Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2017/2018 freezing season  (Read 202568 times)

Apocalypse4Real

  • ASIF Citizen
  • Posts: 360
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1350 on: March 11, 2018, 09:22:39 PM »
Pmt,

Alaskan lightning detection depicted strikes over the ice at 79N two years ago.

A4R

Pmt111500

  • ASIF Upper Class
  • Posts: 1324
    • View Profile
  • Liked: 4
  • Likes Given: 2
Re: The 2017/2018 freezing season
« Reply #1351 on: March 11, 2018, 09:56:50 PM »
Pmt,

Alaskan lightning detection depicted strikes over the ice at 79N two years ago.

A4R

Didn't know of those, thanks, 69,5N was of course in Lapland and in summer. Hopefully many places of permafrost do not dry up after melting, lightning strikes might start some vast wildfires.
A quantity relates to a quantum like camel's back relates to camel's _______ ? (back, vertebra, vertebral tendon, spinal disc, paralysis)

cesium62

  • ASIF Citizen
  • Posts: 268
    • View Profile
  • Liked: 3
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1352 on: March 12, 2018, 12:19:28 AM »
Slater's Projected Probabilistic Sea Ice Extent looks a bit interesting today.  It's projecting a hunk of ice in the southern Bering Sea with open waters further north.  Is that plausible, or just an interesting algorithmic anomaly?

charles_oil

  • ASIF Citizen
  • Posts: 232
    • View Profile
  • Liked: 0
  • Likes Given: 5
Re: The 2017/2018 freezing season
« Reply #1353 on: March 12, 2018, 12:43:44 AM »
Chartic (current graph) shows very little ice there already so I guess there wont be much in late April.

Tealight

  • ASIF Citizen
  • Posts: 295
    • View Profile
    • CryosphereComputing
  • Liked: 4
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1354 on: March 12, 2018, 12:50:33 AM »
Slater's Projected Probabilistic Sea Ice Extent looks a bit interesting today.  It's projecting a hunk of ice in the southern Bering Sea with open waters further north.  Is that plausible, or just an interesting algorithmic anomaly?

No it's not plausible and a result of the algorithm, specifically the northern ice edge this year and the fact that these areas can still freeze over. It's only a melt algorithm and it doesn't model freezing well.

In the northern Bering Sea and north of Svalbard the ocean is sometimes ice-free and has frozen over during the next few weeks. So if on average sea ice concentration increased by 20-30% the refreeze alone pushes the area above the 15% extent threshold. (0%+20%=20%)

This year the sea ice edge is much further north than ever before. There the concentration was always 90-100%. It could never increase much. With a concentration change of 10% added to existing 0% the maximum concentration is 10%, hence ice-free.

uniquorn

  • ASIF Citizen
  • Posts: 207
    • View Profile
  • Liked: 35
  • Likes Given: 7
Re: The 2017/2018 freezing season
« Reply #1355 on: March 12, 2018, 10:52:49 AM »
A nice arch has formed in the Kane Basin (Nares).

Tor Bejnar

  • ASIF Upper Class
  • Posts: 1836
    • View Profile
  • Liked: 17
  • Likes Given: 6
Re: The 2017/2018 freezing season
« Reply #1356 on: March 12, 2018, 02:55:19 PM »
The Kane Basin arch took its current form on March 1st.  (Nares Poll thread GIF)
Arctic ice is healthy for children and other living things.

A-Team

  • ASIF Upper Class
  • Posts: 2214
    • View Profile
  • Liked: 103
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1357 on: March 12, 2018, 07:23:44 PM »
Quote
In order to be able to forecast the weather and the properties of the sea ice using numerical models, it is crucial that the surface temperature is determined correctly.

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. This integrated Ice and Sea surface temperature product is part of the EU satellite monitoring program for marine environment, Copernicus CMEMS. The product is based on the OSI-205 product from EUMETSAT Ocean and Sea Ice Satellite Application Facility (EUMETSAT, OSI SAF). The figure shows the latest 36-hour sliding mean temperature of the ice- and ocean surface.

http://polarportal.dk/en/sea-ice-and-icebergs/sea-ice-temperature/

That's right, 2m and 950 mB air temperatures per se are of lesser relevance to winter ice thickening or spring melt ponds than that of the upper ice surface which provides the temperature gradient through the ice (linear at equilibrium in slab heat equation clamped to -1.81ºC bottom water) and so the rate of heat conductance.

