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jplotinus

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Re: 2018 sea ice area and extent data
« Reply #1400 on: August 16, 2018, 05:16:42 AM »
New JAXA data posted through 14 August!

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #1401 on: August 16, 2018, 05:24:46 AM »
ADS-NIPR (JAXA)
:D
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.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #1402 on: August 16, 2018, 05:49:07 AM »
[ADS-NIPR-JAXA] ASI Extent.  ;)

August 15th, 2018: 5,333,478 km2, a drop of -87,387 km2.
2018 is the sixth lowest on record.
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.

Wherestheice

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Re: 2018 sea ice area and extent data
« Reply #1403 on: August 16, 2018, 05:52:15 AM »
Finally!
"When the ice goes..... F***

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1404 on: August 16, 2018, 07:33:07 AM »
JAXA ARCTIC EXTENT 5,333,478 km2(August 15, 2018)

Back again and now within the last month of the melting season (on average).

Just to add to Juan's post...

- Extent losses above and below average in the last 4 days,
- Extent is now 69 k km2  (1.3 %) below the 2010's average extent on this date,
- and 130 k (2.4%) above 2017 (which is about to start a series of below average extent losses) ,
- Extent loss to date is now 305 km2 (3.4 %) below the 2008-2017 average, with 89 % of the average melting season done.

Resulting minimum from average remaining melt is  4.23 million km2, (excluding 2012 from the average gives 4.26 million km2 - an insignificant difference). Range of results from last ten years remaining melt is 3.96 to 4.60 million km2 - also a narrowing range. For a minimum at 2nd lowest remaining melt needs to be about 15% above average. For a new record low remaining melt would need to be 2.16 million km2 as opposed to the average remaining melt of 1.10 million km2, i.e 1.06 million (96 %) above the average. Not feasible.

Of interest (?) is that in 2012 melt from this point was just 0.27 million (25%) above the average remaining melt.

That 2017 feeling wanes and waxes- extent losses are only slowly (or not at all) catching up on the slow melt to date and NSIDC Area losses have slowed significantly. There is, on average, just 11% (28 days) of further extent loss to go. Could the melting season last a bit longer than that - Yes.  On the other hand, could extent loss sharply reduce? Yes.

A September minimum in the range of 4.00 to 4.50 million km2 seems probable, with the result of least drama at 0.2 million km2 above 2nd place and about 1 million km2 above the 2012 outlier.
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Sterks

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Re: 2018 sea ice area and extent data
« Reply #1405 on: August 16, 2018, 08:34:31 AM »
[ADS-NIPR-JAXA] ASI Extent.  ;)

August 15th, 2018: 5,333,478 km2, a drop of -87,387 km2.
2018 is the sixth lowest on record.

It's noteworthy how all the 2010s except for the freak 2012 and its rebounds '13 and '14, bundle up all together so nicely in extent at such late date of the season. So different melt seasons and yet it is like they hit a rock here. Bathymetry I'd say. An abrupt step that will take time (when all years are like 2012) to be broken in regular basis.

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1406 on: August 16, 2018, 02:18:29 PM »
NSIDC Total Area as at 15 August (5 day trailing average) =   4,071,757 km2
This is now 291 k above the 2010-2017 average total area for this date


Total Area loss 45 K ,

Central Seas loss         41 k,
Peripheral Seas loss       1 k, all seas at or near zero area.
Other Seas loss             3 k. all seas at or near zero area.

Analysis of individual seas.
Pacific Side
- The Bering Sea - finished,
- Chukchi Sea loss 4 k, area 94k, a bit below the 2010's average.
Atlantic Side
- Baffin Sea loss 0 k, area 29 k - almost done,
- Greenland Sea loss 1 k, area 69k,
- Barents Sea - finished,
- The Kara Sea area loss 1 k, area is now 29 k, well under 5% of 1980's average maximum.
- The Laptev Sea area loss 7 k,  area 57 k, <8% of maximum.

CAB
- Beaufort Sea gain 2 k,
- The Canadian Archipelago gain 0 k,
- East Siberian Sea loss 38 k .
- The Central Arctic Sea gain 7 k,

Other seas

- St Lawrence -finished,
- Hudson Bay area loss 3 k, Area now 34 k,
- The Okhotsk Sea - finished

On average, this is when daily area loss declines sharply  But the area loss of 45 k is above this day's 2010's average by 13 k. Extent loss (also 5-day trailing average)) was 71k, above average for the day. And daily extent loss was 90k, after 128k, 106k  and 68k the days before..

It is all about the 4 central seas now. On the melting season thread there is evidence of strong ice loss along the Atlantic front all the way round to the ESS, and predictions of weather favourable for further ice loss. Will above average area losses return strongly in the last 30 days or so of the season ? Not seen for a good while but an uptick on this day.

The melting season ain't over yet.
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"And that's all I'm going to say about that". Forrest Gump
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AvantGuardian

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Re: 2018 sea ice area and extent data
« Reply #1407 on: August 16, 2018, 03:00:53 PM »
Funny how the 250m resolution of these scans causes the central pack disintegrating into slush to cause an area gain. ::)
Navy brat, student at Hawaiki state, majoring in oceanography, climate and parapsychology.

