, -688k vs 2013, +177k vs 2012)
Area: -171.9 (-187k vs 2015, -993k vs 2014, -847k vs 2013, -136k vs 2012)
 
You will find the updated graphs in the top post

The changes are now mostly in the CAB. CAB extent dropped -41k, second was CAA (-15k).
The area drop in the CAB was a huge -142k, ESS seconds with -30k.

The delta map shows the Arctic Basin and the reason for the big drops.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2509 on: August 07, 2016, 01:32:39 PM »
Animation of the Chukchi corner is another illustration of the exiting changes going on.

Tor Bejnar

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Re: Home brew AMSR2 extent & area calculation
« Reply #2510 on: August 07, 2016, 03:12:44 PM »
Animation of the Chukchi corner is another illustration of the exiting changes going on.
It appears that yesterday's cloud bank produced phantom ice (the one-day straight-line-edge-between-higher-and-lower-concentrations) - one day there, the next day 'poof'. 

Would I be correct to think the reported sea ice area decrease is partly due to this lost phantom ice?
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Nightvid Cole

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Re: Home brew AMSR2 extent & area calculation
« Reply #2511 on: August 07, 2016, 03:29:09 PM »
Animation of the Chukchi corner is another illustration of the exiting changes going on.
It appears that yesterday's cloud bank produced phantom ice (the one-day straight-line-edge-between-higher-and-lower-concentrations) - one day there, the next day 'poof'. 

Would I be correct to think the reported sea ice area decrease is partly due to this lost phantom ice?

If it comes from the 89 GHz AMSR2 data, yes. At such a high frequency, cloud interference is a large effect.

Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2512 on: August 07, 2016, 03:58:36 PM »
2016 is still in the fast lane, competing with 2012 and 2015.

Update 20160806.

Extent: -93.7 (-277k vs 2015, -828k vs 2014, -688k vs 2013, +177k vs 2012)
Area: -171.9 (-187k vs 2015, -993k vs 2014, -847k vs 2013, -136k vs 2012)
 
You will find the updated graphs in the top post

I think this weekend area and extend started to separate definitively from 2015 in your graphs. Compared in numbers, the extent difference with 2012 seems much bigger than it is, only looking at your graphs one can see the uptick in the 2012 curve that could lead to close the gap tomorrow or after tomorrow (if there doesn't occur weather that spreads the ice).

Neven

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Re: Home brew AMSR2 extent & area calculation
« Reply #2513 on: August 07, 2016, 04:43:37 PM »
Animation of the Chukchi corner is another illustration of the exiting changes going on.

It appears that yesterday's cloud bank produced phantom ice (the one-day straight-line-edge-between-higher-and-lower-concentrations) - one day there, the next day 'poof'. 

Would I be correct to think the reported sea ice area decrease is partly due to this lost phantom ice?


The same thing can be seen on the UB SIC map:



This is flash melting territory. It will blink on and off for a while to come I think.
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jdallen

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Re: Home brew AMSR2 extent & area calculation
« Reply #2514 on: August 07, 2016, 05:06:50 PM »
Bottom melt finally catching up with ice that ended the season about 1.85M thick
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helorime

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Re: Home brew AMSR2 extent & area calculation
« Reply #2515 on: August 07, 2016, 05:53:30 PM »
The question is, how much of this mobile, thin, shattered ice will melt out from bottom melt in the next few week.  Higher salt water is flowing in from the North Atlantic. Anomalous pockets of warmth still persist north of Canada.

I know that the HYCOM thickness maps are considered unreliable but still I suspect truth in this.  August 6 2012 vs 2016.  How much will go "poof"?
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Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2516 on: August 07, 2016, 06:04:06 PM »
My guess: Everything or at least the vast majority of the THIN ice south of the 80th parallel will go poof.