Why use observationally unsupported modeled meteorological proxies when you have physical IR temperatures data from satellite where and when they're wanted?

The third image uses ice temperature as an over-tint of Ascat ice roughness/thickness.

The bottom slide show illustrates how ice motion can be tracked via delauney triangulation deformation. Ice transport -- either to intra-basin locales with warmer water (eg Chukchi) or out into the North Atlantic, Barents, Bering or Baffin Bay -- is an important adjunct to in situ thermodynamic melting.

Technical notes: DMI did some nice work here assembling their rolling 36 hour frames from orbital swaths sometimes obscured by weather. The final unsquashed spectral color palette, lost row of date pixels, inability to download animations, omission of scale and lack of ftp server were not the best choices for data dissemination.

The palette fortunately proved to be hue-only HSL, meaning the saturation and luminance channels were empty, allowing recovery of grayscale and re-paletting after RGB decomposition. Ascat needed 106.68% resizing to co-register.

There are huge opportunities for image segmentation (into ice classes) if three independent channels of daily ice imagery can be brought into a single colored animation, as there is different information in each wavelength. Here adding a visible channel is not practical over the Arctic Basin because of persistent clouds. However it may be feasible to add a deformation parameter channel (~viscosity) by analyzing ice motion.
« Last Edit: March 12, 2018, 10:53:14 PM by A-Team »

uniquorn

  • ASIF Citizen
  • Posts: 207
    • View Profile
  • Liked: 35
  • Likes Given: 7
Re: The 2017/2018 freezing season
« Reply #1358 on: March 12, 2018, 07:54:32 PM »
The Kane Basin arch took its current form on March 1st.  (Nares Poll thread GIF)
thank you Tor. Completely missed that.

A-Team

  • ASIF Upper Class
  • Posts: 2214
    • View Profile
  • Liked: 103
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1359 on: March 12, 2018, 09:31:45 PM »
Quote
Kane Basin arch took its current form on March 1st.
The arch can also be seen kicking in on Ascat (green arrow) though the resolution is not nearly as clear as in Niall's animation of DMI Greenland. Ice continues to exit the NW Passage (magenta arrow) despite the blockage at Lowther Island (red arrow).

The last week in ice have seen winds induce a lift-off of the ice pack (yellow arrows) from Nares to Bank Island, with its cork to the east popping up twice (orange arrow). The current continues to bring ice in from the west side of upper Nares (orange arrow) whereas the Lincoln Sea quiet zone stays unmoved (purple arrow). About half the new ice from the February storm polynya is exiting the Fram (cyan arrow).

This coming week will see strong winds further deforming the Beaufort stringer to the northwest, accompanied by several days of export out the Bering Strait, to melt oblivion. On the Barents side, there will be considerable ice export through gaps between FJL and the Siberian mainland and continuing strong westward movement of Kara Sea ice south of FJL and Svalbard.

It's fascinating that Arctic ice moves so much every day that changes be can seen even from a low resolution product like Ascat prior to enhancement. Matching Ascat with a Google Earth display, this is tantamount to looking down at the North Pole from a spaceship 10,780 km above the earth, whereas the satellite bearing the scatterometer flies much lower (~837 km) in near-polar orbit.

Note too when the Ascat animations are set to play at 140 ms per day (or one second for a week of data), that week actually occupied 60*60*24*7 = 604800 seconds. (I used much higher time compression in Jakobshavn and Petermann glacier animations.)

Technical note: Google uses the ellipsoid of revolution WGS84 as datum and 'simple cylindrical' (plate carrée) as projection whereas Ascat is in polar stereographic. The OCI-SAf ice motion vectors are over two days; the pair shown are 2018 03 07-09 and 2018 03 09-11 to conceptualize differences; the arrows are 3x actual displacements.
« Last Edit: March 12, 2018, 10:30:52 PM by A-Team »

vigilius

  • ASIF Citizen
  • Posts: 125
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1360 on: March 13, 2018, 03:23:34 PM »
So which brave soul will open the melting season thread?

https://climatecrocks.com/2018/03/12/graph-of-the-day-summer-melt-begins-in-arctic/

From Eric Holhaus

colchonero

  • ASIF Lurker
  • Posts: 20
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1361 on: March 13, 2018, 03:37:51 PM »
@vigilius

That map is incorrect, I mean not exactly incorrect but it was too early to call the end of freezing season. After that tweet (or maybe even before, I don't know when he wrote it, but certainly after the date on the map) JAXA sea ice extent jumped a lot, and we have new maximum right now, with maybe even more to go. NSIDC also has updated and shows new season high.

