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Author Topic: The 2019 melting season  (Read 1069963 times)

sailor

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Re: The 2019 melting season
« Reply #6450 on: September 10, 2019, 08:41:55 AM »
Sep 3 - 9

5-day per-pixel minimum v. original Bremen concentration
If even the 5-day minimum is showing increases in the Western CAB, it can't be artifact.
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Aleph_Null

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Re: The 2019 melting season
« Reply #6451 on: September 10, 2019, 11:58:48 AM »
Hindcast: 9/6 to 9/10, Forecast: 9/10 to 9/14.
Wind + IWPD @ 850hPa [Instantaneous Wind Power Density: air density ρ, wind velocity v: ½ρv3]

uniquorn

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Re: The 2019 melting season
« Reply #6452 on: September 10, 2019, 12:20:29 PM »
Polarview sentinel1, western cab, sep9   https://www.polarview.aq/arctic

Freegrass

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Re: The 2019 melting season
« Reply #6453 on: September 10, 2019, 01:42:58 PM »
Wind @ Surface Forecast

2019-09-10 09:00 UTC
2019-09-15 06:00 UTC

I'll be posting a maximum of one animation a day on this thread. I hope that's not too much for some? If it is, let me know! More Nullschool animations can be found here.
https://forum.arctic-sea-ice.net/index.php/topic,2905.0.html
« Last Edit: September 10, 2019, 02:08:56 PM by Freegrass »
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SimonF92

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Re: The 2019 melting season
« Reply #6454 on: September 10, 2019, 01:57:50 PM »
New ice between Borden and Mackenzie King Island in the CAA

Jim Hunt

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Re: The 2019 melting season
« Reply #6455 on: September 10, 2019, 02:50:17 PM »
New ice between Borden and Mackenzie King Island in the CAA

Are you sure? It looks like "clouds" to me?

https://go.nasa.gov/2ZOkUJj
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blumenkraft

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Re: The 2019 melting season
« Reply #6456 on: September 10, 2019, 03:18:39 PM »
My bet is on clouds too.
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uniquorn

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Re: The 2019 melting season
« Reply #6457 on: September 10, 2019, 03:24:05 PM »
yup, probably clouds, polarview yesterday

SimonF92

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Re: The 2019 melting season
« Reply #6458 on: September 10, 2019, 05:06:48 PM »
I suspect if i am up against 3 veterans then the chances are that its clouds  :'(

blumenkraft

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Re: The 2019 melting season
« Reply #6459 on: September 10, 2019, 05:20:45 PM »
Nah, what's that face Simon? Being corrected on something doesn't vindicate such a face. It's all good mate. :)

And thanks a lot for the 'veteran' compliment. Very kind of you. :D
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Niall Dollard

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Re: The 2019 melting season
« Reply #6460 on: September 10, 2019, 06:38:22 PM »
This sentinel image in the pack north of Svalbard shows some freezing between the floes.

According to Nullschool temperatures in the vicinity were down between -8 C and -9 C, the day before this image was taken.


pearscot

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Re: The 2019 melting season
« Reply #6461 on: September 10, 2019, 06:39:22 PM »
What a strange ending to the melt season. For some reason I thought there were going to be at least a few more days of somewhat substantial drops, then everything just leveled off. The arctic is always full of surprises; even more so is how the huge crack above Greenland/CAB appears to have closed up (as I assume the ice shifted back).

I'm sad that both cameras I had checked daily went down this year and I was never able to see how things were looking at ground level.
pls!

uniquorn

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Re: The 2019 melting season
« Reply #6462 on: September 10, 2019, 08:25:46 PM »
This sentinel image in the pack north of Svalbard shows some freezing between the floes.
I suspect if i am up against 3 veterans then the chances are that its clouds  :'(
Thanks both for taking the time to search for early signs of refreeze :)

update on whoi itp103, a buoy currently at the entrance to amundsen gulf. Both microcats, mounted at 5m and 6m depth reporting a significant temperature increase with a smaller salinity increase today. My first thought was that the floe it may still be tethered to had melted out, but as the increase is larger at 6m perhaps it is a warm current. edit: or mixing due to eddies (suggested by sailor on the other thread)
https://www.whoi.edu/page.do?pid=163356