TerryM

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Re: Home brew AMSR2 extent & area calculation
« Reply #2517 on: August 07, 2016, 08:11:00 PM »
JayW


Hershel Island, shown in your animation, is at 18C & expecting a low of 12C, and no more rain until Thursday according to Weather Underground. Doesn't sound like aprex snow weather.


Terry

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Re: Home brew AMSR2 extent & area calculation
« Reply #2518 on: August 07, 2016, 11:18:40 PM »
Wipneus, do you still reckon Jaxa 10km is the one to follow when UH 3km spikes down away from the rather more gradual Jaxa drop? (UH is about 300k below in the CAB after the latest spike)


Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2519 on: August 08, 2016, 08:58:40 AM »
Wipneus, do you still reckon Jaxa 10km is the one to follow when UH 3km spikes down away from the rather more gradual Jaxa drop? (UH is about 300k below in the CAB after the latest spike)

For area yes, here the resolution is not so important. Extent is another matter, UH's 3.125km resolution will resolve much more of the open water within the ice pack and is expected to yield a smaller number.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2520 on: August 08, 2016, 12:34:37 PM »
Small extent drop and even an uptick for area, just a temporary hiccup?

Update 20160807.

Extent: -27.7 (-223k vs 2015, -798k vs 2014, -635k vs 2013, +97k vs 2012)
Area: +20.7 (-126k vs 2015, -844k vs 2014, -825k vs 2013, -106k vs 2012)
 
You will find the updated graphs in the top post

Most regions had only small extent changes except CAA with -26k.

Area of the CAB had a sort of rebound after yesterday's drop and increased by +53k. The CAA went on downwards: -32k.

Attached is a regional delta map of the Laptev section. We can see the last obstacle in the North (Eastern) Passage is in the Laptev Sea. The polynyas in the pack near the New Siberian Islands seem to have developed in a "bite".
 

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2521 on: August 08, 2016, 12:45:00 PM »
For the animation I update the one created from Jaxa's sea ice concentration data which now runs to 6 August. Note the absence of the discussed high concentration blip visible in Uni Hamburg and Uni Bremen maps.
 

JimboOmega

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Re: Home brew AMSR2 extent & area calculation
« Reply #2522 on: August 08, 2016, 06:19:15 PM »
Small extent drop and even an uptick for area, just a temporary hiccup?

Update 20160807.

Extent: -27.7 (-223k vs 2015, -798k vs 2014, -635k vs 2013, +97k vs 2012)
Area: +20.7 (-126k vs 2015, -844k vs 2014, -825k vs 2013, -106k vs 2012)
 
You will find the updated graphs in the top post

Most regions had only small extent changes except CAA with -26k.

Area of the CAB had a sort of rebound after yesterday's drop and increased by +53k. The CAA went on downwards: -32k.

Attached is a regional delta map of the Laptev section. We can see the last obstacle in the North (Eastern) Passage is in the Laptev Sea. The polynyas in the pack near the New Siberian Islands seem to have developed in a "bite".

Very visible in the delta map is a lot of coastal "noise".  Does this matter to the numbers in any significant way? Or does it add up to a small fraction of a km^2?

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2523 on: August 08, 2016, 06:59:34 PM »

Very visible in the delta map is a lot of coastal "noise".  Does this matter to the numbers in any significant way? Or does it add up to a small fraction of a km^2?

In my calculations most or all of that coastal noise is filtered before the ice is accounted (in the images you are looking at the raw sea ice concentration data received from Uni Hamburg).

That is not true for the NSIDC and CT-area numbers that I report in another thread. I call those "shadow data", repeating their calculations as exact as possible.

Also in Jaxa calculations (which appear in some graphs) there is no coastal ice filtering. In Jaxa's case it is not needed, they apply an effective filtering themselves as you can see in the above animation.

weatherdude88

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Re: Home brew AMSR2 extent & area calculation
« Reply #2524 on: August 09, 2016, 03:33:40 AM »
The question is, how much of this mobile, thin, shattered ice will melt out from bottom melt in the next few week.  Higher salt water is flowing in from the North Atlantic. Anomalous pockets of warmth still persist north of Canada.

