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Author Topic: The 2017/2018 freezing season  (Read 9226 times)

weatherdude88

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Re: The 2017 freezing season
« Reply #50 on: August 29, 2017, 01:52:04 PM »
NSIDC northern hemisphere sea ice extent had another uptick today. we are now 102000 Kilometers squared above 8.25.2017. 8.28.2017 is now the highest value in the last 5 days.

Sterks

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Re: The 2017 freezing season
« Reply #51 on: August 30, 2017, 09:11:39 AM »
Significant cooling and snowing over the CAB toward the Beaufort side in the next days. The snow models of ESRL and GFS:
https://www.esrl.noaa.gov/psd/forecasts/seaice/
Not sure how to bring these animations here out of the noaa page.
The winds seem to keep pushing the ice from the South at Laptev and ESS from this model.

Ned W

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Re: The 2017 freezing season
« Reply #52 on: August 30, 2017, 11:53:38 AM »
Surprise! (or not)  -- it turns out that Aug 26 was not the JAXA extent minimum.  A pretty normal drop yesterday. 

Shared Humanity

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Re: The 2017 freezing season
« Reply #53 on: August 30, 2017, 07:07:12 PM »
Surprise! (or not)  -- it turns out that Aug 26 was not the JAXA extent minimum.  A pretty normal drop yesterday.

Not....at least not for me.

Brigantine

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Re: The 2017 freezing season
« Reply #54 on: September 04, 2017, 11:42:00 PM »
The re-freeze has now reached CIS maps.

Peabody bay as of 2017-09-04 18Z has 1/10 new ice alongside the 2/10 - 9/10 of one-summer-old ice. (Eureka - WIS36CT)

BTW, is this necessarily the result of freezing? Or is it possibly snow?

Ned W

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Re: The 2017 freezing season
« Reply #55 on: September 05, 2017, 02:50:57 PM »
That's three consecutive days of increasing extent in JAXA, since 1 September.  There are often several days of "false start" like this, but 2017 is tied with 2004 for the earliest three-day period of consecutive increases.  2015 had a similar run of three days starting a day later.

Tealight

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Re: The 2017 freezing season
« Reply #56 on: September 06, 2017, 11:24:48 AM »
By now over 95% of this years solar energy was either absorbed or reflected by the Arctic Ocean and I can finally post my refreeze-forecast.

When thinking about refreezing, the lowest sea minimum should also correlate with a low sea ice area / extent during the freezing season because a lot of open water has to refreeze. But the September minimum isn't quite as good as my AWP anomaly calculation, which considers absorbed heat by the oceans as well. For the last 11 years I compared the sea ice area minimum, the sea ice extent minimum and the cumulative AWP anomaly against the average sea ice area and extent anomaly during the October-December refreeze.

An Overview about individual years can be found here:
https://sites.google.com/site/cryospherecomputing/warming-potential


The AWP correlation is negative, because a higher solar energy absorption results in a slower refreeze, hence a negative area anomaly. See the attached graph for all 11 years.(the zero line is not the same for both axis and the secondary axis is inverted due to the negative correlation)

Correlation with Oct-Dec Extent anomaly
Minimum Area   0.779236221
Minimum Extent   0.699103822
Cumu AWP anomaly   -0.84296024
   
Correlation with Oct-Dec Area anomaly
Minimum Area   0.748245297
Minimum Extent   0.637113296
Cumu AWP anomaly   -0.784477392

Surprisingly for me all forecast methods correlate better with the sea ice extent anomaly and not the sea ice area anomaly. The ranking however always stays the same. The best is my cumulative AWP anomaly, followed by the sea ice area minimum and least skillful is the sea ice extent minimum.

For 2017 with a "cumu AWP" of +15.8 MJ/m2 we should expect an average extent anomaly of -0.22 million km2

Edit: without 2009 the AWP anomaly would correlate to 94% with sea ice extent and 93% with sea ice area
« Last Edit: September 06, 2017, 11:33:11 AM by Tealight »

Niall Dollard

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Re: The 2017 freezing season
« Reply #57 on: September 06, 2017, 11:13:20 PM »
The re-freeze has now reached CIS maps.


Yes. Today's map shows an area of pink (new ice) in the Kane Basin.

My interest today though switched to the Nansen Sound above Eureka, Ellesmere Island.

Eosdis Worldview image shows a lot of what looks like new ice in the sound (esp compared with previous clear image on 4th Sep).

However Sentinel does provide a nice close up of Nansen Sound on the 4th with some new ice.

