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Shared Humanity

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Re: The 2018 melting season
« Reply #100 on: March 26, 2018, 03:50:27 AM »
If long-range modeling is correct it seems like North America and Europe/NW Russia will be quite cold continentally while heat blasts the ice pack through D10. Both Canadian and EURO are especially consistent on keeping the PV over Hudson Bay and drenching Canada/the northern US in frigid Arctic air.

Combined with the stagnant pattern over Europe and the transience over Eurasia (due to heat belching north from the Sahara/Indian), I think this primes the mid-latitudes for major cyclonic activity as we continue through April, with warmest-ever SSTAs fueling major heat plumes that will enter directly into the Bering, Chukchi, Beaufort, as well as the Atlantic front/Russian seas on a less sustained but nevertheless substantial basis.

Over the next week I anticipate we see the melt front in the Bering begin to retreat, rapidly in some areas. This will accelerate as the sun rises higher in the sky, and by 4/10 I think we could see open water into Chukchi.

Thank you for this forward looking analysis. I wonder how this will play out and whether we can expect the Atlantic and Pacific pincers of heat intrusions that plagued the Arctic for much of the winter will continue through the melting season. I also would like to thank you for your restraint and limiting your forecast to just 2 weeks.  ;)

oren

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Re: The 2018 melting season
« Reply #101 on: March 26, 2018, 04:13:16 AM »
Hi, would someone please point me to where I can find an updated current version of this ASIV  piomass graph by Jim Pettit?

https://forum.arctic-sea-ice.net/index.php/topic,119.msg63605/topicseen.html#msg63605

any heads up about usefulness background would be appreciated. thx
Check out the amazing Pettit Climate Graphs, it's in there along with lots of other stuff.
https://sites.google.com/view/pettitclimategraphs
For a discussion of all things PIOMAS, check out the very long thread on this forum.
https://forum.arctic-sea-ice.net/index.php/topic,119.0.html

bbr2314

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Re: The 2018 melting season
« Reply #102 on: March 26, 2018, 04:15:42 AM »
If long-range modeling is correct it seems like North America and Europe/NW Russia will be quite cold continentally while heat blasts the ice pack through D10. Both Canadian and EURO are especially consistent on keeping the PV over Hudson Bay and drenching Canada/the northern US in frigid Arctic air.

Combined with the stagnant pattern over Europe and the transience over Eurasia (due to heat belching north from the Sahara/Indian), I think this primes the mid-latitudes for major cyclonic activity as we continue through April, with warmest-ever SSTAs fueling major heat plumes that will enter directly into the Bering, Chukchi, Beaufort, as well as the Atlantic front/Russian seas on a less sustained but nevertheless substantial basis.

Over the next week I anticipate we see the melt front in the Bering begin to retreat, rapidly in some areas. This will accelerate as the sun rises higher in the sky, and by 4/10 I think we could see open water into Chukchi.

Thank you for this forward looking analysis. I wonder how this will play out and whether we can expect the Atlantic and Pacific pincers of heat intrusions that plagued the Arctic for much of the winter will continue through the melting season. I also would like to thank you for your restraint and limiting your forecast to just 2 weeks.  ;)

:)

Satellite imagery already shows open water in Chukchi and massive crackage spreading into Beaufort and CAB as the Bering is seemingly giving out. With additional heat expected to spike significantly by D4 and continue unabated through D10+ on modeling, perhaps Chukchi could follow even sooner than thought.

It is interesting to see the direction of the fracturing now occuring. Rolling HYCOM in 2017 you can see how the gyre transported massive amounts of Pacific/Siberian ice toward the ATL. This is now occurring in full force.

The problem 2018 is going to face vs 2017 is that the amount of heat in the Pacific sector is going to be unprecedented. This means ice formation in Beaufort and Chukchi is going to be severely truncated vs. normal and even vs. last year.

The net result should be a volume shift toward the ATL side as we see open water advance rapidly into both Chukchi and Beaufort, driven by the advancing melt front *and* by the volume export toward the Atlantic. We may see an even worse version of 2012's fake spring #s occur, where the volume push toward the ATL inflates the amount of ice in the killing zone, countering the worst-ever losses (by a decent margin) in the Pacific.