More details from yesterday here https://forum.arctic-sea-ice.net/index.php/topic,2417.msg227639.html#msg227639
« Last Edit: September 11, 2019, 10:38:14 AM by uniquorn »

SimonF92

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Re: The 2019 melting season
« Reply #6463 on: September 10, 2019, 09:09:30 PM »
Nah, what's that face Simon? Being corrected on something doesn't vindicate such a face. It's all good mate. :)

And thanks a lot for the 'veteran' compliment. Very kind of you. :D

Haha im only kidding Blumenkraft, my PhD basically consists of me being corrected by those more experienced and informed than me- I take each correction as a chance to learn!

blumenkraft

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Re: The 2019 melting season
« Reply #6464 on: September 10, 2019, 09:16:13 PM »
I take each correction as a chance to learn!

That's the spirit. :)
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mmghosh

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Re: The 2019 melting season
« Reply #6465 on: September 11, 2019, 02:11:40 AM »
What's the official minimum then?

Juan C. García

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Re: The 2019 melting season
« Reply #6466 on: September 11, 2019, 02:23:39 AM »
What's the official minimum then?
There is no official minimum, yet.
We have to wait until the upward (freezing) tendency if is more clear.
« Last Edit: September 11, 2019, 07:09:01 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.

Ktb

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Re: The 2019 melting season
« Reply #6467 on: September 11, 2019, 02:24:25 AM »
What's the official minimum then?

Currently, according to JAXA data, it is 4,158,349 km^2. Achieved on September 4th.
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sark

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Re: The 2019 melting season
« Reply #6468 on: September 11, 2019, 05:10:00 AM »
It's not fun to watch any more.  I don't ever wish to see the end of a lynch pin of the Northern Hemisphere's cold climate.  anyone disappointed is blissfully ignorant of what might be happening abruptly

really, my biggest fear is that the Central Arctic is *already* warmer than the surrounding land

2019 is truly terrifying
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Juan C. García

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Re: The 2019 melting season
« Reply #6469 on: September 11, 2019, 05:55:39 AM »
What's the official minimum then?

Currently, according to JAXA data, it is 4,158,349 km^2. Achieved on September 4th.
According to JAXA data, it is 4,149,896 km2. Achieved on September 10th (last value).
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.

Aluminium

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Re: The 2019 melting season
« Reply #6470 on: September 11, 2019, 07:25:27 AM »
September 6-10.

2018.

El Cid

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Re: The 2019 melting season
« Reply #6471 on: September 11, 2019, 08:05:57 AM »


really, my biggest fear is that the Central Arctic is *already* warmer than the surrounding land



Of course the Central Arctic is getting much warmer during winters than the surrounding area. It's a sea. As the ice is more and more gone, it will more and more act like a sea

El Cid

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Re: The 2019 melting season
« Reply #6472 on: September 11, 2019, 08:15:58 AM »


2019 is truly terrifying

I also don't understand this one, especially in conjunction with your graphs. I attach jan-march temperatures (NOAA ESRL) north of 70 . 2019 was the LOWEST in a decade

binntho

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Re: The 2019 melting season
« Reply #6473 on: September 11, 2019, 08:51:36 AM »


2019 is truly terrifying

I also don't understand this one, especially in conjunction with your graphs. I attach jan-march temperatures (NOAA ESRL) north of 70 . 2019 was the LOWEST in a decade

But according to this one from Zachary Labe, 2019 ranks higher than even 2016 which was by far the warmest year in the Arctic.
https://sites.uci.edu/zlabe/arctic-temperatures/



EDIT: January scored very low, dragging the January-March ranking down, but Zach's ranging graph seems to put 2019 shlightly below 2018 for the same months, equal to 2015 and well above 2012 for the same months.
« Last Edit: September 11, 2019, 09:03:21 AM by binntho »
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El Cid

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Re: The 2019 melting season
« Reply #6474 on: September 11, 2019, 09:44:02 AM »
On the one hand, sark was showing pics of jan-march, saying that 2019 is terrible. It is not, on the contrary, as I have shown - and that was the only thing that I wanted to show, nothing else.

