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Pagophilus

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Re: 2019 sea ice area and extent data
« Reply #1300 on: June 24, 2019, 06:33:02 AM »

Pragma, thank you.  But all the credit has to go to the NSIDC, they can be obtained here:

http://nsidc.org/arcticseaicenews/sea-ice-comparison-tool/

I think they are amazing too, and I am glad to bring them before this forum if they have not previously around.

LOL! I'm laughing and embarrassed. As I have mentioned before, NSIDC is updating their tools all the time and are very receptive to suggestions.

I was going to email them, suggesting a comparison tool.  :-[

Um, er ... never mind  :)

Not at all -- it was a completely natural mistake -- although if you knew how limited my programming skills are you would not have made it.   I myself just stumbled upon these comparison maps.  I had never seen anyone use them here, so I felt like someone pulling out a clamshell phone at an Apple convention, until you kindly responded. 

binntho

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Re: 2019 sea ice area and extent data
« Reply #1301 on: June 24, 2019, 07:28:19 AM »
Like many another, I have been wondering why extent losses have dropped so slowly.  I think much of the reason may lie in the Barentz Sea.  Two tongues of ice have been projecting into the Barentz for some time, as the ice pack rotated away from the Pacific side and towards the Atlantic side, an unusual move.  One tongue projects between Svalbard and FJL and one between FJL and SZ.

The initial reaction was that this ice had gone to 'oblivion', into the 'killing zone', and I too was of that opinion.  In fact the ice tongues have been remarkably persistent (see the first comparative NSIDC map below, comparing June 8 and 22 this year). 

June has been quite cloudy over those two tongues so estimating drift speed of the ice is a bit tricky, but a recognizable structure in the esternmost tongue seems to drift 40 km between June 12th and June 21st. In the westernmost tongue, a recognizable structure drifts some 100 km between the two days.

So the ice in those tongues is drifting southwards, but the tongues themselves are not growing, hence a lot of melting melting is happening (as expected). The tongues themselves also show a lot of internal melting, i.e. the ice is becoming more dispersed and "sludge" like, with thin melting streamers even inside the tongues themselves.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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Re: 2019 sea ice area and extent data
« Reply #1302 on: June 24, 2019, 07:43:27 AM »
It is reasonable, to remark when statements in in other threads , e.g. "Panzer divisions" (not my phrase) fail to mobilise and Friv's extravagant forecasts do not materialise in or seem justified by changes in the area and extent data so far. "Looks like it's going to [be] pretty soon that sailing from Pacific to Atlantic w/o an ice breaker. Perhaps June."(NOT one of Frivs)  is a candidate for the future.

In defense of Friv, I would say that the recent loss of  > 1m km2 of area in a week was an example of very high melt which he had foreshadowed prior to it's occurrence.

In defense of myself as the person who made the comment about the open water from the Pacific to Atlantic.  I would ask you to look at the northern sea route and ask you if there is any segment which you obviously think is going to survive beyond June?

Lotta folks here complaining about this thread being derailed by non-data, but that starts with you.

If you want to express your contempt of what I am posting on the melting thread, it would be nice if you could post your criticism there so I can reply and the readers of the extent and data thread don't have to read the discussion.

<I agree that if Gerontocrat wants to remark on other people's remarks, it's better to do it where the remarks were made, but this is the last of the meta-discussion I'm going to allow here. Gerontocrat can have the last word if he wants; N.>
« Last Edit: June 24, 2019, 08:38:44 AM by Neven »

Neven

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Re: 2019 sea ice area and extent data
« Reply #1303 on: June 24, 2019, 08:03:45 AM »
These are excellent maps. Thanks for taking the time, and I hope they become a regular feature on this thread.

Agreed, but they fit even better in the melting season thread.
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weatherdude88

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Re: 2019 sea ice area and extent data
« Reply #1304 on: June 24, 2019, 01:58:28 PM »
Looking at the raw daily data, 2019 NSIDC sea ice area is now the fifth lowest value in the data set. For 6.23, the daily value is 7,787,023 kilometers squared. There was a loss of 102,855 kilometers squared from the previous date.

2019 now has 236,390 kilometers squared more than 2012, 32,029 kilometers squared more than 2010, 9,356 kilometers squared more than 2007, and 8,144 more than 2016.

edit: gerontocrat was able to answer my question on the Central Arctic sea disparity for the sub 2008 data set. For my posts on 2007 sea ice area, I should of been adding 310,000 kilometers squared to the final value when all seas had been added for the pole hole adjustment.
« Last Edit: June 25, 2019, 03:18:34 AM by weatherdude88 »

weatherdude88

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Re: 2019 sea ice area and extent data
« Reply #1305 on: June 24, 2019, 02:09:53 PM »
UH AMSR2 data is showing more high latitude sea ice extent and area in the arctic basin, than the highest melt years.