JayW

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Re: The 2018 melting season
« Reply #103 on: March 26, 2018, 12:27:41 PM »
« Last Edit: March 26, 2018, 01:03:34 PM by JayW »
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A-Team

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Re: The 2018 melting season
« Reply #104 on: March 26, 2018, 01:20:48 PM »
The four time series below look at DMI sea ice surface temperature from Jan 1st to Mar 24th from the perspective of various palettes (the original is hue-only, constant saturation and value can be discarded). The Chukchi and Svalbard regions are quite a bit warmer than the central Arctic as is the thin new ice that appeared NE of Greenland after the late February storm. The resolution of ice fractures is quite good when it shows through but Ascat remains better for feature tracking.

It appears they had limited success in removing the clouds (despite recent persistent high pressure) but nonetheless describe the product as follows:

Quote
The figure shows the mean temperature of the sea ice and the surface of the sea based on satellite observations during the past 36 hours.

The surface temperature of the ice has a great influence on the exchange of heat between the surface and the atmosphere, and thereby also the rate of increase of the sea ice volume.

Data from satellites is the primary source of information because the Arctic suffers from poor coverage in terms of the conventional observational network, which consists of drifting buoys and a number of land-based stations.

At DMI, the temperature of the surface is not measured directly. Instead, observations are used from three infrared channels on the “Advanced Very High Resolution Radiometer” (AVHRR), which is on board the MetOp-A satellite. The instrument is unable to see through clouds, however. A statistical method is therefore used to provide the missing data. The edge of the ice is shown as a black contour line. It is defined by a sea ice concentration of 15%, i.e. 15% of the surface is covered by ice.

http://polarportal.dk/en/sea-ice-and-icebergs/sea-ice-temperature.
« Last Edit: March 26, 2018, 02:52:20 PM by A-Team »

Jim Hunt

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Re: The 2018 melting season
« Reply #105 on: March 26, 2018, 02:47:50 PM »
A heads up for followers of the Norwegian young sea ICE (N-ICE2015) expedition:

http://GreatWhiteCon.info/2016/12/arctic-sea-ice-news-from-agu/

The N-ICE2015 special issue in the Journal of Geophysical Research is now complete, and has moved to a new URL:

https://agupubs.onlinelibrary.wiley.com/doi/toc/10.1002/(ISSN)2169-9291.NICE1

Several of the papers are open access.
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A-Team

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Re: The 2018 melting season
« Reply #106 on: March 26, 2018, 03:57:15 PM »
Quote
Several of the papers are open access.
Believe they all are, just search 'Researchgate + full title'

Here is the 83-day averaged temperature of the sea ice surface since Jan 1st according to DMI's Polar Portal series. The blue and white areas will have the thinnest ice as the top surface has been the warmest and will presumably be first to open up.

Indeed in the latest March 24th UH SMOS, thinness (salinity dielectric radar) correlates quite well with mean sea surface temperature (infra-red based, different satellite). However large very recent detachment of land-based ice in the Laptev and Kara cannot be expected to show up yet in averaged SST. Remarkably, the bottom of the M'Clure Strait cork is shown as whitish warm.

SMOS_Icethickness_v3.1_north_20180324.nc

Technical note: Making this summary statistic into a rolling average is moderately involved. The 83 pngs are imported and montaged, then color-separated as HSV with S and V channels discarded. The averaged image is then redisplayed with the 'union jack' indexed color table in ImageJ because of the central white and traditional blues and reds for heat (though it worked better reversed here). The grayscale palette is simultaneously recolored because it is embedded in the image. The original spectral palette with the numerical temperature scale is then put back in. Given a rolling window width, the process is then repeated on concatenated staggered layers in Gimp that are cut from ImageJ duplicates and averaged over the selected time span.
« Last Edit: March 27, 2018, 04:28:19 AM by A-Team »

romett1

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Re: The 2018 melting season
« Reply #107 on: March 26, 2018, 07:01:54 PM »

Satellite imagery already shows open water in Chukchi and massive crackage spreading into Beaufort and CAB as the Bering is seemingly giving out. With additional heat expected to spike significantly by D4 and continue unabated through D10+ on modeling, perhaps Chukchi could follow even sooner than thought.
Small update - Bering Sea ice area has dropped additional 21,000 km² in just one day (NSIDC). 2007 - 2017 average reached current level 54 days later on May 18. Looking at earth.nullschool we can see southern warm winds dominating between Thursday and Saturday. These winds could start biting Chukchi Sea again. Image: https://sites.google.com/site/arctischepinguin/home/amsr2/grf

Alexander555

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Re: The 2018 melting season
« Reply #108 on: March 26, 2018, 07:20:58 PM »
And there want be much cold before saturday.

bbr2314

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Re: The 2018 melting season
« Reply #109 on: March 26, 2018, 07:42:11 PM »
At least North American/NW Eurasian snow-water-equivalent will keep on rising...?