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 5187
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 51
  • Likes Given: 56
Re: The 2017/2018 freezing season
« Reply #1362 on: March 13, 2018, 03:59:23 PM »
Here's Hautbois' most recent version of that graph:

Il faut cultiver notre jardin

Gray-Wolf

  • ASIF Middle Class
  • Posts: 692
    • View Profile
  • Liked: 6
  • Likes Given: 32
Re: The 2017/2018 freezing season
« Reply #1363 on: March 13, 2018, 04:19:44 PM »
I think we generally leave it 3 weeks before calling it due to the ups and downs at seasons end?

Then if we suddenly shed a million it might be safe to call it!!! :)
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

Shared Humanity

  • ASIF Governor
  • Posts: 2804
    • View Profile
  • Liked: 39
  • Likes Given: 3
Re: The 2017/2018 freezing season
« Reply #1364 on: March 13, 2018, 07:13:19 PM »
If you look at the plot of the daily range, both the upper and lower bounds are in decline by day 75. While this doesn't mean an individual year can't continue to climb, this might be something to watch. Also, only 6 or 21% of the yearly max's occurred after day 75.

FishOutofWater

  • ASIF Citizen
  • Posts: 437
    • View Profile
  • Liked: 40
  • Likes Given: 17
Re: The 2017/2018 freezing season
« Reply #1365 on: March 13, 2018, 07:31:33 PM »
Cold air flowing over the sea of Okhotsk will keep the sea ice increasing there for the next week or so. The sea of Okhotsk is where most of the recent ice extent increase has taken place. I don't know if that explains the discrepancy with Eric Holthaus' Tweet & map by Zack Labe showing that the max extent has already been reached.

I think we will see the max in about 7 days if the sea of Okhotsk is included in the extent figures.


Blizzard92

  • ASIF Lurker
  • Posts: 60
    • View Profile
    • Personal Research Website
  • Liked: 0
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1366 on: March 13, 2018, 07:59:17 PM »
I didn't claim the max sea ice extent was reached. The graphic was outdated.

Latest...
UC Irvine - Earth System Science Ph.D. Candidate
Cornell University - Atmospheric Sciences B.Sc.

Twitter: @ZLabe
Website: http://sites.uci.edu/zlabe/

Neven

  • Administrator
  • ASIF Royalty
  • *****
  • Posts: 5187
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 51
  • Likes Given: 56
Re: The 2017/2018 freezing season
« Reply #1367 on: March 13, 2018, 08:47:21 PM »
The graphic was outdated.

That's what I assumed as well. JAXA didn't update for a day or two (three?), but if someone didn't know that, he/she would assume the graph was up-to-date.

The only interesting question is whether we'll see another record low maximum (third in a row for JAXA, I believe).
Il faut cultiver notre jardin

Niall Dollard

  • ASIF Citizen
  • Posts: 190
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2017/2018 freezing season
« Reply #1368 on: March 13, 2018, 09:51:19 PM »
NSIDC also has updated and shows new season high.

And for the first time since Feb 6th, the charctic 2018 line is no longer bottom of the pile.

For Mar 12th, the 2015 figure of 14.308 million km2 is just below the 2018 figure (14.316 million km2)

Cold air flowing over the sea of Okhotsk will keep the sea ice increasing there for the next week or so. The sea of Okhotsk is where most of the recent ice extent increase has taken place.


Hasn't there been recent increases in the Barents also ?

Dharma Rupa

  • ASIF Citizen
  • Posts: 245
    • View Profile
  • Liked: 11
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1369 on: March 13, 2018, 10:38:58 PM »
Now that the freezing season is nearly over it might be a good time to look at the 180-day temperature anomaly:

oren

  • ASIF Upper Class
  • Posts: 2162
    • View Profile
  • Liked: 82
  • Likes Given: 176
Re: The 2017/2018 freezing season
« Reply #1370 on: March 14, 2018, 01:11:05 AM »
Cold air flowing over the sea of Okhotsk will keep the sea ice increasing there for the next week or so. The sea of Okhotsk is where most of the recent ice extent increase has taken place.
Hasn't there been recent increases in the Barents also ?
Actually the AMSR2 regional graphs show an increase in the Barents but also in the Bering, which seems to threaten its previous Feb 6th max.

cesium62

  • ASIF Citizen
  • Posts: 268
    • View Profile
  • Liked: 3
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1371 on: March 14, 2018, 06:09:41 AM »
If you look at the plot of the daily range, both the upper and lower bounds are in decline by day 75. While this doesn't mean an individual year can't continue to climb, this might be something to watch. Also, only 6 or 21% of the yearly max's occurred after day 75.