UH AMSR2 CAB extent


UH AMSR2 CAB area
« Last Edit: June 24, 2019, 04:36:57 PM by weatherdude88 »

Pagophilus

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Re: 2019 sea ice area and extent data
« Reply #1306 on: June 24, 2019, 04:33:11 PM »
Like many another, I have been wondering why extent losses have dropped so slowly.  I think much of the reason may lie in the Barentz Sea.  Two tongues of ice have been projecting into the Barentz for some time, as the ice pack rotated away from the Pacific side and towards the Atlantic side, an unusual move.  One tongue projects between Svalbard and FJL and one between FJL and SZ.

The initial reaction was that this ice had gone to 'oblivion', into the 'killing zone', and I too was of that opinion.  In fact the ice tongues have been remarkably persistent (see the first comparative NSIDC map below, comparing June 8 and 22 this year). 

June has been quite cloudy over those two tongues so estimating drift speed of the ice is a bit tricky, but a recognizable structure in the esternmost tongue seems to drift 40 km between June 12th and June 21st. In the westernmost tongue, a recognizable structure drifts some 100 km between the two days.

So the ice in those tongues is drifting southwards, but the tongues themselves are not growing, hence a lot of melting melting is happening (as expected). The tongues themselves also show a lot of internal melting, i.e. the ice is becoming more dispersed and "sludge" like, with thin melting streamers even inside the tongues themselves.

I agree wholeheartedly.  For the Arctic overall, this export of ice to the Barentz involves net loss of ice, period.  However, I think the ice is melting slower than one might expect, because so much ice has entered the Barentz, chilling the top layer of (now fresher) water.   Your observation that the Barentz has been cloudy over the past few weeks is another factor, I think, in reducing the rate of melting.

This Barentz sea ice will melt out (maybe soon, but the tongues are persistent) and there will be less ice in the CAB, so the medium and longer term prospects for the ice are troubling.


Pagophilus

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Re: 2019 sea ice area and extent data
« Reply #1307 on: June 24, 2019, 04:35:46 PM »
These are excellent maps. Thanks for taking the time, and I hope they become a regular feature on this thread.

Agreed, but they fit even better in the melting season thread.

Done!

Pragma

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Re: 2019 sea ice area and extent data
« Reply #1308 on: June 24, 2019, 05:39:32 PM »
These are excellent maps. Thanks for taking the time, and I hope they become a regular feature on this thread.

Agreed, but they fit even better in the melting season thread.

As they are of comparative extent data, I'm curious why you think so.

Not a  big deal, but I can see equally why they could be in either.

I ask because I post in threads and then second guess myself as to whether it is OT or not.

OT drift is easy, and usually unintentional.

cognitivebias2

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Re: 2019 sea ice area and extent data
« Reply #1309 on: June 24, 2019, 05:44:38 PM »
UH AMSR2 data is showing more high latitude sea ice extent and area in the arctic basin, than the highest melt years.

...

dude,
  Can you give us the correlation between CAB area/extent now and at minimum? 

I just ask because, as counterpoints go, this one feels a bit strained.

Neven

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Re: 2019 sea ice area and extent data
« Reply #1310 on: June 24, 2019, 07:41:32 PM »
As they are of comparative extent data, I'm curious why you think so.

Because graphs are a better representation of data than maps, but maps are a better visual representation of what goes on where during the melting season. Sometimes the threads overlap, but on the whole, I feel like this is the thread for graphs and maps go into the melting season thread.
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Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #1311 on: June 24, 2019, 07:43:10 PM »
too much meta discussion...

forkyfork

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Re: 2019 sea ice area and extent data
« Reply #1312 on: June 24, 2019, 08:32:04 PM »
UH AMSR2 data is showing more high latitude sea ice extent and area in the arctic basin, than the highest melt years.

...

dude,
  Can you give us the correlation between CAB area/extent now and at minimum? 

I just ask because, as counterpoints go, this one feels a bit strained.
i see years with higher area/extent than now which had a low minimum as well as vice versa

b_lumenkraft

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Re: 2019 sea ice area and extent data
« Reply #1313 on: June 24, 2019, 08:39:38 PM »
too much meta discussion...