The heatwave expected to begin across Bering by D3-4 is now appearing increasingly severe across all guidance...

I think the below 2M T map does a good job of showing what we can expect heading deeper into spring, as well -- retention/volume building in parts of the CAB, volume pushing into ATL, and devastation across everything near the Pacific.


Lord M Vader

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Re: The 2018 melting season
« Reply #110 on: March 26, 2018, 07:47:49 PM »
While I don't think we'll see a new record low this year I think we need to watch how much heat that will be stored in Berings and Chukchi Sea this melting season. Might have a huge impact for the upcoming freezing season.

magnamentis

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Re: The 2018 melting season
« Reply #111 on: March 26, 2018, 08:01:51 PM »
While I don't think we'll see a new record low this year I think we need to watch how much heat that will be stored in Berings and Chukchi Sea this melting season. Might have a huge impact for the upcoming freezing season.

while i totally agree i strongly believe that sooner or later the ever poorer winters (du to the mentioned impact on freezing)will lead us to new lows no matter if the melting conditions will be extremely against the ice. even protected places and even though there is some positive feedback that is balancing things for a while, one day the system will have to give in to an ever more hostile (for the ice) environment all over the places which is why i (as usual) expect new record lows as being possible any year and more and more despite any locally ice friendly conditions.

as it has been each year now it will be very interesting and a lot is possible whle nothing is certain, not even a range is certain. after all we've been in for surprises again and again.
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Alexander555

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Re: The 2018 melting season
« Reply #112 on: March 26, 2018, 08:05:18 PM »
On the other side of the Bering Sea it all looks pretty cracked.

Archimid

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Re: The 2018 melting season
« Reply #113 on: March 26, 2018, 10:05:14 PM »
While I don't think we'll see a new record low this year I think we need to watch how much heat that will be stored in Berings and Chukchi Sea this melting season. Might have a huge impact for the upcoming freezing season.

Dropping this here for anyone that wants to follow that.
 
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subgeometer

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Re: The 2018 melting season
« Reply #114 on: March 26, 2018, 10:30:48 PM »
Remaining ice in the Bering Sea won't last long given the warm southerlies forecast for the next little while, its melting fast - here is the Bering Strait from 25 march on Worldview. It doesn't bode well for the Chukchi Sea.

Shared Humanity

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Re: The 2018 melting season
« Reply #115 on: March 26, 2018, 11:51:59 PM »
On the other side of the Bering Sea it all looks pretty cracked.

Ice will always appear fractured as it moves along the coast of Greenland. More interesting to me is the obvious signs of melt along the ice edge.

be cause

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Re: The 2018 melting season
« Reply #116 on: March 27, 2018, 02:30:03 AM »
Not sure about Greenland's relevance .. but Chuckchi looks like a week of southerlies will leave it a ragged mess . The ice may not wait around for melt ponds ... b.c.
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jdallen

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Re: The 2018 melting season
« Reply #117 on: March 27, 2018, 06:06:16 AM »
As I anticipated, the Bering and Chukchi are just coming apart.

It looks to be about 3-4 weeks ahead of 2017, which was far from good.
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A-Team

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Re: The 2018 melting season
« Reply #118 on: March 27, 2018, 01:47:30 PM »
Quote
Chukchi looks like a week of southerlies will leave it a ragged mess . The ice may not wait around for melt ponds
Here is the 7-day rolling average of the sea ice surface temperature, DMI polarPortal since 01 Jan 18. The Chukchi did not experience conditions conducive to thickening this winter, along with other peripheral seas with the exception of the Laptev.