Stephan

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Re: 2018 sea ice area and extent data
« Reply #1408 on: August 16, 2018, 07:54:30 PM »
Thank you gerontocrat for this excellent analysis. To be honest - I look forward to reading your tables and accompanying comments and analyses every evening.
Please allow me to add / comment / speculate on some aspects:
1. I think that Bering, Barents and Okhotsk are really free of ice.
2. I wonder how much of this "non-ice" is hidden in the Hudson and Baffin numbers. Can this number already be a two-digit percentage of the area?
3. If I extrapolate last week's losses the only sea that can reach zero seems to be Laptev. Whether there will be sufficient losses for an "about zero value" is achievable for Hudson, Baffin and Kara is highly questionable.
4. ESS has shown big progress in the last days. Strong westerly winds may put further ice out into Chukchi Sea, supported by well above 0°C the next days.

I think this melting season is very interesting.
It is too late just to be concerned about Climate Change

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1409 on: August 16, 2018, 08:53:33 PM »

2. I wonder how much of this "non-ice" is hidden in the Hudson and Baffin numbers. Can this number already be a two-digit percentage of the area?
3. If I extrapolate last week's losses the only sea that can reach zero seems to be Laptev. Whether there will be sufficient losses for an "about zero value" is achievable for Hudson, Baffin and Kara is highly questionable.
4. ESS has shown big progress in the last days. Strong westerly winds may put further ice out into Chukchi Sea, supported by well above 0°C the next days.

I think this melting season is very interesting.

Hullo Stephan.

Two things to talk about.

Non-ice
The AMSR2 resolution is by grid elements far smaller in area than from NSIDC. This means non-ice is a much bigger problem with NSIDC. An interesting example seems to be visible right now in the Kara Sea. NSIDC says area of ice remaining is about 29,000 km2, see inside the ringed area on the 1st image. The JAXA AMSR2 (2nd) image says there is no ice there. I think I believe the JAXA image.

What is nearly ice free ?
The convention for an Arctic Blue Ocean Event (BOE) is ice extent less than 1 million km2. This is about 7% of the 1980's average winter maximum. I am using 5% to say that when area in a sea is less than 5% of maximum, that sea is as near ice-free as makes no difference.

Also, when you look at the graph of ice loss, loss usually slows down dramatically when ice extent or area is down to about 15% of maximum. At that point a sea is 85% open ocean. Indeed, if one imagined that NSIDC had each sea as one giant pixel, then when ice extent went down to 15%, NSIDC would say that extent = zero. It is fair to say, imo, that when a sea has lost 85% of its area, it is no longer functioning as an ice-covered part of the ocean.

However, for the moment I am sticking with 5%.
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Stephan

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Re: 2018 sea ice area and extent data
« Reply #1410 on: August 16, 2018, 09:18:55 PM »
So the Kara sea ice area is only present in NSIDC analysis in the deep bay of Ob River mouth? If this is the case, then I will revise my posting from an hour ago - the Kara Sea is also ice free. (supported by Wipneus' graph on the "regional graphs" site of Arctic Sea Ice Graphs, which shows zero for Kara Sea since at least two weeks).
It is too late just to be concerned about Climate Change

litesong

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Re: 2018 sea ice area and extent data
« Reply #1411 on: August 16, 2018, 10:43:28 PM »
It's noteworthy how all the 2010s except for the freak 2012 and its rebounds '13 and '14, bundle up all together so nicely in extent at such late date of the season. So different melt seasons and yet it is like they hit a rock here.
Since solar TSI has been sub-normal for 12(+?) years (including 3+ years of TSI setting a 100 year record low), such ice loss potential information must be considered, especially during the excess hours of sunlight per day in the Arctic in mid to late spring & into early & mid-summer. Presently, I am surprised that far more sea ice isn't in the Arctic. The stupendous rise of recent atmospheric GHGs & their positive feedbacks must account for the ice not returning to decades past levels. Major accelerations of TSI assisted ice loss, must occur when the sun does return to full TSI level.

magnamentis

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Re: 2018 sea ice area and extent data
« Reply #1412 on: August 16, 2018, 11:06:53 PM »
Folks, does this helps?
Great, Ivica!
I recommend to read the original article:
https://blogs.egu.eu/divisions/cr/2018/02/09/image-of-the-week-the-gap-the-bridge-and-the-game-changer/

Maybe a break in the data is good... We already know what's happening, easily see the effects and might finally have time to GO DO something about it!

I completely agree with you!  :)

a nice thought but since when does one thing exclude the other ?

or in other words, if someting is done it's lastly because of all the data and what keeps anyone from doing something only because new data is dropping in?

as i said, a nice thought the way it's meant but still more an expression of feelings than really true.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #1413 on: August 17, 2018, 02:13:28 AM »
a nice thought but since when does one thing exclude the other ?

As an individual person, I'm sure that some of us can be active fighting anthropogenic global warming. But as a group belonging to a Forum, I don't see that we are promoting activism. The Forum is design to share information, not to make social movements.

So, I wonder what would happen on this Forum, if suddenly all the satellites stop working and we become blind. And the true is that, with the knowledge we have, we can be socially active on several subjects. So, -as a group- do you believe that: "We already know what's happening, easily see the effects and might finally have time to GO DO something about it!"?