+1

Please take the discussions about the data to the melting thread. This is the thread for the data. This is not for discussions about the data.

be cause

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Re: 2019 sea ice area and extent data
« Reply #1314 on: June 24, 2019, 09:44:03 PM »
I'm beginning to think that the unnecessary abuse of Gerontocrat and this thread has relieved us of one of our most valuable posters . b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1315 on: June 25, 2019, 05:43:32 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
June 24rd, 2019:
     9,597,909 km2, a drop of -60,652 km2.
     2019 is now 6th lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

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

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1316 on: June 25, 2019, 09:13:56 AM »
JAXA ARCTIC EXTENT :-  9,597,909 km2(June 24, 2019)

- Extent is 5th 6th lowest in the satellite record.
- Extent loss on this day 61 k, 16 k less than the average loss on this day of 77 k.
- Extent loss from maximum 4,673 k, 134 k (3.0 %) greater than the average of 4,539 k loss from maximum by this day,
- On average 45.9% of the melting season done, with 81 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.26 million km2, 4th lowest in the satellite record, and 1.08 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt gives a result of 4.36 million km2, 6th lowest, and 1.18 million km2 above 2012.

Other Stuff

Until the weekend GFS showing  temperature anomalies at +0.9 to +1.9 degrees celsius. During this time the images suggest high +ve anomalies in central and eastern Siberia, with contrasting and sometimes strong -ve anomalies for most of the time on land and coastal sea by and in the Beaufort/CAA and Western Siberia, and in contrast again mostly +ve anomaly over most of the Arctic Ocean.

Over the weekend the picture changes somewhat. By Monday the CAA gets warmer, NW Canada and Alaska get a lot colder, and on the Russian side warmth moves west into areas bordering the Laptev and Kara, while the ESS area switches from strong warmth to a cold snap. However, over the Arctic Ocean itself there is a modest +ve  temp anomaly. Overall the Arctic temp anomaly stays well below 1 degree celsius.

A complicated picture.

We are now entering the period of maximum daily extent loss that lasts until mid or late July and then very gradually declines.
Apart from 2 days, over the last 3 weeks and more extent loss has been below or well below average.
_____________________________________________________________________
The volume data for June should be available by late next week. It will be interesting to see what has happened to volume and perhaps more importantly, thickness during this month.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1317 on: June 25, 2019, 02:06:20 PM »
NSIDC Total Area as at 24 June 2019 (5 day trailing average) 7,698,353  km2
                        
Total Area         
 7,698,353    km2      
-265,666    km2   <   2010's average.
-312,713    k   <   2018
-890,044    k   <   2000's average.
         
Total Area Change   -118    k   loss
Peripheral Seas   -28    k   loss
Central Seas__   -63    k   loss
Other Seas___   -26    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -9    k   loss
Greenland____   -20    k   loss
Barents ______    0    k   gain
         
CAB Seas         
Beaufort_____   -0    k   loss
CAA_________   -4    k   loss
East Siberian__   -18    k   loss
Central Arctic_   -17    k   loss
         
Kara_________   -23    k   loss
Laptev_______    7    k   gain
Chukchi______   -8    k   loss
         
Other Seas         
Okhotsk______    1    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -27    k   loss

Area loss 118 k, 32 K MORE than the 2010's average loss of 86 k on this day.
EDIT
Total area 3rd 4th lowest 5th lowest, (31k greater than 2007, 74k greater than 2016, and 220k greater than 2012).

2012 is the front runner as regards area.
Other Stuff
Until the weekend GFS showing  temperature anomalies at +0.9 to +1.9 degrees celsius. During this time the images suggest high +ve anomalies in central and eastern Siberia, with contrasting and sometimes strong -ve anomalies for most of the time on land and coastal sea by and in the Beaufort/CAA and Western Siberia, and in contrast again mostly +ve anomaly over most of the Arctic Ocean.

Over the weekend the picture changes somewhat. By Monday the CAA gets warmer, NW Canada and Alaska get a lot colder, and on the Russian side warmth moves west into areas bordering the Laptev and Kara, while the ESS area switches from strong warmth to a cold snap. However, over the Arctic Ocean itself there is a modest +ve  temp anomaly. Overall the Arctic temp anomaly stays well below 1 degree celsius.

A complicated picture.

We are in the period of maximum daily area loss that lasts until late July.
Area losses have ticked up a lot in the last three days after retreating to well below average during the few days before.
________________________________________________________________________
Extent and area showing marked difference. See next post(s).
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1318 on: June 25, 2019, 02:34:16 PM »
NSIDC Data as at 24 June 2019 (5 day trailing average)

Graphs attached look at Tealight's "High Arctic" - the 7 seas - Kara, Laptev, ESS, Chukchi, Beaufort, CAA, and the 3.2. million km2 of the Central Arctic Sea/Basin.