Also, on the NSIDC graph (charctic) 2017, 2016, and 2015 had converged around day 74 to 75 and split in interesting directions after that.  2018 is currently heading toward that convergence.  If extent doesn't drop dramatically in the next 4 or 5 days, I'd also like to see what happens on day 76 before calling the start of melting season.  2015 and 2016 each gained about 150K km^2 from day 71 to day 85 or 86.

Daniel B.

  • ASIF Middle Class
  • Posts: 636
    • View Profile
  • Liked: 8
  • Likes Given: 28
Re: The 2017/2018 freezing season
« Reply #1372 on: March 14, 2018, 11:46:13 AM »
If you look at the plot of the daily range, both the upper and lower bounds are in decline by day 75. While this doesn't mean an individual year can't continue to climb, this might be something to watch. Also, only 6 or 21% of the yearly max's occurred after day 75.

Also, on the NSIDC graph (charctic) 2017, 2016, and 2015 had converged around day 74 to 75 and split in interesting directions after that.  2018 is currently heading toward that convergence.  If extent doesn't drop dramatically in the next 4 or 5 days, I'd also like to see what happens on day 76 before calling the start of melting season.  2015 and 2016 each gained about 150K km^2 from day 71 to day 85 or 86.

Based on recent ice growth, I would not be surprise if we passed all three years over the next week.  Current low Arctic temperatures (some of the coldest this winter) are likely to enhance this growth.  What happens afterwards?  As you state, we shall see.

uniquorn

  • ASIF Citizen
  • Posts: 207
    • View Profile
  • Liked: 35
  • Likes Given: 7
Re: The 2017/2018 freezing season
« Reply #1373 on: March 14, 2018, 11:57:30 AM »
Okhotsk and Bering sea ice concentration Mar1-13 (uni-hamburg)
no predictions ;)
edit:one frame was wrong in original image.
« Last Edit: March 14, 2018, 12:11:32 PM by uniquorn »

uniquorn

  • ASIF Citizen
  • Posts: 207
    • View Profile
  • Liked: 35
  • Likes Given: 7
Re: The 2017/2018 freezing season
« Reply #1374 on: March 14, 2018, 12:56:13 PM »
Kara and Barents sea ice concentration Mar1-13 (uni-hamburg)

romett1

  • ASIF Citizen
  • Posts: 220
    • View Profile
  • Liked: 4
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1375 on: March 14, 2018, 01:56:57 PM »
Meanwhile nice cyclone approaching Bering Sea over the weekend bringing warmer weather and probably stirring things up there.

oren

  • ASIF Upper Class
  • Posts: 2162
    • View Profile
  • Liked: 82
  • Likes Given: 176
Re: The 2017/2018 freezing season
« Reply #1376 on: March 15, 2018, 01:37:19 AM »
Uniquorn, thanks for these animations. I am deeply concerned with the continuing weakness near the Bering Strait, even though extent grew significantly in the past few days, as this could easily change.
Last year blips of less-than full extent in the Chukchi trouble began mid-April, while real trouble began around May 10th. I am anxiously awaiting to see if this year will bring more trouble earlier.

slow wing

  • ASIF Middle Class
  • Posts: 598
    • View Profile
  • Liked: 8
  • Likes Given: 50
Re: The 2017/2018 freezing season
« Reply #1377 on: March 15, 2018, 02:21:36 AM »
As a scenario for this year, suppose open water North of the Bering Strait & of Svalbard comprise an area of 10% of the Arctic basin by around the Summer solstice.

Can winds then fill up those regions with ice while - to conserve ice area - leaving leads throughout the Arctic basin?

Because open water absorbs sunlight much more efficiently than ice does, those leads could then seed wider gaps in the ice, reinforcing the effect.

Could the Arctic ice melt out that way rather than predominantly getting eaten away at the edges?