Anyway, this belong to another topic, if someone is looking to open it (maybe on "Policy and Solutions"). Let's return to the Arctic sea ice area and extent.
« Last Edit: August 17, 2018, 03:56:30 AM by Juan C. García »
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.

Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #1414 on: August 17, 2018, 05:52:27 AM »
[ADS-NIPR-JAXA] ASI Extent.  ;)

August 16th, 2018: 5,248,792 km2, a drop of -84,686 km2.
2018 is the fifth lowest on record.
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.

GoSouthYoungins

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Re: 2018 sea ice area and extent data
« Reply #1415 on: August 17, 2018, 05:58:00 AM »
a nice thought but since when does one thing exclude the other ?

As an individual person, I'm sure that some of us can be active fighting anthropogenic global warming. But as a group belonging to a Forum, I don't see that we are promoting activism. The Forum is design to share information, not to make social movements.

So, I wonder what would happen on this Forum, if suddenly all the satellites stop working and we become blind. And the true is that, with the knowledge we have, we can be socially active on several subjects. So, -as a group- do you believe that: "We already know what's happening, easily see the effects and might finally have time to GO DO something about it!"?

Anyway, this belong to another topic, if someone is looking to open it (maybe on "Policy and Solutions"). Let's return to the Arctic sea ice area and extent.

I'm happy to have this thread polluted with calls for action. The specifics at this point are doom porn. We have the information we need. It is time for action, starting with resolution on appropriate plan of action.
big time oops

SteveMDFP

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Re: 2018 sea ice area and extent data
« Reply #1416 on: August 17, 2018, 06:44:57 AM »

I'm happy to have this thread polluted with calls for action. 

Please don't.  This is "2018 sea ice area and extent data."  There are other places in the forum for such topics.  Please don't disrespect the community here.

GoSouthYoungins

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Re: 2018 sea ice area and extent data
« Reply #1417 on: August 17, 2018, 06:59:38 AM »

I'm happy to have this thread polluted with calls for action. 

Please don't.  This is "2018 sea ice area and extent data."  There are other places in the forum for such topics.  Please don't disrespect the community here.

Yikes. You tell me I'm off-thread in "Policy & Solutions" too. Maybe it is the message that's upsetting you. (on-topic: extent average relative to previous decade. shape of ice, very different.)
big time oops

etienne

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Re: 2018 sea ice area and extent data
« Reply #1418 on: August 17, 2018, 07:10:56 AM »

I'm happy to have this thread polluted with calls for action. 

Please don't.  This is "2018 sea ice area and extent data."  There are other places in the forum for such topics.  Please don't disrespect the community here.

Yikes. You tell me I'm off-thread in "Policy & Solutions" too. Maybe it is the message that's upsetting you. (on-topic: extent average relative to previous decade. shape of ice, very different.)

"Walking the walk" would be the right place to call for action. But I agree that it is not the most active part of the forum. I do believe that discussing without action afterward is somehow a waste of time, but I think and hope that most of us are active in their local community.

GoSouthYoungins

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Re: 2018 sea ice area and extent data
« Reply #1419 on: August 17, 2018, 07:22:37 AM »

I'm happy to have this thread polluted with calls for action. 

Please don't.  This is "2018 sea ice area and extent data."  There are other places in the forum for such topics.  Please don't disrespect the community here.

Yikes. You tell me I'm off-thread in "Policy & Solutions" too. Maybe it is the message that's upsetting you. (on-topic: extent average relative to previous decade. shape of ice, very different.)

"Walking the walk" would be the right place to call for action. But I agree that it is not the most active part of the forum. I do believe that discussing without action afterward is somehow a waste of time, but I think and hope that most of us are active in their local community.

I agree. And I get it, we shouldn't pollute the worlds best forum about the most telling and obvious climate change signal.  But there isn't anything near consensus relative to solutions here. If that's the case, I don't give a flying fuck if the ice is down 54% or 61%, why should anyone?
big time oops

jdallen

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Re: 2018 sea ice area and extent data
« Reply #1420 on: August 17, 2018, 08:37:33 AM »

I'm happy to have this thread polluted with calls for action. 

Please don't.  This is "2018 sea ice area and extent data."  There are other places in the forum for such topics.  Please don't disrespect the community here.

Yikes. You tell me I'm off-thread in "Policy & Solutions" too. Maybe it is the message that's upsetting you. (on-topic: extent average relative to previous decade. shape of ice, very different.)

"Walking the walk" would be the right place to call for action. But I agree that it is not the most active part of the forum. I do believe that discussing without action afterward is somehow a waste of time, but I think and hope that most of us are active in their local community.

I agree. And I get it, we shouldn't pollute the worlds best forum about the most telling and obvious climate change signal.  But there isn't anything near consensus relative to solutions here. If that's the case, I don't give a flying fuck if the ice is down 54% or 61%, why should anyone?
We do, because we are trying to relate changes in extent and area to other phenomena and metrics. We do, because we are trying to understand how the pieces fit, so we can both better predict and effectively argue. The numbers here are a repository.
This space for Rent.