Area shows 2019 maintaining its position between 2012 and 2016.
Extent shows 2019 in pole position.

The result is concentration (area divided by extent) tends to stay up, against the normal trend for concentration to go down as the season progresses. The last 2 days of very high area loss have reversed this a tad.

Tealight's High Arctic Cumulative AWP anomaly at the moment also shows steady progress to a 2nd highest value 'twixt 2012 and 2016.
_____________________________________________________________________
Overall the NSIDC data suggests progress towards a lowish minimum in September. My prediction that belongs to me of a 4 million km2 JAXA daily minimum , (not a km2 more, not a km2 less,) is still intact (so far).

PIOMAS June data could kick the whole thing into touch.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1319 on: June 25, 2019, 03:29:24 PM »
NSIDC Greenland Sea Data as at 24 June 2019 (5 day trailing average)

Papers written some years ago said that 90% of the ice leaving the Arctic Ocean was transported by the East Greenland current. So at this time melting is at war with fresh ice arriving from the Fram. At the moment, melting is winning. The NSIDC map shows this very well indeed. (look from South to North)
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1320 on: June 25, 2019, 04:11:53 PM »
NSIDC Baffin Bay Data as at 24 June 2019 (5 day trailing average)

Sometimes new stuff just arrives, such as the connection between Baffin Bay and the Greenland Sea.

The strong south flowing cold East Greenland Current becomes the weak West Greenland current flowing north as it rounds the southern tip of Greenland. It is shown as a cold current on the maps. The literature says it is known on occasion to be a warm current. It all depends on how much ice and cold polar water counteracts warmer Atlantic water from the south. On the NSIDC map you can see odd bits of ice all the way up the west coast of Greenland. A lot of ice down the Fram earlier this year? EDIT and the DMI SST anomaly says a warm West Coast.

Nevertheless, this year the Baffin Bay ice area is way below normal, following 2012 area.

At the far north of Baffin Bay down it comes again as the cold current famous for causing the Newfoundland Banks fogs and storms as it passes by the GUlf Stream farther offshore.
« Last Edit: June 25, 2019, 04:22:01 PM by gerontocrat »
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1321 on: June 25, 2019, 04:40:12 PM »
NSIDC  Data as at 24 June 2019 (5 day trailing average)

Barents Sea
Melt out = Ice In? Area well above 2010's average.

Kara Sea Fast melt. Area at 2010's average.

Laptev Sea Fast melt but today a hiccup up. Area at record lowest.

ESS Area loss barely started. Area at 2010's average.
________________________________________________________
Off to cut the hedge.

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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1322 on: June 25, 2019, 05:37:16 PM »
NSIDC  Data as at 24 June 2019 (5 day trailing average)

PACIFICATION

IM(not)HO, the Bering and Chukchi might give an indication of one future for the Arctic.

The Bering sea ice sort of collapsed in 2018, allowing early sea ice loss in the Chukchi (that was not maintained).
This year, the Bering sea, despite a very short-term spike in area in January, repeated that collapse.
The Chukchi sea ice area has reduced fast and been at record lows for most of the melting season so far. SST anomalies are even higher than in 2018. Area seems almost bound to continue at record lows.

There is considerable time left for the SST anomalies to increase in degrees and in area. What will happen come the Autumn and early winter. Will the Chukchi freeze really late? i.e. has the Bering Sea just passed a tipping point to a more or less permanent ice-free state?

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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1323 on: June 25, 2019, 07:50:03 PM »
NSIDC  Data as at 24 June 2019 (5 day trailing average)

The CAA, the Beaufort Sea & the 3.2 million KM2 Central Arctic Sea/Basin (aka The Big Beast) are worth considering as a group.

The CAA is losing area well above the 2010's average rate. And note how it looks like it just might avoid the 3 week hiatus in area loss that seems to be usual at this time. A bit of a mystery as the CAA has been a bit cool recently.

The Beaufort Sea quickly lost area to become lowest by the beginning of June. Then on the 10th June area loss stalled and then area started to increase to the extent that on this day area is 5th lowest in the satellite record. Much discussion on the melting season thread about changes in drift and wind affecting the Beaufort gyre.  The melting out of the Beaufort is delayed. (Caveat - volume/thickness)

The Central Arctic Basin area loss to date is well below the 2010's average. But the season has barely started so is of little significance. Of interest is that the lowest minimum was in 2016, not 2012. Perhaps this reflects loss of multi-year ice between 2012 and 2016. There is little doubt that this loss of multi-year ice has continued.