Niall Dollard

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Re: The 2017 freezing season
« Reply #58 on: September 10, 2017, 12:06:43 PM »
An animated GIF on the thickening new ice in Nansen Sound, Ellesmere Island 3rd to 9th Sept.

2phil4u

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Re: The 2017 freezing season
« Reply #59 on: September 10, 2017, 04:10:10 PM »
By now over 95% of this years solar energy was either absorbed or reflected by the Arctic Ocean and I can finally post my refreeze-forecast.

When thinking about refreezing, the lowest sea minimum should also correlate with a low sea ice area / extent during the freezing season because a lot of open water has to refreeze. But the September minimum isn't quite as good as my AWP anomaly calculation, which considers absorbed heat by the oceans as well. For the last 11 years I compared the sea ice area minimum, the sea ice extent minimum and the cumulative AWP anomaly against the average sea ice area and extent anomaly during the October-December refreeze.

An Overview about individual years can be found here:
https://sites.google.com/site/cryospherecomputing/warming-potential


The AWP correlation is negative, because a higher solar energy absorption results in a slower refreeze, hence a negative area anomaly. See the attached graph for all 11 years.(the zero line is not the same for both axis and the secondary axis is inverted due to the negative correlation)

Correlation with Oct-Dec Extent anomaly
Minimum Area   0.779236221
Minimum Extent   0.699103822
Cumu AWP anomaly   -0.84296024
   
Correlation with Oct-Dec Area anomaly
Minimum Area   0.748245297
Minimum Extent   0.637113296
Cumu AWP anomaly   -0.784477392

Surprisingly for me all forecast methods correlate better with the sea ice extent anomaly and not the sea ice area anomaly. The ranking however always stays the same. The best is my cumulative AWP anomaly, followed by the sea ice area minimum and least skillful is the sea ice extent minimum.

For 2017 with a "cumu AWP" of +15.8 MJ/m2 we should expect an average extent anomaly of -0.22 million km2

Edit: without 2009 the AWP anomaly would correlate to 94% with sea ice extent and 93% with sea ice area

Do you talk about the difference of the anomaly now and the anomaly later ?
So if now for example we have -1 Mio, a Dezember of -1.2 Mio  is 200k change ?
Why dont you take the invert instead of getting a negative correlation.
In general i think in very low ice years we see a stronger refreeze, so if we have 3 Mio Minimum, in November we  surely have less then with a 5 Mio Minimum, but not 2 Mio less i guess.
Maybe you can find a formula that fits optimal for the years,you can also change the Nov values a bit if you think weather was unusal.
« Last Edit: September 10, 2017, 04:29:07 PM by 2phil4u »

Pavel

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Re: The 2017 freezing season
« Reply #60 on: September 10, 2017, 05:04:22 PM »
2017 looks warmer in the Laptev\ESS\Chuckchi than 2016. It's colder in the Kara\Barents but this side hit by fall\winter warm cyclones and freezing momentum is weak there. In general one should expect mild fall and sluggish ice growth

Pavel

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Re: The 2017 freezing season
« Reply #61 on: September 11, 2017, 07:30:58 PM »
Comparing some clear Wolrdview views from 30 of July and today we see the surface refreeze have taked place north of Greenland. Also there was significant ice retreat near Svalbard where it was 4-metres thick ice at the start of melting

Brigantine

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Re: The 2017 freezing season
« Reply #62 on: September 13, 2017, 10:49:05 PM »
My interest today though switched to the Nansen Sound above Eureka, Ellesmere Island.

Wise choice. That's the only place anywhere showing grey ice floes forming on the weekly CIS maps released today. (Eastern Arctic, areas V and EE have up to 3/10 of grey ice as 20-100m floes within the pink ice)

Niall Dollard

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Re: The 2017 freezing season
« Reply #63 on: September 14, 2017, 07:41:40 PM »
Ah yes Brigantine, Ellesmere and north Greenland the last cold bastion of the northern Hemisphere.  :)

There have been some nice clear images this September and looking back through Worldview on 10th September, it looks a lot more frozen than on the same date last year. (images attached, one year apart).  A little better than the other years shown on Worldview but I expect it's not that much different to what climatology would suggest, but maybe snow is a little more deep and extensive.

My hope for this freezing season is that the Ellesmere/Greenland cold will spread/extend readily across the CAA. The tongue in the eastern Beaufort should help the ice to develop in that section and help close the Beaufort Bite.