On the other hand, I have a chart (NOAA ESRL northof 70 temps) for jan-july average temps (2019 is fifth highest, below 2006, 2016,17 and 18 - I have not yet seen the August data, that, being very warm, would probably put 2019 2nd-4th):

sark

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Re: The 2019 melting season
« Reply #6475 on: September 11, 2019, 09:55:21 AM »


2019 is truly terrifying

I also don't understand this one, especially in conjunction with your graphs. I attach jan-march temperatures (NOAA ESRL) north of 70 . 2019 was the LOWEST in a decade

good eye.  it's because the dates are 1979-1988, 2010-2019, 2016-2019.  1000mb air composite mean is the loudest signal of something stacked throughout the atmosphere.  2019 was a cold type of winter.  that's almost the scariest thing if you think about systems breaking.

The Northern Hemisphere has seen a mix of cold Arctic and warm Arctic climate regimes for almost 5 months straight.

This one is potential temperature, April-Jun.  Handful of some analogs I used to like plus the 2000's, with a look at 2010 vs 2019 at the end.
« Last Edit: September 11, 2019, 10:03:18 AM by sark »
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blumenkraft

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Re: The 2019 melting season
« Reply #6476 on: September 11, 2019, 10:03:19 AM »
September 6-10.

Looking at this, one might think there was an increase on the Atlantic side.

Big nope though. It's due to widening gaps.
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sark

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Re: The 2019 melting season
« Reply #6477 on: September 11, 2019, 10:21:27 AM »
One last chart, probably the best one to show for now, demonstrating the trend during crop planting

if you've been watching the 500mb charts in the past year you've seen it.  two prorotating lows displaced from the central Arctic, one over Novaya Zemlya, one over the Canadian Archipelago.  separated by warm barotropic air bubbles reaching the North Pole, where they tend to hold position

because the low atmospheric potential is no longer located in the central Arctic

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Freegrass

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Re: The 2019 melting season
« Reply #6478 on: September 11, 2019, 02:20:31 PM »
Latest Five Day Forecast

Wind @ Surface
2019-09-11 09:00 UTC
2019-09-16 06:00 UTC

The latest temperature animation and more can be found here.
https://forum.arctic-sea-ice.net/index.php/topic,2905.0.html
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Shared Humanity

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Re: The 2019 melting season
« Reply #6479 on: September 11, 2019, 02:44:54 PM »
September 6-10.

Looking at this, one might think there was an increase on the Atlantic side.

Big nope though. It's due to widening gaps.

This is what low pressure systems do.

harpy

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Re: The 2019 melting season
« Reply #6480 on: September 11, 2019, 04:31:57 PM »
What's the official minimum then?

Currently, according to JAXA data, it is 4,158,349 km^2. Achieved on September 4th.

The extent data is misleading, at best.  The rank matters little - what matters is the sea ice thickness and the condition of the ice in general.

Unfortunately, the sea ice extent graphs are given the most attention rather than sea ice thickness and fragmentation (and sea surface temperature).

The sea ice extent is a dubious measurement, as highly fragmented slush should not be considered "extent", but it does seem to get included.  Therefore, the "extent" of the low quality single year ice of 2019 is compared against the "extent" of the multi year ice of, say 1995 - which is incorrect - it's comparing apples to oranges.

We need to be focusing on the multi year ice, sea ice thickness  - not the "extent" data.

On that note, how's that multi-year ice doing in 2019?

blumenkraft

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Re: The 2019 melting season
« Reply #6481 on: September 11, 2019, 05:09:51 PM »
Unfortunately, by some the sea ice extent graphs are given the most attention rather than sea ice thickness and fragmentation (and sea surface temperature).

FIFY  ;)

I totally agree, the extent and area graphs are great for comparison, but you can only compare the extent and the area, and this is by far not the whole story.

Thanks to the ninjas who keep the data thread running anyway. :)

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Jim Hunt

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Re: The 2019 melting season
« Reply #6482 on: September 11, 2019, 05:14:12 PM »
We need to be focusing on the multi year ice, sea ice thickness  - not the "extent" data.

On that note, how's that multi-year ice doing in 2019?

Some "modelled" numbers via gerontocrat in the PIOMAS thread:





Recent thickness "measurements" will have to wait a while longer, but here's a map from the spring:
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sailor

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Re: The 2019 melting season
« Reply #6483 on: September 11, 2019, 05:24:20 PM »
Latest Five Day Forecast

Wind @ Surface
2019-09-11 09:00 UTC
2019-09-16 06:00 UTC

The latest temperature animation and more can be found here.
https://forum.arctic-sea-ice.net/index.php/topic,2905.0.html
With those winds the melting season might keep kicking the can for the rest of the week.
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gerontocrat

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Re: The 2019 melting season
« Reply #6484 on: September 11, 2019, 07:23:31 PM »
Unfortunately, by some the sea ice extent graphs are given the most attention rather than sea ice thickness and fragmentation (and sea surface temperature).