If the Arctic is reasonably warm from now on perhaps the volume and thickness of the Central Arctic Sea is critical ?
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1324 on: June 25, 2019, 08:14:49 PM »
NSIDC  Data as at 24 June 2019 (5 day trailing average)

And to finish - the Okhotsk, the Hudson & my favourite, the St. Lawrence

The Okhotsk maxed above the 2010's average, melted out very fast and approached zero well before the 2010's average.

The Hudson is melting out at the 2000's average but a week or so ahead of 2018. It will be done as near as makes no difference in 5 weeks or even less.

The St. Lawrence. The universal opinion is that there is zero ice here. Spurious, artefacts***. Huh, you're all a bunch of unbelievers. The graph proves it!!!
_________________________________________________________
*** artefact - something observed in a scientific investigation or experiment that is not naturally present but occurs as a result of the preparative or investigative procedure.
___________________________________________________________________

After all that,
NSIDC September average will be 4.25 million km2.
JAXA daily extent minimum will be 4.00 million km2, on October 1st to cause maximum confusion

I have decided this using royal privilege.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1325 on: June 25, 2019, 08:52:47 PM »
The St. Lawrence. The universal opinion is that there is zero ice here. Spurious, artefacts***. Huh, you're all a bunch of unbelievers.

The final proof from the University of Bremen is attached
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magnamentis

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Re: 2019 sea ice area and extent data
« Reply #1326 on: June 25, 2019, 08:57:19 PM »
The St. Lawrence. The universal opinion is that there is zero ice here. Spurious, artefacts***. Huh, you're all a bunch of unbelievers.

The final proof from the University of Bremen is attached

who still believes that there is ice in lawrence and has been for a while is "helplessly lost"

no reasoning will help because the moment we start to believe that at water temps between 7 and 15C there can survive ice in visible, sensible or any amounts is not open to common sense and only costs anyone else time and energy in vain.

https://climatereanalyzer.org/wx/DailySummary/#sst

Pmt111500

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Re: 2019 sea ice area and extent data
« Reply #1327 on: June 25, 2019, 09:05:41 PM »
Perfect <Gerontocrat>, I'll just swing ESS and Beaufort into Pacification section in my mind and I'm all set to follow the rest of the melting season!
Cooling the outside by heat pump.

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Re: 2019 sea ice area and extent data
« Reply #1328 on: June 26, 2019, 02:04:21 AM »
Thank you gerontocrat for all of this data...you are a daily go to source for me.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1329 on: June 26, 2019, 05:45:23 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
June 25th, 2019:
     9,504,475 km2, a drop of -93,434 km2.
     2019 is 6th lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

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

Michael Hauber

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Re: 2019 sea ice area and extent data
« Reply #1330 on: June 26, 2019, 07:21:16 AM »
The St. Lawrence. The universal opinion is that there is zero ice here. Spurious, artefacts***. Huh, you're all a bunch of unbelievers.

The final proof from the University of Bremen is attached

Is the labrador area part of St Lawrence or Baffin?  I see some ice on the 13th June.  Cloudy since then, that ice survived at least another couple days, was definitely breaking up, but hard to tell with all the cloud whether its 100% gone now.  Most of the Gulf of St Lawrence can be seen ice free as at the 13th.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Niall Dollard

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Re: 2019 sea ice area and extent data
« Reply #1331 on: June 26, 2019, 07:46:34 AM »
If it is purely St Lawrence Id agree with Ger that the 2500 km2 or so remaining are artefacts.

Wip's graphs show zero ice.

There is a small bit still on the Labrador coast.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1332 on: June 26, 2019, 08:44:01 AM »
JAXA ARCTIC EXTENT :-  9,504,475 km2(June 25, 2019)

- Extent is 6th lowest in the satellite record.
- Extent loss on this day 93 k, 29 k MORE than the average loss on this day of 69 k.
- Extent loss from maximum 4,767 k, 159 k (3.04%) greater than the average of 4,608 k loss from maximum by this day,
- On average 46.6% of the melting season done, with 80 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.23 million km2, 4th lowest in the satellite record, and 1.05 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt gives a result of 4.32 million km2, 6th lowest, and 1.14 million km2 above 2012.

Other Stuff

Over the next 7 days GFS showing  temperature anomalies at +0.8 to +1.7 degrees celsius. Until the weekend the images suggest high +ve anomalies in central and eastern Siberia, with contrasting and sometimes strong -ve anomalies for most of the time on land and coastal sea by and in the Beaufort/CAA and Western Siberia, and in contrast again mostly +ve anomaly over most of the Arctic Ocean.