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1421 on: August 17, 2018, 08:42:48 AM »
JAXA ARCTIC EXTENT 5,248,792 km2(August 16, 2018)

For those who do care a flying whatsit, herewith some more extent data.

Just to add to Juan's post...

- Extent is now 84 k km2  (1.6 %) below the 2010's average extent on this date,
- and 112 k (2.1%) above 2017 (which is about to start a series of below average extent losses) ,
- Extent loss to date is now 286 km2 (3.2 %) below the 2008-2017 average, with 89.6 % of the average melting season done.

Resulting minimum from average remaining melt is  4.21 million km2, (excluding 2012 from the average gives 4.24 million km2 - an insignificant difference). Range of results from last ten years remaining melt is 3.96 to 4.58 million km2 - also a narrowing range. For a minimum at 2nd lowest remaining melt needs to be about 14% above average. For a new record low remaining melt would need to be 2.07 million km2 as opposed to the average remaining melt of 1.03 million km2, i.e 1.04 million (100 %) above the average. Not feasible.

Of interest (?) is that in 2012 melt from this point was just 0.26 million (25%) above the average remaining melt.

That 2017 feeling wanes and waxes- extent losses are only slowly (or not at all) catching up on the slow melt to date and NSIDC Area losses have slowed significantly. There is, on average, just 10.4% (27 days) of further extent loss to go. Could the melting season last a bit longer than that - Yes.  On the other hand, could extent loss sharply reduce? Yes.

A September minimum in the range of 4.00 to 4.50 million km2 seems probable, with the result of least drama at 0.2 million km2 above 2nd place, 0.2 million km2 below 2017 and about 1 million km2 above the 2012 outlier.
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Jim Pettit

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Re: 2018 sea ice area and extent data
« Reply #1422 on: August 17, 2018, 01:49:29 PM »
I'm happy to have this thread polluted with calls for action. The specifics at this point are doom porn. We have the information we need. It is time for action, starting with resolution on appropriate plan of action.

While cluttering the forum with off-topic posts might make you happy, our experience has shown that most users prefer more focused, on-topic discussions, especially in the most popular threads such as this one, so kindly stay on the rails. There are threads here for talking about policies and solutions; this isn't one of them. Thanks!

Jim Pettit

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Re: 2018 sea ice area and extent data
« Reply #1423 on: August 17, 2018, 02:04:41 PM »
NSIDC SIE saw a much smaller than average drop yesterday of just 5k km2. Even so, 2018 is still on track for a minimum of around 4.47M km2 on or around the 12th, with a projected September average of about 4.63M.

The year-to-date NSIDC SIE average is still in 2nd place, just 42k above 1st place 2016 (and 391k below the same-day average for 2012).

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1424 on: August 17, 2018, 03:14:45 PM »
NSIDC Total Area as at 16 August (5 day trailing average) =   3,995,652 km2
This is now 241 k above the 2010-2017 average total area for this date


Total Area loss 76 K ,

Central Seas loss         73 k,
Peripheral Seas loss       3.5 k, all seas at or near zero area.
Other Seas gain             0.6 k. all seas at or near zero area.

Analysis of individual seas.
Pacific Side
- The Bering Sea - finished,
- Chukchi Sea loss 5 k, area 89 k, below the 2010's average - just.
Atlantic Side
- Baffin Sea loss 1 k, area 29 k - almost done,
- Greenland Sea loss 3 k, area 67k,
- Barents Sea - finished,
- The Kara Sea area loss 1 k, area is now 28 k, well under 5% of 1980's average maximum.
- The Laptev Sea area loss 6 k,  area 51 k, 6% of maximum.

CAB
- Beaufort Sea loss 6 k,
- The Canadian Archipelago loss 4 k,
- East Siberian Sea loss 41 k .
- The Central Arctic Sea loss 9 k,

Other seas

- St Lawrence -finished,
- Hudson Bay area gain 1 k, Area now 35 k,
- The Okhotsk Sea - finished

On average, this is when daily area loss declines sharply  But the area loss of 73 k is above this day's 2010's average by 50 k. Extent loss (also 5-day trailing average)) was 79k, above average for the day. But daily extent loss was a mere 5k, after the recent high losses of 90k,  128k, 106k  and 68k the days before..

It is all about the 4 central seas now. On the melting season thread there is evidence of strong ice loss along the Atlantic front all the way round to the ESS, and predictions of weather favourable for further ice loss. Will above average area losses return strongly in the last 30 days or so of the season ? Not seen for a good while but an real difference on this day, especially (at last) in the ESS - Atlantification heads East? (see graph)

The melting season ain't over yet.
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1425 on: August 17, 2018, 04:15:52 PM »
Putting out the data on a daily basis is interesting, and despite the odd offhand comments to the contrary, most people seem to feel it has value.

But now as the season comes to an end, the question the data asks me is - "what was the story this melting season?" Of course the story ain't over yet but using graphs I would like to tell - as I see it - the story so far. I see it as a tale of two ends - the Pacific and the Atlantic, and may take some time as I look through the data.

At the beginning I thought(as did many others?) it was going to be all about the Pacific end. NOAA / NASA said it was that end that had the highest temperature anomalies (for several years), and low and behold, the Bering Sea Ice collapsed in front of our eyes.