I know that the HYCOM thickness maps are considered unreliable but still I suspect truth in this.  August 6 2012 vs 2016.  How much will go "poof"?


DMI sea ice thickness 2012 VS. 2016




slow wing

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Re: Home brew AMSR2 extent & area calculation
« Reply #2525 on: August 09, 2016, 04:47:15 AM »
Striking difference there, weatherdude88. Are they supposed to be directly comparable?

Looks like ~8000 km3 in 2016 but only ~5000 km3 in 2012.

Not sure I am immediately convinced by 2012's sub-1m thick ice over large areas and almost all the way in to the North Pole, nor by all the 1.5-2.5m thick ice still supposed to be in front of the Bering Strait now.

For comparison for this year, I repost below the actual measured thickness on various dates over April 2016. Would the Pacific-side ice be expected to be thicker in many places now, i.e. on 7 August, than it was in April?

A detail but is the colour palette the same or is there more dark blue around 1m thick for 2012 compared to 2016?
« Last Edit: August 09, 2016, 05:02:56 AM by slow wing »

slow wing

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Re: Home brew AMSR2 extent & area calculation
« Reply #2526 on: August 09, 2016, 05:19:50 AM »
Below is a comparison between U. Bremen's sea ice concentration maps for 7 August 2012 and 8 August 2016 (sorry for 1 day mis-match).

For 2012, the U. Bremen map shows solid looking ice over most of that region where the DMI thickness prediction posted above was for sub-1m.

Conversely, the ice in front of the Bering Strait - purportedly 1-5-2.5m thick now in most places according to the DMI map posted above - looks quite ill in the 8 August 2016 U. Bremen map.
« Last Edit: August 09, 2016, 05:25:07 AM by slow wing »

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2527 on: August 09, 2016, 04:49:07 PM »
Update 20160808.

Extent: -71.6 (-230k vs 2015, -766k vs 2014, -571k vs 2013, +233k vs 2012)
Area: -102.9 (-218k vs 2015, -886k vs 2014, -674k vs 2013, +17k vs 2012)
 
You will find the updated graphs in the top post

Regional extent dropped in the CAA (-32k) and the CAB (-29k).

The regions dropping most in area where CAACAB (-59k), ESS (-29k) and CAA (-23k).

Delta map of the Beaufort-Chukchi-ESS corner attached.
« Last Edit: August 09, 2016, 05:32:53 PM by Wipneus »

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2528 on: August 09, 2016, 04:55:41 PM »
The southern branches of the NW passage are open again (as far as the UH AMSR2 sea ice concentration data can tell). The main passages may be passable soon as well.

seaice.de

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Re: Home brew AMSR2 extent & area calculation
« Reply #2529 on: August 09, 2016, 04:58:33 PM »
Yesterday, August 8, was still some drift ice that was not picked up with AMSR2.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2530 on: August 10, 2016, 04:22:52 PM »
Declines are too small to keep up with 2012, which will continue to drop unabated for the next few days.

Update 20160809.

Extent: -25.9 (-226k vs 2015, -723k vs 2014, -535k vs 2013, +249k vs 2012)
Area: -15.1 (-261k vs 2015, -812k vs 2014, -614k vs 2013, +159k vs 2012)
 
You will find the updated graphs in the top post

CAB extent dropped -17k. No other regional extent dropped remarkable, neither did any of the regional area's.

Attached is the delta map of the Canadian Archipelago. Reds and blues are in balance (net extent drop -3.8k ). Outside the islands the ice from the pack can be seen retreating away from the Beaufort.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2531 on: August 10, 2016, 04:34:32 PM »
Animation of the Arctic Basin. Despite the slow declines today low concentration ice is still approaching the Pole.
 