The weather forecast by GFS nullschool is incredibly stable over the next 40 frames (five days), with winds sweeping the CAA icepack towards the Fram and Svalbard; a representative scene is shown below. Already, the long tongue of Kara ice intruded north of FJL is being stretched apart and the top of the M'Clure ice cork is shearing off to the west.

The Bering-Chukchi have been difficult for satellites to image, what with frequent storms sweeping in with clouds and only rare coverage by Sentinel-1AB (but central Chukchi today to Herald Island, Bering Strait on April 10th). The ice, all late FYI, hasn't formed stable features and ice movement has been fairly chaotic, with only occasional sense of ice exchange across the strait. The mp4 below shows the last 92 days.

https://www.polarview.aq/images/105_S1jpgfull/S1B_EW_GRDM_1SDH_20180326T181252_26F5_N_1.final.jpg
« Last Edit: March 27, 2018, 04:17:16 PM by A-Team »

Neven

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Re: The 2018 melting season
« Reply #119 on: March 27, 2018, 04:28:29 PM »
I've posted a blog post on the ASIB describing the situation in the Bering (and Chukchi) Sea: Bering goes extreme

Here are a couple of images/animations I've created for it:





Compare, compare, compare

oren

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Re: The 2018 melting season
« Reply #120 on: March 27, 2018, 05:17:05 PM »
I've posted a blog post on the ASIB describing the situation in the Bering (and Chukchi) Sea: Bering goes extreme
Thank you Neven. The Bering situation is truly amazing.

Lord M Vader

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Re: The 2018 melting season
« Reply #121 on: March 27, 2018, 06:15:48 PM »
Thx Neven! :) Yes, the situation in the Berings Sea is truly unprecedented but the most concerning point is, which I wrote in my earlier post, whether this will mean a new state for the Arctic sea ice or if the upcoming freezing seasons will be more "normal". The lack of sea ice in Berings Sea mean that a huge amount of solar heat will be able to be stored there during this melting season which will make it even harder for the ice to form by next season.

Back in 1996 there was also very little ice in Berings Sea at this time of year even if 2018 is far lower compared to 1996. That melting season was however one of the coldest that have been seen.

romett1

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Re: The 2018 melting season
« Reply #122 on: March 27, 2018, 06:51:55 PM »
Thank you Neven for the update. Small update - Bering Sea ice area has dropped additional 20,000 km² in just one day (NSIDC). 2007 - 2017 average reached current level 55 days later on May 20. I'm afraid that at some point I have to focus on Chukchi Sea ice area instead.
« Last Edit: March 27, 2018, 09:22:15 PM by romett1 »

Neven

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Re: The 2018 melting season
« Reply #123 on: March 27, 2018, 08:31:58 PM »
Thanks, romett1, I've posted your table on the ASIB. And you inspired me to download all the data for March since 1979, calculate the average and make a bar graph (below). Mind you, there's still five days of data left for this year's March, and so the average will go down some more.
Compare, compare, compare

Tor Bejnar

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Re: The 2018 melting season
« Reply #124 on: March 27, 2018, 08:34:16 PM »
Further to romett1's "at some point ... focus [on] Chukchi"
Current ASIG extent graph for Chukchi Sea shows the beginning of a decline.
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Neven

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Re: The 2018 melting season
« Reply #125 on: March 27, 2018, 08:37:16 PM »
PS Romett1, it says 138,839 km3 for March 26 2018 in your table. But in the data I've just downloaded from Wipneus it says 130,054 km2 for March 26 2018. I don't work with this data very often, and there are many different files on Wipneus' website, so maybe I did something wrong. I've used the nsidc_arc_nt_detail.txt file.
Compare, compare, compare

romett1

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Re: The 2018 melting season
« Reply #126 on: March 27, 2018, 09:04:12 PM »
PS Romett1, it says 138,839 km3 for March 26 2018 in your table. But in the data I've just downloaded from Wipneus it says 130,054 km2 for March 26 2018. I don't work with this data very often, and there are many different files on Wipneus' website, so maybe I did something wrong. I've used the nsidc_arc_nt_detail.txt file.
I had a quick look, this explains - excel workbook contains average daily sea ice extent and area, using 5-day trailing averages. Link is here: https://nsidc.org/arcticseaicenews/sea-ice-tools/. Also I attached pdf file - page 8 for information. So if there is huge drop in one day, it takes some days to fully appear in numbers.