This opened up the Chukchi Sea to Pacific air and ocean warmth, and the ice in the Chukchi initially obliged with an early melt, but by early June area was back to 2010's and 2000's average.

The Beaufort and Eastern Siberian Seas have also been slow to lose ice from the Pacific end, area usually well below the 2010's average.

End of end 1....

"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1426 on: August 17, 2018, 08:54:01 PM »
Atlantic End

- East Coast of US and Canada.

It was cold there early in the year. Both the St. Lawrence and Baffin Seas had higher than average maxima. But while area in the St. Lawrence then collapsed from March, the Baffin has been slow to melt for the whole season, though now more or less completely melted out.
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bbr2314

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Re: 2018 sea ice area and extent data
« Reply #1427 on: August 17, 2018, 09:20:18 PM »
Is it possible to do Foxe Basin alone?

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1428 on: August 17, 2018, 09:31:14 PM »
Is it possible to do Foxe Basin alone?
Sorry. I use area data as analysed by NSIDC's 14 seas.. Anything beyond that is beyond my capability.
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Michael Hauber

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Re: 2018 sea ice area and extent data
« Reply #1429 on: August 17, 2018, 11:22:17 PM »
Putting out the data on a daily basis is interesting, and despite the odd offhand comments to the contrary, most people seem to feel it has value.

But now as the season comes to an end, the question the data asks me is - "what was the story this melting season?" Of course the story ain't over yet but using graphs I would like to tell - as I see it - the story so far. I see it as a tale of two ends - the Pacific and the Atlantic, and may take some time as I look through the data.

At the beginning I thought(as did many others?) it was going to be all about the Pacific end. NOAA / NASA said it was that end that had the highest temperature anomalies (for several years), and low and behold, the Bering Sea Ice collapsed in front of our eyes.

I think a lot of people did expect big things on the Pacific side.  One thing though is that PIOMAS data at end of May showed that Siberia/Laptev ice was about the thickest of any recent years, with Beaufort being more typical and ice towards Greenland being on the thin side.  In some ways I thought there was potential for an all or nothing year this year - a savage melt season would have still taken out the thicker ice towards Russia, and attacked the thinner ice towards Greenland.  But an average melt season, or possibly poor melt season with slow start and stronger melt weather in August, allowed lots of this thicker ice to survive (so far).
Climate change:  Prepare for the worst, hope for the best, expect the middle.

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1430 on: August 17, 2018, 11:44:06 PM »
The Greenland Sea.

This little sea (maximum area 700,000 km2) has a story all to itself. Pourquoi? It's intimate relationship with the big beast round the corner - the 3.2 million km2 of the Central Arctic Sea, from which ice emerges and travels down the Fram Strait.

https://en.wikipedia.org/wiki/Fram_Strait
Quote
The Fram Strait is the passage between Greenland and Svalbard, located roughly between 77°N and 81°N latitudes and centered on the prime meridian. The Greenland and Norwegian Seas lie south of Fram Strait, while the Nansen Basin of the Arctic Ocean lies to the north. Fram Strait is noted for being the only deep connection between the Arctic Ocean and the World Oceans. The dominant oceanographic features of the region are the West Spitsbergen Current on the east side of the strait and the East Greenland Current on the west.
Fram Strait is the northernmost ocean area having ice-free conditions throughout the year. The width of the strait is about 450 km, but because of the wide continental shelves of Greenland and Spitsbergen, the deep portion of Fram Strait is only about 300 km wide. The ocean over the Greenland continental shelf is often covered with ice.
Bathymetry map attached.

In late February, the great warming event North of Greenland pushed ice northwards of Greenland. Export of ice down the Fram Strait stopped. Greenland sea ice area crashed. The event over, normality returned, export of ice resumed and sea ice area increased somewhat. The relationship between Fram ice export and Greenland Sea ice area is shown in the attached graph.

In the last few years, export of thick long-lasting multi-year (MYI) ice down the Fram has reduced simply because most of it has gone. With reduced ice export, and none since June 1, the effect of AGW seems to have become apparent. There is not a lot of ice area left. (See last attached graph).

This looks like a sea that in the future will be one that just occasionally has some ice (Central Arctic Sea being the Fat Controller).
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oren

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Re: 2018 sea ice area and extent data
« Reply #1431 on: August 18, 2018, 12:09:08 AM »
Putting out the data on a daily basis is interesting, and despite the odd offhand comments to the contrary, most people seem to feel it has value.

But now as the season comes to an end, the question the data asks me is - "what was the story this melting season?" Of course the story ain't over yet but using graphs I would like to tell - as I see it - the story so far. I see it as a tale of two ends - the Pacific and the Atlantic, and may take some time as I look through the data.

At the beginning I thought(as did many others?) it was going to be all about the Pacific end. NOAA / NASA said it was that end that had the highest temperature anomalies (for several years), and low and behold, the Bering Sea Ice collapsed in front of our eyes.

This opened up the Chukchi Sea to Pacific air and ocean warmth, and the ice in the Chukchi initially obliged with an early melt, but by early June area was back to 2010's and 2000's average.