Over the weekend the picture changes somewhat. By Monday the CAA gets warmer, NW Canada and Alaska get a lot colder, and on the Russian side warmth moves west into areas bordering the Laptev and Kara, while the ESS area switches from strong warmth to a cold snap. However, over the Arctic Ocean itself there is a modest +ve  temp anomaly. Overall the Arctic temp anomaly stays well below 1 degree celsius.

A complicated picture inadequately described above.

We are now entering the period of maximum daily extent loss that lasts until mid or late July and then very gradually declines. For a change, extent loss on this day well above average.

_____________________________________________________________________
The volume data for June should be available by late next week. It will be interesting to see what has happened to volume and perhaps more importantly, thickness during this month.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

iceman

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Re: 2019 sea ice area and extent data
« Reply #1333 on: June 26, 2019, 11:32:46 AM »
UH AMSR2 data is showing more high latitude sea ice extent and area in the arctic basin, than the highest melt years.


a reminder of this astute point that Oren made in the melting season thread:

CAB area at this time of year is a proxy for the area north of the Barents and the Fram, as the rest of the CAB is still mostly 100% sea ice until the beginning of July. As this year the transpolar drift is back with a vengeance, it is no surprise that CAB area is staying on the high side. As the Chukchi + Beaufort deteriorate, it is expected that the CAB will be hit first by loss of ice from its Pacific side.


gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1334 on: June 26, 2019, 12:27:44 PM »

who still believes that there is ice in lawrence and has been for a while is "helplessly lost"

no reasoning will help because the moment we start to believe that at water temps between 7 and 15C there can survive ice in visible, sensible or any amounts is not open to common sense and only costs anyone else time and energy in vain.

You are using two redundant methodologies, namely the use of facts and reason, to dispute my findings.
This will not do.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

JayW

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Re: 2019 sea ice area and extent data
« Reply #1335 on: June 26, 2019, 12:28:03 PM »
Jaxa AMSR2 Arctic sea ice volume calculated by Wipneus
https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf
"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1336 on: June 26, 2019, 01:33:28 PM »
Jaxa AMSR2 Arctic sea ice volume calculated by Wipneus
I think you have just chucked a grenade into the arena.
And if PIOMAS come up with something similar next week.......
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

oren

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Re: 2019 sea ice area and extent data
« Reply #1337 on: June 26, 2019, 02:30:14 PM »
Bear in mind AMSR2 volume does not measure volume... it is just an unreliable number.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #1338 on: June 26, 2019, 04:11:48 PM »
You guys need to use snark emoticon for the newbies when you say these things

be cause

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Re: 2019 sea ice area and extent data
« Reply #1339 on: June 26, 2019, 04:41:28 PM »
   .. don't throw the newbies out with the meltwater .. :)

 .. that grenade has been lying in full view for a few months .. AMSR2 figures suggest the detonator has gone off .. the main charge is time delayed . Handle with caution !
  .. and don't say you weren't warned ... b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

magnamentis

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Re: 2019 sea ice area and extent data
« Reply #1340 on: June 26, 2019, 04:59:23 PM »
Bear in mind AMSR2 volume does not measure volume... it is just an unreliable number.

very reliable IMO, AMSR2 measures concentration and therefore area very reliably at higest resolution and calculating the volume from there has provided very accurate results in the past, they're just not as popular like others when it comes to volume calculations.

Further those numbers represent exactly what is in plain sight for all of us who believe what we see.

Tor Bejnar

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Re: 2019 sea ice area and extent data
« Reply #1341 on: June 26, 2019, 05:49:23 PM »
I asked someplace if grid size was adequate for discerning area, etc.  A-Team was kind enough to have a look at the question and came up with a clear "No."  His review included AMSR2.  Review his work at the link.  He recommends "decide how you would classify individual grid cells" as to their extent or area.  My sense is there is a great deal of ambiguity where it matters (dispersed very small floes).
Quote
TorB asks: are ground resolutions of satellite images adequate for computing accurate extent, area, concentration, and volume in summer, given floes floating in open water/slush?
No. The grid cells are far too big in some forum products relative to the size distribution of floes in summer. Error soars as grid cells begin to depart from the intrinsic scale provided by floe sizes.
It is true that comparing this year's data (or calculations) with previous year's data using a single metric (NSIDC or AMSR2, etc.) is useful.  One question most of us don't ask is "What would the best metric be, given the data that has been available for several years?"  Occasionally, the gifted among us use pixel counts of things on a map presentation.  Would that give us 'better' numbers?
« Last Edit: June 26, 2019, 08:10:52 PM by Tor Bejnar »
Arctic ice is healthy for children and other living things.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1342 on: June 26, 2019, 06:47:12 PM »
NSIDC Total Area as at 25 June 2019 (5 day trailing average) 7,587,074  km2
                        
Total Area         
 7,587,074    km2      
-279,847    km2   <   2010's average.
-264,771    k   <   2018
-894,676    k   <   2000's average.
         