Neven

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Re: The 2018 melting season
« Reply #127 on: March 27, 2018, 09:11:12 PM »
Ah yes, the 5-day average! Of course, that makes perfect sense. Thanks, romett1.
Compare, compare, compare

oren

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Re: The 2018 melting season
« Reply #128 on: March 27, 2018, 10:09:24 PM »
Further to romett1's "at some point ... focus [on] Chukchi"
Current ASIG extent graph for Chukchi Sea shows the beginning of a decline.
Area graph shows it even better.

Dharma Rupa

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Re: The 2018 melting season
« Reply #129 on: March 27, 2018, 10:34:35 PM »
Further to romett1's "at some point ... focus [on] Chukchi"
Current ASIG extent graph for Chukchi Sea shows the beginning of a decline.
Area graph shows it even better.

I'm whistling past the blueyard (graveyard).

uniquorn

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Re: The 2018 melting season
« Reply #130 on: March 28, 2018, 02:18:00 AM »
As Bones would say, "it's transpolar drift Jim, but not as we know it...."

SteveMDFP

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Re: The 2018 melting season
« Reply #131 on: March 28, 2018, 02:21:45 AM »
As Bones would say, "it's transpolar drift Jim, but not as we know it...."

"Dammit, Jim, I'm a doctor, not a polar bear!"

A-Team

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Re: The 2018 melting season
« Reply #132 on: March 28, 2018, 03:30:52 AM »
As Bones would say, "it's transpolar drift Jim, but not as we know it...."
 
Not so fast, guys:

Quote
Admiral Leonard H. McCoy, MD (?) was a Human Starfleet officer of the 23rd and 24th centuries. He was an accomplished surgeon, physician, psychologist, and exobiologist. As chief medical officer, he served aboard the USS Enterprise for twenty-seven years.

McCoy's graduation from medical school was never confirmed by Star Trek but with four years of pre-med followed by four years of medical school, McCoy would normally have received his medical degree in 2253.
A good thing to do here, since the AO and NAO give a statistically significant but nonetheless pathetic first EOFs of 23% variance for DJFM plus use dated baseline from an unfamiliar planet, is run a classifier on OSI-SAF daily ice movement pngs.

It's not so much the MSLP nor the wind that interest us this time of year but the response of the ice -- whether it fits the elusively defined (do any two depictions look the same?) concept of TransPolar Drift. (Transpolar means across the pole Wrangel to Svalbard, circumpolar means around CW zonally, neither means neither.)

You won't find 20% of individual DJFM days remotely consistent with classical TPD. But the real bottom line is the time integral of daily drift -- and near total lack of TPD over the last twelve months -- which I have posted 30-40 times up-forum to no apparent effect.

http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2018&month=02&day=26&prod=LR-Drift&area=NH&size=100%25
« Last Edit: March 28, 2018, 12:35:19 PM by A-Team »

uniquorn

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Re: The 2018 melting season
« Reply #133 on: March 28, 2018, 01:36:05 PM »
Quote
which I have posted 30-40 times up-forum to no apparent effect

I couldn't resist a bit of humour and gained some ST lore.

Nonetheless, looking at the ascat sea ice roughness 01 Jan to 25 Mar 2018 above, accepting that the ice movement is largely rotational clockwise, there is a discernible export across the whole Atlantic front while losing ice cover on the Pacific side.
Largely wind driven recently and probably not what Bones implied.

FishOutofWater

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Re: The 2018 melting season
« Reply #134 on: March 28, 2018, 03:49:42 PM »
Was the transpolar drift ever anything but a general tendency for ice to pile up on the north shores of Ellesmere Island and Greenland and to flow out the west side of the Fram strait. Was it every anything but a situation where most rubber duckie would eventually work their way from the Bering strait to the Fram strait. Was it ever anything but a general observation that ice is thicker on the Canadian side of the Arctic than the Siberian side?

Or has something changed?

The repeated melt outs of the last decade in the Beaufort and Chukchi seas have surely changed the dynamics of ice motion because thick ice that used to rotate for 5 years or more in the Beaufort gyre melts out now. Ice goes to the Beaufort sea to die now. It doesn't live to a ripe old age anymore. The loss of thick ice in the Beuafort gyre has changed the dynamics of flow in the Arctic ocean. Thinner ice moves faster. A number of journal articles discuss the effects of ice thickness and open water on the motion of ice and water in the Arctic. Numerical models of ice dynamics predict increasing flow through the CAA. So we know there are changes in flow and that change will continue as ice thins in the CAA.