The Beaufort and Eastern Siberian Seas have also been slow to lose ice from the Pacific end, area usually well below the 2010's average.

End of end 1....
Gerontocrat, thank you for the interesting analysis (as well as the daily data and analysis). I think it should be said regarding the Pacific side, while indeed the late freeze in the Chukchi and Bering, and the early opening of both gave expectations that the Beaufort and ESS would be hit hard as well, in reality a major feature of this melting season IMHO was a lot of movement of ice into the Beaufort, both from the central arctic and from the direction of the ESS. So the Beaufort data hides effects on the ice elsewhere. Even during winter, the string of old thick ice extended all the way along the Beaufort and Chukchi, and served as protection from aggressive melt during the middle part of the melting season in these seas.
The ESS had higher than normal volume for its own protection, as already mentioned above.

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Re: 2018 sea ice area and extent data
« Reply #1432 on: August 18, 2018, 12:35:01 AM »
The Barents, Kara and Laptev Seas.
It was very very cold in march and April up North. Even the UK got the "beast from the east". It shows in the fairly high sea ice maxima of the Barents and Kara seas. As May progressed, so did the formation of the blocking high stretching from Europe south west across the Atlantic. A long heatwave for Europe a wet cool summer for Iceland and persistent warmish wettish weather up the Greenland and Norwegian seas into the high Arctic.

This shows in the very fast ice loss starting from May / June in these three seas leading to what may well end up as record minima (and certainly near record low minima) for the Kara and Laptev seas.

The question in my mind is whether this is just a one-off event due to this unusual long lasting summer weather, or a major step-change towards Atlantification of the Arctic Ocean.

Eastern Siberian Sea.
In my first post in this series that seems like a saga, I cheated by not showing the sudden loss of ice in this sea in the last three days. This is because "my speculation that belongs to me" says that this sudden loss in sea ice comes from air and water from the Atlantic, not the Pacific.

Off for a think about the CAA and the Central Arctic Sea and a kip.
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1433 on: August 18, 2018, 12:48:06 AM »
... in reality a major feature of this melting season IMHO was a lot of movement of ice into the Beaufort, both from the central arctic and from the direction of the ESS. So the Beaufort data hides effects on the ice elsewhere. Even during winter, the string of old thick ice extended all the way along the Beaufort and Chukchi, and served as protection from aggressive melt during the middle part of the melting season in these seas.
The ESS had higher than normal volume for its own protection, as already mentioned above.
After posting, one always thinks but why did I not add... That persistent (2+ months) weather pattern sending wind and water anti clockwise up the North Atlantic and eastwards along the Russian side - did it effectively shovel the whole Arctic Sea Ice sideways?
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Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #1434 on: August 18, 2018, 05:50:52 AM »
[ADS-NIPR-JAXA] ASI Extent.

August 17th, 2018: 5,216,761 km2, a drop of -32,031 km2.
2018 is the fifth lowest on record.
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: 2018 sea ice area and extent data
« Reply #1435 on: August 18, 2018, 11:12:21 AM »
Before I add to Juan's post, just a bit more on area of individual seas.

Canadian Archipelago
Though not very big (circa 0.75 million km2 at maximum) it is this sea that captures the imagination - what with the NW Passage and being the graveyard of many an adventurer.

It was very cold up there this spring and early summer, of which we were reminded perhaps too often on perhaps too many threads. Melting started late, picked up, and then in June area increased - as it seems to do in most years. I've not seen an explanation for this odd annual event. However, this year area and extent loss have been very slow since. From posts on the melting season thread I gather that important channels have been bunged up, and the garlic press has not been in operation.

THE CENTRAL ARCTIC SEA
In late February that amazing event that pushed warmth northwards opened up the sea off the coast of Greenland - final proof that there is no truly landfast ice in the Arctic (as in the ice shelves of Antarctica).
Then the ocean froze back over. By May area and extent loss were well above average. But in early July area loss stopped and then reversed into gain, while extent loss continued. Area loss has resumed, but while extent loss is well above the 2010's average, area loss is well below. As Oren pointed out, this is much to do with ice being shoved westwards from the Atlantic front causing compaction as well. But perhaps of greater importance is that open ocean has reappeared North of Greenland

Just 4 weeks to go.
Will the Laptev and Greenland Seas completely melt out?
Will the ESS continue going down its August cliff?
Will the Beaufort Sea finally give up its ice?
Will the Garlic Press get into gear?

And in the Central Arctic Sea -
Will the Atlantic front push a bit further towards 85 North?
Will the ice North of Greenland continue to retreat?

ps: I have ignored the Okhotsk and the Hudson simply because.
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1436 on: August 18, 2018, 12:00:41 PM »
JAXA ARCTIC EXTENT 5,216,761 km2(August 17, 2018)

Just to add to Juan's post...

- Extent is now 59 k km2  (1.1 %) below the 2010's average extent on this date,
- and 113 k (2.2%) above 2017 (which has started a series of below average extent losses) ,
- Extent loss to date is now 311k km2 (3.5 %) below the 2008-2017 average, with 90.2 % of the average melting season done.