FIFY  ;)

I totally agree, the extent and area graphs are great for comparison, but you can only compare the extent and the area, and this is by far not the whole story.

Thanks to the ninjas who keep the data thread running anyway. :)
Don't thank us - thank NSIDC and JAXA and the satellites - while we've still got them.

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Quote
Passive microwave sensors have been routinely launched since 1987 and for many years multiple sensors have been in orbit. However, recent failures have reduced the number currently operating sensors and have significantly increased the risk of a gap in coverage in the next years.

AMSR-E failed in 2011, and the DMSP F-19 SSMIS failed in early 2016 after only two years of operation. In April 2016, the F-17 SSMIS started behaving anomalously and its data quality has been reduced. The suite of DMSP SSMI/SSMIS instruments has been the workhorse of passive microwave observations, but all currently operating (as of June 2018) SSMIS instruments (F-16, F-17, F-18) have been in orbit for at least 8.5 years, well beyond their design lifetime of three years (figure 1). The JAXA AMSR2 sensor, operating for a little over six years (as of June 2018) is the youngest passive microwave sensor, but it is now also past its design lifetime (five years). The only remaining sensor potentially ready to be launched in the near future (the DMSP F-20 SSMIS) has been cancelled.



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sark

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Re: The 2019 melting season
« Reply #6485 on: September 12, 2019, 04:36:56 AM »
high splash.
« Last Edit: September 12, 2019, 05:34:20 AM by sark »
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Freegrass

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Re: The 2019 melting season
« Reply #6486 on: September 12, 2019, 12:26:23 PM »
How many people will be trying to get the screenshot of exactly 1 million reads today? I got this beautiful number already...

Topic: The 2019 melting season  (Read 996666 times)
« Last Edit: September 12, 2019, 12:50:35 PM by Freegrass »
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Aleph_Null

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Re: The 2019 melting season
« Reply #6487 on: September 12, 2019, 01:35:13 PM »
Further illumination can be found in the Nullschool Animations thread (where, they say, Freegrass is available to all):
https://forum.arctic-sea-ice.net/index.php/topic,2905.0.html

Hindcast: 9/8 to 9/12, Forecast: 9/12 to 9/16.
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Freegrass

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Re: The 2019 melting season
« Reply #6488 on: September 12, 2019, 01:38:47 PM »
Latest update, Wind @ Surface, September 12 - 17

Last week a depression dominated the CAB for a few days and the ice dispersed. Will this high pressure system compact the ice again and weld it together in a deep freeze?
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F.Tnioli

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Re: The 2019 melting season
« Reply #6489 on: September 12, 2019, 01:43:44 PM »
...
On that note, how's that multi-year ice doing in 2019?
It's doing exceptionally well: practically all of it is in sea ice's heaven now. Gone to better world, it is. No more suffering from all the greenhouse effect, bottom melt, rains and melt ponds all over it. RIP, MYI.

NASA was kind enough to present 1984-2019 animation about it - see yourself, in which amount of ice 4+ years old is practically zero by July 2019.

Jim Hunt

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Re: The 2019 melting season
« Reply #6490 on: September 12, 2019, 01:54:55 PM »
Since cross posting seems to be the order of the day, here are some images of the sea ice east of Svalbard on September 3rd, courtesy of the Norwegian Coastguard via the "Great White Arctic Sea Ice Con" thread:





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F.Tnioli

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Re: The 2019 melting season
« Reply #6491 on: September 12, 2019, 02:00:39 PM »
Excellent photos, Jim. Thanks for posting. Always highly useful to see the ice this way - "close and personal".

P.S. and this is 100% extent right there all around, right? Yeah. Figures.