Total Area Change   -111    k   loss
Peripheral Seas   -28    k   loss
Central Seas__   -50    k   loss
Other Seas___   -34    k   loss
         
Peripheral Seas         
Bering _______    1    k   gain
Baffin  Bay____   -12    k   loss
Greenland____   -16    k   loss
Barents ______   -1    k   loss
         
CAB Seas         
Beaufort_____   -1    k   loss
CAA_________    2    k   gain
East Siberian__   -11    k   loss
Central Arctic_   -13    k   loss
         
Kara_________   -21    k   loss
Laptev_______    0    k   gain
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______    1    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -35    k   loss

Area loss 111 k, 26 K MORE than the 2010's average loss of 85 k on this day.

Total area 4th lowest[/b], (69k greater than 2016, and 205k greater than 2012).
2012 is the front runner as regards area.

Other Stuff
Over the next 7 days GFS showing  temperature anomalies at +0.8 to +1.7 degrees celsius. Until the weekend the images suggest high +ve anomalies in central and eastern Siberia, with contrasting and sometimes strong -ve anomalies for most of the time on land and coastal sea by and in the Beaufort/CAA and Western Siberia, and in contrast again mostly +ve anomaly over most of the Arctic Ocean.

Over the weekend the picture changes somewhat. By Monday the CAA gets warmer, NW Canada and Alaska get a lot colder, and on the Russian side warmth moves west into areas bordering the Laptev and Kara, while the ESS area switches from strong warmth to a cold snap. However, over the Arctic Ocean itself there is a modest +ve  temp anomaly. Overall the Arctic temp anomaly stays well below 1 degree celsius.

A complicated picture inadequately described above.

We are in the period of maximum daily area loss that lasts until late July.
Area losses have ticked up a lot in the last four days after retreating to well below average during the few days before.
________________________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1343 on: June 26, 2019, 07:08:30 PM »
NSIDC daily extent numbers have been dropping steadily since the 15th.



oren

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Re: 2019 sea ice area and extent data
« Reply #1344 on: June 26, 2019, 08:05:52 PM »
Bear in mind AMSR2 volume does not measure volume... it is just an unreliable number.
I apologize for my wording, it should have been more nuanced, but it was not made in snark. AMSR2 really cannot measure thickness properly in summer, although it's not totally random. But judging by its volume will lead to unreliable conclusions.
These things are way above my pay grade, but here are supporting quotes I managed to find from ADS/JAXA, from seaice.de (Dr. Lars Kaleschke of Uni Hamburg if I am not mistaken), and from Wipneus who compared AMSR2 volume to PIOMAS volume.

Quote
Method for calculating sea ice thickness and melt ice concentration ratio products
The product of sea ice thickness and the melt pond concentration which is shown in the VISHOP is calculated from AMSR-E and AMSR2 data by using a research algorithm1) developed by K. Tateyama (Kitami Institute of Technology) and others in the Arctic research projects utilizing the IARC-JAXA Information System (IJIS) and satellite imagery (1st - 4th generations). This product is an essentially experimental and research product. This product has the effectiveness in the relative dry freezing seasons such as autumn, winter and spring (September – May), but cannot provide the accurate sea ice thickness in melting wet season (June - August) because the sea ice surface is covered by melt ponds.
This product is opened to the public for the usages of research and validation of algorithms. The Arctic Data archive System (ADS) is not liable for any loss or damage resulting from the use of this data.
Reference
1)   Krishfield, R. A., A. Proshutinsky, K.Tateyama, W. J. Williams, E. C. Carmack, F. A. McLaughlin, and M.-L. Timmermans (2014), Deterioration of perennial sea ice in the Beaufort Gyre from 2003to 2012 and its impact on he oceanic freshwater cycle, J. Geophys. Res.Oceans, 119, doi:10.1002/2013JC008999.

You can not trust these AMSR2 thickness maps. From these kind of microwave radiometer you can just derive a very uncertain proxy. For AMSR2 frequencies the penetration depth is not more than a few centimeters, therefore the signal comes just from the sea ice surface. It is rather related to snow grain sizes, layering and sea ice surface salinity.

Just posting this here, not completely on-topic but I might add Cryosat later.

This is AMSR2 volume, compared with PIOMAS, calculated from the ice thickness maps in the ADS Sea Ice monitor. Inverting the colorscale for thickness and calculating the area of each pixel (for a 10 km polar stereo graphic projection)  volume can be calculated.