Could the ice go like that given sufficient open water to start with at the edges of the Arctic basin? Or is the wind movement too slow to spread the effect through the Arctic basin in a melt season. (Doubtful. I think it's fast enough.) Or, instead, does the ice mainly hold together and most of the open water areas remain at the periphery? Or, as a fourth model, does the ice spread out as it shifts around and any leads are more transitory?

Which of the four is the most appropriate mechanical model for the Arctic sea ice?

jdallen

  • ASIF Governor
  • Posts: 2646
    • View Profile
  • Liked: 22
  • Likes Given: 50
Re: The 2017/2018 freezing season
« Reply #1378 on: March 15, 2018, 06:03:04 AM »
As a scenario for this year, suppose open water North of the Bering Strait & of Svalbard comprise an area of 10% of the Arctic basin by around the Summer solstice.
<snip>
Because open water absorbs sunlight much more efficiently than ice does, those leads could then seed wider gaps in the ice, reinforcing the effect.
<snip>
I think this is exactly the reason why the lack of melt ponds in recent years hasn't helped with preservation of the ice.  That extra open water significantly reduces the over-all albedo of the Arctic at a time of rising insolation (equinox to solstice) which otherwise would not permit the capture of insolation.  I should crunch some numbers...
« Last Edit: March 15, 2018, 05:23:45 PM by jdallen »
This space for Rent.

A-Team

  • ASIF Upper Class
  • Posts: 2214
    • View Profile
  • Liked: 103
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1379 on: March 15, 2018, 03:10:51 PM »
Quote
Could the Arctic ice melt out that way rather than predominantly getting eaten away at the edges? Could the ice go like that given sufficient open water to start with at the edges of the Arctic basin? Or is the wind movement fast enough.
Interesting line of thought. While thermodynamics (Arctic amplification of global atmospheric warming) has brought about downward trend lines in volume and area, transitioning to a 'seasonally ice covered' state (as P Wadham puts it) brings in other players such as enhanced ice mobility, peripheral melt geometry and timing, island and basin constraints, and increased intra- and inter-basin export.

In my view, this largely explains enormous timing discrepancy between thermodynamics-focused modeling (2050) and observation-driven Arctic field work (2020). The former approach will prove dead wrong: we could have a late summer blowout at any time.

People here go on about early August 2012 cyclonic winds but CCW stress on the ice primarily disperses it while disfavoring export. The CW circulation in late summer 2007 did both and that year was the real near-miss. Here we are now, eleven years later with the multi-year ice about gone and with it the resilience of thicker ice.

The icepack today responds immediately in proportion to the wind stress distribution, revealing daily translations, rotations, deformations and opening/closing of leads, even at the low resolution of an Ascat image having only 350 pixels wide for a 2000 km Arctic Ocean span.

While it's fairly easy to compare inter-annual deformation, it's fairly hard to take out variability in wind stress and its uneven areal distribution and thus difficult to establish empirical trends in ice plasticity in the continuum mechanics perspective or that of floe caliper sizes, fractures, leads, over-rafting, and ridging in the solid mechanics formulation.

The wind stress has affected the ice very unevenly over the last ten months, leading to very few regions exhibiting coherent net motion. There's been a slight trend to clockwise rotation on periphery but days of motion reversal are a good part of the mix, not to mention the late February over-the-pole narrow swath of deformation that extended from Svalbard to the Chukchi.

It's quite feasible to look at the near-term GFS nullschool wind forecast and accurately anticipate the response of the ice. It's debatable though whether longer term pattern trackers (NAO, AO, PDO, ENSO, MJO, SSW etc) offer any value to anticipating future ice movement.

This coming week, the strong lift-off along the western CAA will continue, with the NW Passage cork west of Banks Island perhaps popping out of the bottle and becoming entrained in the Beaufort stringer of thick floes. The other odd feature is persistent winds carrying ice into the Kara and then west through the Barents. While this disperses the ice and in doing so distorts extent statistics, the main event comes later with melt-out in the already over-heated waters around Svalbard.

As we transition to a melt season forum, it may be helpful to have some time series on hand that cover pre-conditioning from the freeze season. I'll add to these gradually here but update them for melt season as that forum emerges, for 2018 only to keep file sizes lower.

I expect very early development of an open water periphery from melt-out of the Chukchi where the ice never properly formed and the insolation kicks in early. CW circulation will then bring ice from the Beaufort and western CAA into a certain melt zone.