The western Beaufort and Chukchi will be problematic due to high SSTs and I expect slow extension into these seas.

I'd hope there is early/extensive/deep snowfall across the top of Russia. Snow and associated low autumnal temps could help the pack extend readily through the Laptev/Kara and ESS. But as it stands there is a considerable gap between the ice edge and Russia. I think if we do not see a good extension of a solid pack covering much of the Arctic Basin quite soon, the DMI N80 temps will struggle once again to reach the ERA40 (1958-2002) mean over the winter half of the year (like last year). Already the drift away from the old "norm" has begun . http://ocean.dmi.dk/arctic/meant80n.uk.php

The SSTs in the Barents perplexes me. Especially in the northern part. Typically the last few years, the SSTs in the Barents have been very high. Recent months they are lower. But I doubt if this will have much significant effect on ice extension until maybe late this Winter/Spring as no doubt there will be many autumn/winter Atlantic storms to come preventing ice extension.

Having said all this, it can and probably will all go pear shaped and we will end up next May with yet another thin/weak pack. It looks like we will still be scratching around hanging on until the next big El Nino year wreaks havoc. Probably needs a miracle at this stage or somehow a plateauing of CO2 emissions.


Brigantine

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Re: The 2017 freezing season
« Reply #64 on: September 15, 2017, 09:33:34 AM »
A reasonable amount of pink ice forming in the Chukchi sea (per CIS).

At 78N, only where the surface waters are kept chilled by melting open drift ice from last winter, and even then it's patchy. (for reference: at 78N, 135W - 150W)

Compared with the same date 2014 and 2015, the re-freeze this year is a bit further advanced.
(and surviving ice much sparser)

Though by this date (+1 day) in 2016 at the same latitude, the refreeze had already developed even further - comprehensive new ice (9+/10) in areas without more than a trace of surviving ice, and around open drifts of surviving ice the re-freeze was already at the stage that Nansen Sound is this year (on 2017-09-11).
« Last Edit: September 15, 2017, 09:40:21 AM by Brigantine »

Niall Dollard

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Re: The 2017 freezing season
« Reply #65 on: September 15, 2017, 06:19:03 PM »
Yes on many of the CIS regional maps Chukchi/Beaufort/Northern parts of CAA, there are many areas now coloured pink (new ice).

It has been cold. For the week ending Sept 11th mean temp at Eureka was -8.8 C (norm -4.3) and Resolute -3.4 C (norm -2.8 ).

Thomas Barlow

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Re: The 2017/2018 freezing season
« Reply #66 on: September 16, 2017, 10:43:58 PM »
Judging by this, the Arctic Ocean itself (ignoring all peripherals such as CAA and Fram, etc., and thick ice crushed against land - "bits of ice stuck to land", as Wadhams puts it, re. a future 'Blue Ocean Event') looks like the overall ocean itself (ignoring fjords and coastal build-up) is about as bad a state as it gets for volume, maybe worst, at the start of freezing season.

Niall Dollard

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Re: The 2017/2018 freezing season
« Reply #67 on: September 16, 2017, 11:53:31 PM »
Judging how, by eye, Thomas ? As to pronounce which is worst, I wouldn't wish to comment as brain/eye can be deceptive.

Pavel

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Re: The 2017/2018 freezing season
« Reply #68 on: September 16, 2017, 11:53:58 PM »
Very much of survived FY ice. The ice formed last October in the Laptev sea now above the Pole. Another issue is that export goes mostly to the Beaufort but not Fram strait. In general the start of refreeze in terms of accumulated FDD is similar with 2016. It will take a long while when the periphery seas start to freeze up. The question should be whether the  freezing season will be very mild or extremely mild

Thomas Barlow

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Re: The 2017/2018 freezing season
« Reply #69 on: September 17, 2017, 12:37:53 AM »
Judging how, by eye, Thomas ? As to pronounce which is worst, I wouldn't wish to comment as brain/eye can be deceptive.
No, not really. It's pretty clear to a well trained eye. ;-)

Pavel

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Re: The 2017/2018 freezing season
« Reply #70 on: September 18, 2017, 06:48:30 PM »
These two DMI graphs of north of 80 latitude temps and Greenland ice sheet mass budget pretty show the mild and snowy story continues. Could be a pattern for the whole season

Alec aka Daffy Duck

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Re: The 2017/2018 freezing season
« Reply #71 on: September 19, 2017, 01:06:14 AM »

Daniel B.