But based on what has been reported about the variability in the Arctic oscillation and other indicators of atmospheric dynamics in the Arctic, I doubt that the "transpolar drift" was ever anything but a very general simplification based on the observation that ice piles up on the north shores of Greenland and the CAA.

It's easy to track the train of thick ice that was in the CAA that has rotated around the displaced Beaufort gyre this fall and winter on the JAXA RGB map. Tracking other features is not so easy because of zones of compression, extension and shear. The ice pack is constantly deforming.

uniquorn

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Re: The 2018 melting season
« Reply #135 on: March 28, 2018, 04:44:24 PM »
Clearer weather north of Greenland allows a decent view of the thinner ice that remains of the storm damage and the ice front expanding drifting into the Fram Strait. Mar25-28.

Worldview brightness temperature band 15, night squashed palette
« Last Edit: March 29, 2018, 01:12:11 AM by uniquorn »

Tor Bejnar

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Re: The 2018 melting season
« Reply #136 on: March 28, 2018, 06:28:52 PM »
The O-Buoy Project shows a little evidence of historical trans-polar drift.
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romett1

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Re: The 2018 melting season
« Reply #137 on: March 28, 2018, 06:57:12 PM »
Bering Sea ice area (5-day trailing average) has dropped additional 13,000 km² (NSIDC). 2007 - 2017 average reached current level 56 days later on May 22. As southerly winds are dominating between March 29 and April 1, there should be further declines (on excel sheet) starting somewhere after March 30. Looking at April 2 on earth.nullschool we can still see mild temperatures over Bering Sea and Chukchi Sea.

Shared Humanity

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Re: The 2018 melting season
« Reply #138 on: March 29, 2018, 01:01:32 AM »
Clearer weather north of Greenland allows a decent view of the thinner ice that remains of the storm damage and the ice front expanding into the Fram Strait. Mar25-28.

Worldview brightness temperature band 15, night squashed palette

Expanding is not how it should be described. The ice is drifting into Fram Strait where it will travel to its doom.

uniquorn

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Re: The 2018 melting season
« Reply #139 on: March 29, 2018, 01:17:53 AM »
Thank you for that correction Shared Humanity. I've edited the original.

dmi 80N temperature chart:



be cause

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Re: The 2018 melting season
« Reply #140 on: March 29, 2018, 01:29:03 AM »
Hi Shared Humanity ; surely it is expanding .. the front is advancing every day .. the ice behind it is fracturing and freezing . There are numerous such fracture zones atm .. those between Greenland and the pole are particularly active . .
I am feeling the chill of the trans polar drift here in N. Ireland . I seem unable to return to sender .. b.c.
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Re: The 2018 melting season
« Reply #141 on: March 29, 2018, 02:06:13 AM »
Is it possible the slight difference in extent, showing on NSIDC 'Charctic', between 2018 and 2017 (lowest for this date, and maybe 2006), the main difference is just the stuff peripheral to the Arctic Ocean around Novaya Zemla?
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/


FredBear

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Re: The 2018 melting season
« Reply #142 on: March 29, 2018, 05:09:17 AM »
The transpolar drift was the name given to the general direction taken by ice in the past - it took the Fram nearly three years to go with the flow, (& miss the pole!) from 1893 - but the Tara only took about 2 years (2006-8). Recently the ice seems to have lost its drift   .    .    we have a different Arctic for these seasons?

Sterks

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Re: The 2018 melting season
« Reply #143 on: March 29, 2018, 11:38:39 AM »
Fram export was especially vigorous in 2007 so I am not sure if that 2006-2008 example compares well with more recent seasons.
In my opinion, it is more than probable a long-term trend of the ice becoming more mobile, but the overall drift (in pattern and intensity) for each winter seems highly variable.

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Re: The 2018 melting season
« Reply #144 on: March 29, 2018, 12:35:34 PM »
The ECMWF forecast is very interesting right now. The high pressure area west of Alaska that is causing the southerlies which push the ice northwards, is about to intensify and then move into the Central Arctic five days from now, where it is projected to reach 1055 hPa. Now, that's high. The sun is probably too low for any solar radiation to make an impact, but it's still impressive. It might also start pulling the ice away from the Siberian coast. And then, of course, there's the transport towards Fram.