There will also be early and extensive melt along the Svalbard-FJL-SZ line where insolation comes late but already-intruded warm Atlantic Water is the controlling feature. The Kara ice has been disintegrating for weeks and that shed into the Barents will also disappear by mid-spring.

Overall, the central light and dark blues towards the end of the mp4 false-color suggest an outline for the ice that will remain before further wind dispersion is considered. The reds and greens will melt out or be exported.
« Last Edit: March 15, 2018, 04:33:47 PM by A-Team »

Gray-Wolf

  • ASIF Middle Class
  • Posts: 692
    • View Profile
  • Liked: 6
  • Likes Given: 32
Re: The 2017/2018 freezing season
« Reply #1380 on: March 15, 2018, 03:27:24 PM »
We all lived through the years of the 'babies arm' (across Beaufort and up into ESS) and how the 'hostile waters' were able to take out that 'good ice' in late season?
This move toward 'low numbers' in both ocean entrances leads to the 'hostile waters' slow wing is talking about and all we need is for windfields to drive ice at such ice killing ocean regions to see the ice go even with a 'cool, cloudy' central basin?

Today we are seeing ice breakup and float apart plump up the 'growth' in both Bering and Barentsz
so we must be seeing late formed FY ice replacing cover where they came from?

I spent so many years concerned about the 'perfect melt storm' synoptic that I missed this evolution of the basin?

In the past Fram would take ice to its doom but , over the years with ever more open water come equinox, those hostile waters are encroaching on the peripheral areas themselves and this may prove enough, under the correct wind/wave conditions, to do great damage to the ice.
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

FishOutofWater

  • ASIF Citizen
  • Posts: 437
    • View Profile
  • Liked: 40
  • Likes Given: 17
Re: The 2017/2018 freezing season
« Reply #1381 on: March 15, 2018, 04:48:35 PM »
With the corks pulled we will see more sea ice and fresh water loss through the CAA this summer and fall. The ice killing zone on the Pacific side of the Arctic ocean is also expanding. Even if we don't have perfect conditions this summer conditions are in place for the continued decline of sea ice volume and the destruction of the thickest sea ice.

A-Team

  • ASIF Upper Class
  • Posts: 2214
    • View Profile
  • Liked: 103
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1382 on: March 15, 2018, 05:18:48 PM »
Here is a synchronized version of the 15 Sept 17 to 14 Mar 18 movies above, plus a standalone of sea ice drift velocities which is convenient for identifying windstorm events.

uniquorn

  • ASIF Citizen
  • Posts: 207
    • View Profile
  • Liked: 35
  • Likes Given: 7
Re: The 2017/2018 freezing season
« Reply #1383 on: March 15, 2018, 06:29:42 PM »
Quote
The Kara ice is already disintegrated

Ice movement(export?) in the Kara Sea, Mar6-15.

Worldview brightness temperature band15 night, Terra/Modis day for reference

edit: I can't upload images at the moment
« Last Edit: March 15, 2018, 06:38:29 PM by uniquorn »

Niall Dollard

  • ASIF Citizen
  • Posts: 190
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2017/2018 freezing season
« Reply #1384 on: March 15, 2018, 08:20:02 PM »
Quote
The Kara ice is already disintegrated

Ice movement(export?) in the Kara Sea, Mar6-15.


The Kara Sea itself doesn't look much different to other years. It's at max extent and remains to be seen how thick it is and how quick it will melt.

With recent drift and wind it is expanding SW over the top of Novaya Zemlya into the northern Barents. Over there it looks fractured/disjointed but that would be nothing new for the northern Barents.

A-Team

  • ASIF Upper Class
  • Posts: 2214
    • View Profile
  • Liked: 103
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1385 on: March 15, 2018, 11:46:09 PM »
Quote
Kara Sea itself doesn't look much different to other years. It's at max extent and remains to be seen
You're joking, right?
« Last Edit: March 15, 2018, 11:52:19 PM by A-Team »

Daniel B.

  • ASIF Middle Class
  • Posts: 636
    • View Profile
  • Liked: 8
  • Likes Given: 28
Re: The 2017/2018 freezing season
« Reply #1386 on: March 16, 2018, 01:45:05 AM »
I think he is serious, as the sea is completely frozen.  I would call that a maximum.