« Last Edit: August 11, 2016, 09:10:07 AM by Wipneus »

Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2532 on: August 10, 2016, 04:51:24 PM »
How does it come, that with so much remarkably thin and dispersed ice the melt came to such an abrupt halt? I expected longer melt under these conditions. Or is the sun already too weak?

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2533 on: August 10, 2016, 07:06:02 PM »
How does it come, that with so much remarkably thin and dispersed ice the melt came to such an abrupt halt? I expected longer melt under these conditions. Or is the sun already too weak?

As you can see from the graphs, the ride is never without bumps. There are many reasons for this; the measurements are not perfect; compaction and dispersion (caused by winds and currents)  decrease (increase) extent. Ice concentrations near 15% can suddenly (dis)appear from the accounting.
And yes, sun is weaker, warm winds from the continents is not so warm anymore. It all results in temperatures close to freezing point and more and more the ice surface freezes which results in higher measured concentrations.

slow wing

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Re: Home brew AMSR2 extent & area calculation
« Reply #2534 on: August 11, 2016, 01:34:00 AM »
Animation of the Arctic Basin. Despite the slow declines today low concentration ice is still approaching the Pole.
Thanks for all these wonderful graphics, Wipneus. Is this gif all there? I only get a ~100kB file with one image.

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Re: Home brew AMSR2 extent & area calculation
« Reply #2535 on: August 11, 2016, 04:47:03 AM »
Same here, no animation.

Some +3°C here this morning with colder temps sloshing down on Scandinavia, I'm not even at 60°N. If something more exciting should happen up there it will probably be next week.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2536 on: August 11, 2016, 09:13:09 AM »
Animation of the Arctic Basin. Despite the slow declines today low concentration ice is still approaching the Pole.
Thanks for all these wonderful graphics, Wipneus. Is this gif all there? I only get a ~100kB file with one image.

Sorry about that, the forum software is picky, or rather buggy, about what gifs to accept and what to only take a single frame. I did cut off two pixels from the top and now it loads.

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Re: Home brew AMSR2 extent & area calculation
« Reply #2537 on: August 11, 2016, 01:56:38 PM »
Some artifacts are visible in the SIC map over the CAA, I suspect that this increases extent by about +20k, area much less.

So with the warning that the numbers may be revised, probably downwards:

Update 20160810.

Extent: -80.6 (-234k vs 2015, -730k vs 2014, -560k vs 2013, +297k vs 2012)
Area: -33.3 (-247k vs 2015, -824k vs 2014, -571k vs 2013, +249k vs 2012)
 
You will find the updated graphs in the top post

Most of the extent decline is in the Chukchi (-31k) and CAB (-30k) regions.

The area declines are from the same regions CAB (-40k) and Chukchi (-22k). The ESS area increased by +35k.

The delta map is the Beaufort-Chukchi-ESS corner. It is where most of the extent and area changes are.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2538 on: August 11, 2016, 02:00:13 PM »
An animation of the Greenland Sea region. Some ice is actually passing the Fram Strait. It does not come far.

2phil4u

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Re: Home brew AMSR2 extent & area calculation
« Reply #2539 on: August 11, 2016, 07:22:43 PM »
Is it possible that we see a pretty high minimum but then a slow refreeze cause of the high sst ?
GFS proggs cold temperatures over the cab and at sibirean side, also europe should not come to much closer to the pole with iceloss.
The parts of the cab with low cocentrations could easily eliminated by other regions with refreezing yet and the drift.
It is possible that we see a year like 2015 ?

Archimid

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Re: Home brew AMSR2 extent & area calculation
« Reply #2540 on: August 11, 2016, 07:35:24 PM »
I see a lot of  plus and minuses. I wonder how is that variation compared to other melting seasons. The ice being in seemingly weaker conditions I would expect the daily area variation to vary more in years like this. How much more would be interesting.
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Re: Home brew AMSR2 extent & area calculation
« Reply #2541 on: August 12, 2016, 06:23:47 PM »
Not surprisingly, 2016 cannot keep up with the rates that 2012 could maintain. It is still ahead of 2015.