Iain

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Re: The 2019 melting season
« Reply #6492 on: September 12, 2019, 03:21:40 PM »
The extent graphs are a tease this year
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Jim Hunt

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Re: The 2019 melting season
« Reply #6493 on: September 12, 2019, 03:24:32 PM »
NASA was kind enough to present 1984-2019 animation about it

The latest NSIDC "quick look" sea ice age map:
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Jim Hunt

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Re: The 2019 melting season
« Reply #6494 on: September 12, 2019, 03:36:23 PM »
P.S. and this is 100% extent right there all around, right?

Possibly? MS Malmø seemed to get stuck for a few hours at around N 78°55' E 21°44' on September 3rd. Compare and contrast:

P.S. Added the September 4th SIC map. Presumably that movement is what caught them out?
« Last Edit: September 12, 2019, 03:44:42 PM by Jim Hunt »
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harpy

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Re: The 2019 melting season
« Reply #6495 on: September 12, 2019, 05:06:39 PM »
The extent graphs are a tease this year

I'd like to see what the multi year sea ice looks like from a photograph during this time of year for comparison.

Shared Humanity

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Re: The 2019 melting season
« Reply #6496 on: September 12, 2019, 05:48:07 PM »
NASA was kind enough to present 1984-2019 animation about it

The latest NSIDC "quick look" sea ice age map:

Many here have made the argument that the last refuge for Arctic sea ice will be along the CAA. Looking at this ice age map certainly suggests that this will be the case.

Jontenoy

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Re: The 2019 melting season
« Reply #6497 on: September 12, 2019, 07:41:29 PM »
According to Jim's graphs, ice volume has decreased from 14.9 to 4.7 * 1000 cu. km from mid 80's to now
This represents approx 0.35 * 1000  cu km change / year  at time of minimum volume. Assuming a BOE occurs  when there is 15% of the 16,000,000 max in 1980 and an average thickness of remaining ice of 1 metre, the volume at a BOE would be 2.4 cu km
Therefore , at 0.35 * 1000 loss in vol / year , we could expect a BOE in (4.7-2.4)/0.35 = 6.6 years

jdallen

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Re: The 2019 melting season
« Reply #6498 on: September 12, 2019, 09:15:20 PM »
According to Jim's graphs, ice volume has decreased from 14.9 to 4.7 * 1000 cu. km from mid 80's to now
This represents approx 0.35 * 1000  cu km change / year  at time of minimum volume. Assuming a BOE occurs  when there is 15% of the 16,000,000 max in 1980 and an average thickness of remaining ice of 1 metre, the volume at a BOE would be 2.4 cu km
Therefore , at 0.35 * 1000 loss in vol / year , we could expect a BOE in (4.7-2.4)/0.35 = 6.6 years
This makes a big assumption - that system behavior will be consistent as we reach that limit.

Based on the surprising end of season slowdown this year, I'm not sure that's safe. I'm still mulling hypotheses for what we are seeing and why the dynamics are not falling more in line with your assumptions. 

"Blue Ocean" is a boundary condition, and the retreat of the ice to where it stands now - post 2007 - suggests to me that the dynamics for the ice north of 80 are significantly different from those of the peripheral seas, which is were most significant visible changes in the Arctic have unfolded.

The ice in the CAB and along the CAA by dint of higher latitude appears less influenced by the effects of insolation and atmospheric heat.  It is also *somewhat* protected by the deeper waters of the central basin.

I  think it will require more import of oceanic heat - from the Atlantic side in particular - to push the system out of the state I think it may have settled into.

I think we may see quite a number of years like this - following the pattern of post 2012 - with the ice retreating to the high-latitude bastion we see.

We *could* see a weather driven event driving a season below 2012, but am leaning more and more to a conclusion that this would be anomalous rather than a signal of impending BoE.

I think we need a lot more data on changes in Arctic ocean enthalpy changes, as I'm thinking that and attendant changes in water column structure are what will drive us to a BoE.
This space for Rent.

oren

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Re: The 2019 melting season
« Reply #6499 on: September 12, 2019, 09:20:38 PM »
NASA was kind enough to present 1984-2019 animation about it

The latest NSIDC "quick look" sea ice age map:
A sizable fraction of the remaining older ice is currently being sucked down the Fram, after several weeks of no export. And another small part is being melted in the dwindling Beaufort arm. Regardless of this year's minimum, a lot of damage has been done, and 2020 will need to dodge another bullet.
OTOH, we can at least be thankful that the FYI from Laptev to below the pole has manage not to melt out. With different August weather this could have been open water now, after the terrible June and July.