Niall Dollard

  • ASIF Citizen
  • Posts: 190
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2017/2018 freezing season
« Reply #1387 on: March 16, 2018, 02:23:04 AM »
Disintegration ? Expansion ?

I have seen quite a few maps of the Kara Sea, like the one I have attached which indicates anything left of Novaya Zemlya is Barents (which makes more geographic sense to me).

But leaving that aside. From the standard definition of sea ice extent, the spreading out of the ice has resulted in expansion of the sea ice extent over Barents in recent weeks. Kara is also virtually at max.

As time goes on it's likely to become more compact. But all in all I don't see anything unusual about the condition of the ice in the northern Barents. Compared against this time 2016, there is a lot more ice about.

Killian

  • ASIF Lurker
  • Posts: 19
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1388 on: March 16, 2018, 02:29:46 AM »
If you look at the plot of the daily range, both the upper and lower bounds are in decline by day 75. While this doesn't mean an individual year can't continue to climb, this might be something to watch. Also, only 6 or 21% of the yearly max's occurred after day 75.

Also, on the NSIDC graph (charctic) 2017, 2016, and 2015 had converged around day 74 to 75 and split in interesting directions after that.  2018 is currently heading toward that convergence.  If extent doesn't drop dramatically in the next 4 or 5 days, I'd also like to see what happens on day 76 before calling the start of melting season.  2015 and 2016 each gained about 150K km^2 from day 71 to day 85 or 86.

Based on recent ice growth, I would not be surprise if we passed all three years over the next week.  Current low Arctic temperatures (some of the coldest this winter) are likely to enhance this growth.  What happens afterwards?  As you state, we shall see.

Yes, as the AO is also heading positive over the next week. There is only about 87,000 k/sq between the low and where it is now, so almost certain this will be exceeded.

Michael Hauber

  • ASIF Middle Class
  • Posts: 692
    • View Profile
  • Liked: 2
  • Likes Given: 1
Re: The 2017/2018 freezing season
« Reply #1389 on: March 16, 2018, 02:58:52 AM »
Looks like strong northerly winds are pushing thick solid ice into the Kara/Barents border region (and causing the pretty cloud streets just past the ice edge).  The cracks might look impressive, but the bigger the cracks, the thicker the ice.

However the issue is that these winds have pulled ice away from Kara/Laptev border region which has an area of open water, and finer cracking patterned ice which is probably thinner.
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Lord M Vader

  • ASIF Upper Class
  • Posts: 1183
    • View Profile
  • Liked: 6
  • Likes Given: 3
Re: The 2017/2018 freezing season
« Reply #1390 on: March 16, 2018, 08:55:18 AM »
The 2018 freezing seson should likely end in 48 hours as warm southerlies will start to dominate again in Berings Sea which should do big damage to the thin ice there and start the onset of the 2018 melting season.

Ninebelowzero

  • ASIF Lurker
  • Posts: 85
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: The 2017/2018 freezing season
« Reply #1391 on: March 16, 2018, 12:28:19 PM »
Interesting to see that particular cloud formation in the bottom right of this picture.



Anyone studying cloud formations in the arctic?

This is  reminiscent of some features usually seen well in to the melting season and further South. Close up it looks like a carpet pile and am I right in thinking it's streaming away from the area of high ice disintegration

A-Team

  • ASIF Upper Class
  • Posts: 2214
    • View Profile
  • Liked: 103
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1392 on: March 16, 2018, 04:15:44 PM »
Quote
Kara business as usual
Quote
the bigger the cracks, the thicker the ice
Why do you two post wild personal speculation about Kara sea ice thickness when carefully calibrated daily online satellite data is just a click away? This forum is not a chat room, we try to link to supporting data rather than just opine and share primitive idées fixes.

Perhaps loop the Kara sea ice export mp4s below over and over until you get it, next consider the OSI ice movement, sea ice temperature and AMSR2 concentration displays posted just up-forum, maybe read the twenty previous explanations of what is going here, what is coming next and why it matters for melt season.
« Last Edit: March 16, 2018, 05:08:02 PM by A-Team »

Sterks

  • ASIF Citizen
  • Posts: 174
  • Member # 1000
    • View Profile
  • Liked: 1
  • Likes Given: 4
Re: The 2017/2018 freezing season
« Reply #1393 on: March 16, 2018, 05:02:50 PM »
Quote
Why [...] just opine.