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Re: The 2017/2018 freezing season
« Reply #72 on: September 19, 2017, 03:28:08 PM »
These two DMI graphs of north of 80 latitude temps and Greenland ice sheet mass budget pretty show the mild and snowy story continues. Could be a pattern for the whole season

Already ahead of the pace set in 2016/17.

Shared Humanity

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Re: The 2017/2018 freezing season
« Reply #73 on: September 19, 2017, 03:57:12 PM »
These two DMI graphs of north of 80 latitude temps and Greenland ice sheet mass budget pretty show the mild and snowy story continues. Could be a pattern for the whole season

Already ahead of the pace set in 2016/17.

Our climate is changing. We should expect to be surprised by new persistent features of this changing climate. With more moisture in our atmosphere, increased snowfall would seem to be a logical result.

Shared Humanity

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Re: The 2017/2018 freezing season
« Reply #74 on: September 19, 2017, 04:02:23 PM »
These two DMI graphs of north of 80 latitude temps and Greenland ice sheet mass budget pretty show the mild and snowy story continues. Could be a pattern for the whole season

A snowier Greenland would suggest a snowier Arctic Ocean as well, at least on the Atlantic side. This was a point of heated discussion during the just completed melt season. If the Atlantic cyclone cannon fires up like it did last winter, I would think that more snow would fall. Could this heavier snowfall explain the conditions we find on the Atlantic side of the Arctic where the ice was remarkably resistant to melt?

Daniel B.

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Re: The 2017/2018 freezing season
« Reply #75 on: September 19, 2017, 05:14:43 PM »
These two DMI graphs of north of 80 latitude temps and Greenland ice sheet mass budget pretty show the mild and snowy story continues. Could be a pattern for the whole season

Already ahead of the pace set in 2016/17.

Our climate is changing. We should expect to be surprised by new persistent features of this changing climate. With more moisture in our atmosphere, increased snowfall would seem to be a logical result.

That would be true only for those locations consistently below freezing.  Otherwise, we would expect more of the snow to fall as rain.

Dharma Rupa

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Re: The 2017/2018 freezing season
« Reply #76 on: September 19, 2017, 05:21:05 PM »
That would be true only for those locations consistently below freezing.  Otherwise, we would expect more of the snow to fall as rain.
I think you can use the northward march of the permafrost and several species of trees as a pretty good proxy for the rain/snow line.  Still far enough south that I think we can expect plenty of snow this winter, but maybe not a decade from now.


Pavel

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Re: The 2017/2018 freezing season
« Reply #77 on: September 19, 2017, 10:38:33 PM »
The Garlic Press still in action. Winds may change direction backward for some days but then it should resume. Ice was squeezing through the strait for the entire September not even depended on winds very much

Brigantine

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Re: The 2017/2018 freezing season
« Reply #78 on: September 20, 2017, 12:12:01 AM »
First sight on CIS daily charts of grey ice in the Eastern Arctic - in the Parry Channel around 102W.
(Approaches to Resolute 2019-09-19, areas D, G and M)

Also the first time in the Chukchi Sea that grey ice is forming in areas without surviving drift ice.
(Area D)

The new ice in Nares Strait and the Beaufort Tongue OTOH is struggling just to survive.

Alec aka Daffy Duck

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Re: The 2017/2018 freezing season
« Reply #79 on: September 20, 2017, 10:37:32 PM »
Hopefully this image comparing SST for Kara and Barents 2016 v 2017 will work:




<Alec, if you highlight the link, and then click on the img/image button (middle row, second from left, next to small f/flash button), the links will then show up as images. Or you can click 'attachment and other options' below the comment box and upload them to the Forum server directly; N.>
« Last Edit: Today at 03:51:21 PM by Neven »

Pavel

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Re: The 2017/2018 freezing season
« Reply #80 on: September 20, 2017, 11:32:51 PM »
Hopefully this image comparing SST for Kara and Barents 2016 v 2017 will work:
https://s19.postimg.org/7f2nx4c9f/aab_sst_2016_2017.png
https://postimg.org/image/k6gu3mm1b/
Interesting that Hycom shows very warm currents north of Svalbard resume. North of Kara almost the only area relatively cold in terms o SSTs but it most likely should be hit by warm storms, it's not the area to build meters of ice. The Laptev sea that is the factory of ice for CAB looks warmer, ESS\Chukchi\Beaufort are terrible. The Hudson Bay and Sea of Okhotsk are overheated and promising low extent for the entire freezing season. Most likely we'll expierence the negative phase of the Arctic Oscillation