Here's the 6-day forecast below (from Tropical Tidbits). The template I use for this, is for the melting season proper, which is why the North Pacific isn't shown:
Compare, compare, compare

Niall Dollard

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Re: The 2018 melting season
« Reply #145 on: March 29, 2018, 12:46:33 PM »
The ECMWF forecast is very interesting right now. The high pressure area west of Alaska that is causing the southerlies which push the ice northwards, is about to intensify and then move into the Central Arctic five days from now, where it is projected to reach 1055 hPa. Now, that's high. The sun is probably too low for any solar radiation to make an impact, but it's still impressive. It might also start pulling the ice away from the Siberian coast.

Whatever about the Siberian coasts, it could also promote more lift off in the eastern Beaufort (which has already begun !) 

Neven

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Re: The 2018 melting season
« Reply #146 on: March 29, 2018, 01:19:16 PM »
Whatever about the Siberian coasts, it could also promote more lift off in the eastern Beaufort (which has already begun !)

Yes, that too.  :)

I haven't been looking at satellite images lately, but do I see algal blooming below the clouds in the Bering Sea?

Compare, compare, compare

uniquorn

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Re: The 2018 melting season
« Reply #147 on: March 29, 2018, 01:48:40 PM »
Whatever about the Siberian coasts, it could also promote more lift off in the eastern Beaufort (which has already begun !)
I was just looking at that. Beaufort is mobile despite low temperature anomalies. It will be interesting to see what happens with warmer weather forecast.
Mar18-28

Worldview brightness temperature,band15,night,squashed palette

A-Team

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Re: The 2018 melting season
« Reply #148 on: March 29, 2018, 05:22:21 PM »
The winds continue to blow south across the Barents Line (rather than zonally CW in accordance with a persistent polar high ringed by lows), pushing the ice in this sector forward at 5 km/day along a 1000 km line up towards Svalbard and FJL; overall ice motion is very complex because wind stress is very unevenly applied and the icepack is not frozen solid enough to move as a rigid body.

Since the surface water is so warm here per Mercator Ocean, the advected ice will largely melt in situ, not even surviving to melt as export into the Barents proper. This type of 'export' contrasts with the Fram and under-sea moorings there that can measure ice volume prior to melt.

The long dark tongue of Kara ice that began intruding into the Arctic in late November has disintegrated almost overnight, even at the resolution of Ascat (which is 2x better than the Jaxa up-forum). Watch the last 2-3 frames of the mp4 to see this unfolding; GFS wind forecasts suggests this will continue for several more days (though the overall wind pattern is chaotic).

That major northward flow of ice does not remotely fit into the TransPolar Drift paradigm -- which is not a casual figure of speech but often included as a figure in peer-reviewed climate science journals. It is a hang-over from ENSO-NAO teleconnection theory with little explanatory power for Arctic Ocean ice movement over the last year.

We have seen 29 straight days of cloud street on WorldView VIIRS. They are also visible on Sentinel-1B even though the active radar there normally sees through clouds; these may be ice or turbulence has entrained salinity.
« Last Edit: March 29, 2018, 09:11:32 PM by A-Team »

FishOutofWater

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Re: The 2018 melting season
« Reply #149 on: March 29, 2018, 05:38:59 PM »
Last year there was a larger than normal amount of cyclonic flow in the Arctic. From 1988 to 1995 the flow was very cyclonic over the Arctic ocean. Cyclonic flow is incompatible with "transpolar drift".

There is nothing wrong with the observations of the ships drifting towards the Fram strait, but we shouldn't cherry pick those 2 events to represent "how things used to be." Atmospheric and oceanic flow patterns in the Arctic were very different in the periods 1988-1995 and 1996-2005.

There are natural "cycles" in the Arctic oscillation and there are the effects of climate change and reduced ice volume and thickness on top of the natural oscillations. The lack of transpolar drift in a predominantly cyclonic year, however, is to be expected. The O - buoy data reflect the complexity of what actually happens in the Arctic. The concept of transpolar drift is a gross simplification.