Resulting minimum from average remaining melt is  4.24 million km2, (excluding 2012 from the average gives 4.26 million km2 - an insignificant difference). Range of results from last ten years remaining melt is 4.02 to 4.59 million km2 - also a narrowing range. For a minimum at 2nd lowest remaining melt needs to be about 18% above average. For a new record low remaining melt would need to be 2.04 million km2 as opposed to the average remaining melt of 0.98 million km2, i.e 1.06 million (108 %) above the average. Impossible.

Of interest (?) is that in 2012 melt from this point was just 0.24 million (23%) above the average remaining melt.

That 2017 feeling wanes and waxes- just when it looks like the melting has some legs it slows again. There is, on average, just under 10% (26 days) of further extent loss to go. Could the melting season last a bit longer than that - Yes.  On the other hand, could extent loss sharply reduce? Yes.

A September minimum in the range of 4.00 to 4.50 million km2 seems probable, with the result of least drama at 0.2 million km2 above 2nd place, 0.2 million km2 below 2017 and about 1 million km2 above the 2012 outlier.
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1437 on: August 18, 2018, 03:09:59 PM »
NSIDC Total Area as at 17 August (5 day trailing average) =   3,919,769 km2
This is now 203 k above the 2010-2017 average total area for this date


Total Area loss 76 K ,

Central Seas loss         68 k,
Peripheral Seas loss       6 k, all seas at or near zero area.
Other Seas gain             2 k. all seas at or near zero area.

Analysis of individual seas.
Pacific Side
- The Bering Sea - finished,
- Chukchi Sea loss 5 k, area 84 k, below the 2010's average - just.
Atlantic Side
- Baffin Sea loss 1 k, area 28 k - almost done,
- Greenland Sea loss 5 k, area 62k,
- Barents Sea - finished,
- The Kara Sea area loss 0 k, area is now 28 k, well under 5% of 1980's average maximum.
- The Laptev Sea area loss 4 k,  area 47 k, 6% of maximum.

CAB
- Beaufort Sea loss 6 k,
- The Canadian Archipelago loss 5 k,
- East Siberian Sea loss 34 k .
- The Central Arctic Sea loss 13 k,

Other seas

- St Lawrence -finished,
- Hudson Bay area loss 2 k, Area now 33 k,
- The Okhotsk Sea - finished

On average, this is when daily area loss declines sharply  But the area loss of 76 k is above this day's 2010's average by 40 k. Extent loss (also 5-day trailing average)) was 71k, above average for the day. But daily extent loss was a mere 24k, after 5k the day before and before that the high losses of 90k,  128k, 106k  and 68k the days before.. This probably means that area losses will see a sharp fall in the coming days.

It is all about the 4 central seas now. On the melting season thread there is evidence of strong ice loss along the Atlantic front all the way round to the ESS, and predictions of weather favourable for further ice loss. Will above average area losses return strongly in the last 30 days or so of the season ? Not seen for a good while but an real difference on this day, especially (at last) in the ESS - Atlantification heads East?

The melting season ain't over yet, there is a chorus of fat ladies waiting in the wings for a chance to sing.
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oren

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Re: 2018 sea ice area and extent data
« Reply #1438 on: August 18, 2018, 03:55:48 PM »
Wow. The ESS lost 20% of its area in 3 days.

gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1439 on: August 18, 2018, 06:55:53 PM »
Wow. The ESS lost 20% of its area in 3 days.
It seems the melting season still has some surprises up its sleeve.

I attach the graphs for the four seas that are the ones that really matter. Incidentally these 4 seas are the only ones out of the 14 seas with area remaining at greater than 100,000 km2. And the Central Arctic Sea is the only one left with an area at more than 50% of its maximum.
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Wherestheice

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Re: 2018 sea ice area and extent data
« Reply #1440 on: August 18, 2018, 07:54:04 PM »
Before I add to Juan's post, just a bit more on area of individual seas.

Canadian Archipelago
Though not very big (circa 0.75 million km2 at maximum) it is this sea that captures the imagination - what with the NW Passage and being the graveyard of many an adventurer.

It was very cold up there this spring and early summer, of which we were reminded perhaps too often on perhaps too many threads. Melting started late, picked up, and then in June area increased - as it seems to do in most years. I've not seen an explanation for this odd annual event. However, this year area and extent loss have been very slow since. From posts on the melting season thread I gather that important channels have been bunged up, and the garlic press has not been in operation.

THE CENTRAL ARCTIC SEA
In late February that amazing event that pushed warmth northwards opened up the sea off the coast of Greenland - final proof that there is no truly landfast ice in the Arctic (as in the ice shelves of Antarctica).
Then the ocean froze back over. By May area and extent loss were well above average. But in early July area loss stopped and then reversed into gain, while extent loss continued. Area loss has resumed, but while extent loss is well above the 2010's average, area loss is well below. As Oren pointed out, this is much to do with ice being shoved westwards from the Atlantic front causing compaction as well. But perhaps of greater importance is that open ocean has reappeared North of Greenland

Just 4 weeks to go.
Will the Laptev and Greenland Seas completely melt out?
Will the ESS continue going down its August cliff?
Will the Beaufort Sea finally give up its ice?
Will the Garlic Press get into gear?