Michael is generally good with detail and checks work thoroughly, but there have been one or two minor errors here and there

Sterks

  • ASIF Citizen
  • Posts: 174
  • Member # 1000
    • View Profile
  • Liked: 1
  • Likes Given: 4
Re: The 2017/2018 freezing season
« Reply #1394 on: March 16, 2018, 05:11:08 PM »
the onset of the 2018 melting season.
Hear hear

Shared Humanity

  • ASIF Governor
  • Posts: 2804
    • View Profile
  • Liked: 39
  • Likes Given: 3
Re: The 2017/2018 freezing season
« Reply #1395 on: March 16, 2018, 05:19:19 PM »
Quote
Why [...] just opine.

Michael is generally good with detail and checks work thoroughly, but there have been one or two minor errors here and there

Why not just look at the multiple images which A-Team has posted and clearly show ice thickness across the Kara and Barents? Much of that "thick solid ice" being pushed into the Barents Kara border region is less than a half meter thick and the Kara in general has ice that is less than 1.5 meters thick except for the ice nearest the coast.

Daniel B.

  • ASIF Middle Class
  • Posts: 636
    • View Profile
  • Liked: 8
  • Likes Given: 28
Re: The 2017/2018 freezing season
« Reply #1396 on: March 16, 2018, 05:39:24 PM »
The 2018 freezing seson should likely end in 48 hours as warm southerlies will start to dominate again in Berings Sea which should do big damage to the thin ice there and start the onset of the 2018 melting season.

I am not so sure about that.  The freeing season could last another week, but not much longer.

jdallen

  • ASIF Governor
  • Posts: 2646
    • View Profile
  • Liked: 22
  • Likes Given: 50
Re: The 2017/2018 freezing season
« Reply #1397 on: March 16, 2018, 06:11:34 PM »
The 2018 freezing seson should likely end in 48 hours as warm southerlies will start to dominate again in Berings Sea which should do big damage to the thin ice there and start the onset of the 2018 melting season.

I am not so sure about that.  The freeing season could last another week, but not much longer.
Concur. Max has just happened or will in the next few days, and I doubt it will get much if any higher.

Peripheral melt will rapidly overtake any expansion at higher latitudes. I expect the Bering and Chukchi to start crashing hard by the first week of April.
This space for Rent.

FishOutofWater

  • ASIF Citizen
  • Posts: 437
    • View Profile
  • Liked: 40
  • Likes Given: 17
Re: The 2017/2018 freezing season
« Reply #1398 on: March 16, 2018, 06:16:51 PM »
Cold winds are forecast to continue to blow offshore in the Kara sea and the sea of Okhotsk for the next week or so. The reduction in sea ice extent caused by southerly winds in the Bering sea will likely be more than offset by continuing formation of thin ice where the cold offshore winds will blow.

This late increase in sea ice extent reminds me of 2012. Thicker ice is being blown into southerly locations where it will quickly melt out and very thin ice is replacing it near the continental margins. This is a set up for a collapse in volume, area and extent in May and June if the weather is warm.

Large areas of Eurasia's temperate zone have been much warmer than normal over the past ten days and the warm temperate and south Asia pattern seems to be set in stone in the weather models for the next 2 weeks. Snow is retreating faster than normal in the temperate zone while its cold on the shores of the Arctic. Again, this is a set up for a rapid Arctic warm up in May and June.

gerontocrat

  • ASIF Upper Class
  • Posts: 2180
    • View Profile
  • Liked: 95
  • Likes Given: 8
Re: The 2017/2018 freezing season
« Reply #1399 on: March 16, 2018, 08:32:26 PM »

There is an awful lot of water locked up in snow cover right now, more than usual, and I'm thinking in particular of N. America. 

I've been thinking about snow, especially a comment from A-Team some time ago about the Arctic being a desert - i.e. dry. I looked at Greenland, and certainly as you head North it goes from pretty dry to very dry. Then I looked at N.America and data from Environment Canada.

I assumed that nearly all Canada is under some snow by this time, and about 2 million km2 of the USA's nearly 10 million km2 area also is under snow. I then shoved data into a simple table see below).

And what do I see - this 2017-18 amazing winter snowfall in N.America is about 1 1/2 inches in snow water equivalent above the average, and still one half the average in Greenland.

So, unless my arithmetic is totally down the swanee (a decimal point or two astray), I am left with one question - Like , what's the big deal about some snow?
"Para a Causa do Povo a Luta Continua!"