Update 20160811.

Extent: -18.5 (-125k vs 2015, -640k vs 2014, -513k vs 2013, +515k vs 2012)
Area: +37.0 (-53k vs 2015, -741k vs 2014, -499k vs 2013, +371k vs 2012)
 
You will find the updated graphs in the top post

Regional extent changes of CAB (+20k) and Laptev (-20k) are the only worth mentioning.

Area increased in the CAB (+39k) and CAA (+20k). The area in the ESS declined -30k.

The delta map is from the Laptev section. The ice is still melting in this region, whether the NE passage will open de[ends more on the movements of the ice in the ice pack.
The New Siberian Islands Bite keeps growing slowly.
 

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Re: Home brew AMSR2 extent & area calculation
« Reply #2542 on: August 12, 2016, 06:26:39 PM »
To continue with the question about the NE passage, if the ice pack keeps moving this way it may open soon as the animation shows.

Needs a click to start.

Neven

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Re: Home brew AMSR2 extent & area calculation
« Reply #2543 on: August 12, 2016, 09:56:37 PM »
With that storm kicking in two days from now, I expect the NSR to be fully open next week.
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Re: Home brew AMSR2 extent & area calculation
« Reply #2544 on: August 13, 2016, 10:22:01 AM »
With that storm kicking in two days from now, I expect the NSR to be fully open next week.


The crew (and support team) of the Northabout will certainly be pleased to see some dispersal of the ice on the eastern flanks of the Taymyr Peninsula. For the last 36 hours or so, they've been more or less stuck near a longish spit of land, thus prevented from moving further by that stubborn stretch of 9-10 ice near the coast in the western reaches of the Laptev.

http://polarocean.co.uk/tracking/

Their (currently) most recent ship's log entry is titled... "We must have tried every single option three times. Just 3 miles, but it could have been 300 miles."

http://polarocean.co.uk/must-tried-every-single-option-three-times-just-3-miles-300-miles/

As mentioned elsewhere, on his GWC blog, Jim Hunt has a few articles about this attempt to traverse both the NSR and the NWP in a 15-metre yacht in a single season.

http://greatwhitecon.info/2016/07/northabouts-great-adventure/#comment-215187

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2545 on: August 13, 2016, 05:10:53 PM »
No data from Uni Hamburg received yet. Here is an update of the Jaxa AMSR2 sea ice concentration animation.

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Re: Home brew AMSR2 extent & area calculation
« Reply #2546 on: August 13, 2016, 06:01:43 PM »
Amazing to see how the big block, despite disintegrating, can result in a persistent patch of sea ice in an otherwise clear Beaufort.

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Re: Home brew AMSR2 extent & area calculation
« Reply #2547 on: August 16, 2016, 10:19:35 AM »
Still no update from Hamburg. There probably would have been enough to discuss.

So I attach the Jaxa animation, now updated to 14th August. It shows the damage done to the remaining ice in Laptev and the CAB loosing ice from the inside. Big extent losses not there yet, but in the last frame area lost -155k.

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Re: Home brew AMSR2 extent & area calculation
« Reply #2548 on: August 16, 2016, 11:39:28 AM »
Wipneus,

Thank you for these great updates.

It's fascinating to see the two upwelling "holes" in the pack developing over the Mendeleev Ridge.

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Re: Home brew AMSR2 extent & area calculation
« Reply #2549 on: August 16, 2016, 02:40:11 PM »
From that animation, you can see the disturbing impacts of this cyclone on the Atlantic side. Ice is moving towards the Barents between Svalbard and Franz Josef and it is melting as it hits the warm waters. Also looks like export through the Fram just got going. No ice moving this direction will last  long.