I am ignoring:
-pole hole
-fraction of melting ice
-difference between PIOMAS domain and AMSR2 domain (I am using all the ice in the image).

There is a warning that the AMSR2 thickness is not reliable during the melting season, but at least we can say that the results are not all that crazy.

Here is PIOMAS, AMSR2-SIT and CRYOSAT compared.

[EDIT: fixed a bug in the AMSR2 volume calculation, the volume is noticeable smaller]


Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #1345 on: June 27, 2019, 05:55:33 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
June 26th, 2019:
     9,441,494 km2, a drop of -62,981 km2.
     2019 is 6th lowest on record.
     (2012 highlighted).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

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

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1346 on: June 27, 2019, 09:04:14 AM »
JAXA ARCTIC EXTENT :-  9,441,494 km2(June 26, 2019)

- Extent is 6th lowest in the satellite record.
- Extent loss on this day 63 k, 16 k less than the average loss on this day of 79 k.
- Extent loss from maximum 4,830 k, 143 k (3.1%) greater than the average of 4,687 k loss from maximum by this day,
- On average 47.4% of the melting season done, with 79 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 4.25 million km2, 4th lowest in the satellite record, and 1.07 million km2 above the 2012 low of 3.18 million km2.
Looking at the last 5 years average remaining melt gives a result of 4.32 million km2, 6th lowest, and 1.14 million km2 above 2012.

Other Stuff

A messy picture, GFS showing  temperature anomalies in a narrow range of +0.9 to +1.6 degrees celsius disguising movement of highs and lows over the land around the Arctic,  in contrast again with mostly +ve anomaly over most of the Arctic Ocean.

The CAA and Baffin Bay is mostly warm, with periods of warmth and cold in Western Canada and Alaska. High +ve anomalies most of the time in Central Siberia with periods of warmth and cold in Eastern and Western Siberia.

A complicated picture inadequately described above.

We are now entering the period of maximum daily extent loss that lasts until mid or late July and then very gradually declines. Extent loss on this day back below average.
_____________________________________________________________________
The volume data for June should be available by late next week. It will be interesting to see what has happened to volume and from that, perhaps more importantly, thickness during this month.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #1347 on: June 27, 2019, 02:24:05 PM »
NSIDC Total Area as at 26 June 2019 (5 day trailing average) 7,467,978  km2
                        
Total Area         
 7,467,978    km2      
-300,171    km2   <   2010's average.
-246,968    k   <   2018
-913,647    k   <   2000's average.
         
Total Area Change   -119    k   loss
Peripheral Seas   -18    k   loss
Central Seas__   -67    k   loss
Other Seas___   -34    k   loss
         
Peripheral Seas         
Bering _______    2    k   gain
Baffin  Bay____   -11    k   loss
Greenland____   -8    k   loss
Barents ______   -1    k   loss
         
CAB Seas         
Beaufort_____   -4    k   loss
CAA_________   -1    k   loss
East Siberian__   -17    k   loss
Central Arctic_   -14    k   loss
         
Kara_________   -17    k   loss
Laptev_______   -8    k   loss
Chukchi______   -7    k   loss
         
Other Seas         
Okhotsk______    2    k   gain
St Lawrence___   -0    k   loss
Hudson Bay___   -35    k   loss

Area loss 119 k, 22 K MORE than the 2010's average loss of 97 k on this day.

Total area 4th lowest[/b], (38k greater than 2016, and 202k greater than 2012).
2012 is the front runner as regards area.

Other Stuff
A messy picture, GFS showing  temperature anomalies in a narrow range of +0.9 to +1.6 degrees celsius disguising movement of highs and lows over the land around the Arctic,  in contrast again with mostly +ve anomaly over most of the Arctic Ocean for most of the time.

The CAA and Baffin Bay is mostly warm, with periods of warmth and cold in Western Canada and Alaska. High +ve anomalies most of the time in Central Siberia with periods of warmth and cold in Eastern and Western Siberia.

A complicated picture inadequately described above.

We are in the period of maximum daily area loss that lasts until late July.
Area losses have ticked up a lot in the last five days after retreating to well below average during the few days before.
________________________________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #1348 on: June 27, 2019, 04:56:13 PM »
NSIDC daily extent
Column E is daily drop, Column F is 5-day average


Rich

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Re: 2019 sea ice area and extent data
« Reply #1349 on: June 27, 2019, 05:43:36 PM »
 Average area loss over the last half of June is over 100k per day. That would get us to zero in September if we kept that pace. I'm guessing we'll slow down.