And in the Central Arctic Sea -
Will the Atlantic front push a bit further towards 85 North?
Will the ice North of Greenland continue to retreat?

ps: I have ignored the Okhotsk and the Hudson simply because.

Wait I was looking at that pic of the Jaxa thickness. According to that the ice is most thick around the center of the pack?? I thought all the thicker, multi-year ice was packed more towards the Canadian Arctic and Greenland?? Correct me if I’m wrong
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gerontocrat

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Re: 2018 sea ice area and extent data
« Reply #1441 on: August 18, 2018, 08:13:55 PM »

Wait I was looking at that pic of the Jaxa thickness. According to that the ice is most thick around the center of the pack?? I thought all the thicker, multi-year ice was packed more towards the Canadian Arctic and Greenland?? Correct me if I’m wrong

Suggest you take the thickness bit of the JAXA image with a large lump of salt. Maybe if it looks more or less the same several days in a row...I have more confidence in the parts showing less than 100% concentration.
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Wherestheice

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Re: 2018 sea ice area and extent data
« Reply #1442 on: August 18, 2018, 08:17:11 PM »

Wait I was looking at that pic of the Jaxa thickness. According to that the ice is most thick around the center of the pack?? I thought all the thicker, multi-year ice was packed more towards the Canadian Arctic and Greenland?? Correct me if I’m wrong

Suggest you take the thickness bit of the JAXA image with a large lump of salt. Maybe if it looks more or less the same several days in a row...I have more confidence in the parts showing less than 100% concentration.

Ah ok, thank you! Also IMO looking at the ESS it looks like it could all melt out. It looks very thin
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Re: 2018 sea ice area and extent data
« Reply #1443 on: August 18, 2018, 09:23:51 PM »
Regardless of how the next month of melting shakes out, I think there is strong evidence the refreeze will be really slow and thin this winter. Laptev, Barents, Greenland, Chukchi, and especially Bering seas all look set up to have poor freezing. The periphery seas may have rapid refreeze but it hardly matters. Any reasons to expect good freezing in the central and adjacent seas?
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Juan C. García

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Re: 2018 sea ice area and extent data
« Reply #1444 on: August 19, 2018, 06:12:28 AM »
[ADS-NIPR-JAXA] ASI Extent.

August 18th, 2018: 5,185,339 km2, a drop of -31,422 km2.
2018 is the sixth lowest on record.
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.

oren

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Re: 2018 sea ice area and extent data
« Reply #1445 on: August 19, 2018, 07:57:01 AM »
That 2017 feeling waxes again?

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Re: 2018 sea ice area and extent data
« Reply #1446 on: August 19, 2018, 08:40:39 AM »
It seems to be the case (if a two-days slow down of melting can already be interpreted as a (longer) trend...)
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Re: 2018 sea ice area and extent data
« Reply #1447 on: August 19, 2018, 09:01:06 AM »
JAXA ARCTIC EXTENT 5,185,339 km2(August 18, 2018)

Just to add to Juan's post...

- Extent is now just 36 k km2  (0.7 %) below the 2010's average extent on this date,
- and 91 k (1.8%) above 2017 (which has started a series of below average extent losses) ,
- Extent loss to date is now 337k km2 (3.7 %) below the 2008-2017 average, with 90.8 % of the average melting season done.

Resulting minimum from average remaining melt is  4.26 million km2, (excluding 2012 from the average gives 4.29 million km2 - an insignificant difference). Range of results from last ten years remaining melt is 4.06 to 4.56 million km2 - also a narrowing range. For a minimum at 2nd lowest remaining melt needs to be about 22% above average, very unlikely. For a new record low remaining melt would need to be 2.01 million km2 as opposed to the average remaining melt of 0.92 million km2, i.e 1.09 million (118 %) above the average. Impossible.

Of interest (?) is that in 2012 melt from this point was just 0.21 million (23%) above the average remaining melt.

That 2017 feeling wanes and waxes- just when it looks like the melting has some legs it slows again. There is, on average, under 10% (25 days) of further extent loss to go. Could the melting season last a bit longer than that - Yes.  On the other hand, could extent loss do a 2017 and sharply reduce? Yes.

A September minimum in the range of 4.00 to 4.50 million km2 seems probable, with the result of least drama at 0.2 million km2 above 2nd place, 0.2 million km2 below 2017 and about 1 million km2 above the 2012 outlier.
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Re: 2018 sea ice area and extent data
« Reply #1448 on: August 19, 2018, 09:11:03 AM »
That 2017 feeling waxes again?
2018 has been highly erratic, More increases in July than any other year and more declines over 200K. This could still end up almost anywhere above 4Mkm^2. 6 of the past  11 years have had declines above 900K after this date, 2017  was a complete aberration, the lowest decline since at least 2002.
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Re: 2018 sea ice area and extent data
« Reply #1449 on: August 19, 2018, 11:59:31 AM »
2018 has been highly erratic, More increases in July than any other year and more declines over 200K. This could still end up almost anywhere above 4Mkm^2. 6 of the past  11 years have had declines above 900K after this date, 2017  was a complete aberration, the lowest decline since at least 2002.

ESS and Canadian Archipelago are weakening fast now. This will show up in the numbers within a few days.
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