Support the Arctic Sea Ice Forum and Blog

Author Topic: The 2020 melting season  (Read 1147478 times)

GAWLab

  • New ice
  • Posts: 24
    • View Profile
  • Liked: 86
  • Likes Given: 22
Re: The 2020 melting season
« Reply #2150 on: July 04, 2020, 12:14:44 AM »
Thanks for sharing!

So this camera is facing west, Kevin?

Sorry to take so long to get back to you, this thread moves quite quickly!

No, the camera is facing almost directly south, in fact.
- Kevin
Operator, Dr. Neil Trivett Global Atmosphere Watch Observatory
Alert, NU

interstitial

  • Young ice
  • Posts: 2893
    • View Profile
  • Liked: 573
  • Likes Given: 96
Re: The 2020 melting season
« Reply #2151 on: July 04, 2020, 12:23:01 AM »
Hycom forcast most of less then 1 meter ice melting in the Greenland Sea and Baffin bay melting to less than 0.1 meter this week with little change in area. I expect a major drop in area in the peripheral seas the following week.
This is a good prediction to test accuracy with.



Substantial volume melt of Chukchi and Beaufort seas volume but again not much visable area loss.

GoSouthYoungins

  • Nilas ice
  • Posts: 1427
    • View Profile
  • Liked: 150
  • Likes Given: 109
Re: The 2020 melting season
« Reply #2152 on: July 04, 2020, 12:25:15 AM »
Beaufort Sea ice should be fine at the end of the season. Everywhere else...  :-\
big time oops

peterlvmeng

  • Frazil ice
  • Posts: 143
    • View Profile
  • Liked: 35
  • Likes Given: 9
Re: The 2020 melting season
« Reply #2153 on: July 04, 2020, 02:18:20 AM »
Interesting.

Thanks for your post. Could you share the link of this website?

interstitial

  • Young ice
  • Posts: 2893
    • View Profile
  • Liked: 573
  • Likes Given: 96
Re: The 2020 melting season
« Reply #2154 on: July 04, 2020, 03:31:31 AM »
Interesting.

Thanks for your post. Could you share the link of this website?
A note of caution many of the more experienced members don't put much value in this model. There is some disagreement on the mater

HYCOM
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arc_list_arcticictn.html
probably should start here
https://www.hycom.org/dataserver/gofs-3pt1/reanalysis
« Last Edit: July 04, 2020, 03:40:35 AM by interstitial »

Pagophilus

  • Grease ice
  • Posts: 705
    • View Profile
  • Liked: 434
  • Likes Given: 581
Re: The 2020 melting season
« Reply #2155 on: July 04, 2020, 03:58:45 AM »
Hycom forcast most of less then 1 meter ice melting in the Greenland Sea and Baffin bay melting to less than 0.1 meter this week with little change in area. I expect a major drop in area in the peripheral seas the following week.
This is a good prediction to test accuracy with.

In this context, Gerontocrat wrote the following a few hours ago on the area and extent thread:

NSIDC Sea Ice Area - random observations.

The contrast between the sea ice area in the High Arctic (2nd lowest) and the Peripheral Seas (13th lowest) is, if anything, increasing. It may all end up largely depending on the balance between ice export from the Central Arctic into the Greenland Sea.

The Laptev Sea melt continues apace.

The Central Arctic Sea is suddenly losing a lot of sea ice area - i.e. melt is nibbling away at North of 80.

And the AMSR2 image from July 2 sure makes the Peripheral Seas ice look in a delicate state...
« Last Edit: July 04, 2020, 04:23:52 AM by Pagophilus »
You may delay, but time will not.   Benjamin Franklin.

interstitial

  • Young ice
  • Posts: 2893
    • View Profile
  • Liked: 573
  • Likes Given: 96
Re: The 2020 melting season
« Reply #2156 on: July 04, 2020, 04:07:16 AM »
Despite strong Melt in the CAA there apears to be at least a section of 2 m ice still blocking each route through.

Pavel

  • Frazil ice
  • Posts: 264
    • View Profile
  • Liked: 48
  • Likes Given: 9
Re: The 2020 melting season
« Reply #2157 on: July 04, 2020, 06:43:52 AM »
Beaufort Sea ice should be fine at the end of the season. Everywhere else...  :-\
However the bottom melt in the Beaufort sea will continue well into September and even October. It's not the safe place to store the extra volume.

wallen

  • Frazil ice
  • Posts: 115
    • View Profile
  • Liked: 52
  • Likes Given: 2
Re: The 2020 melting season
« Reply #2158 on: July 04, 2020, 07:24:23 AM »
Beaufort Sea ice should be fine at the end of the season. Everywhere else...  :-\
However the bottom melt in the Beaufort sea will continue well into September and even October. It's not the safe place to store the extra volume.

Added to that the decimation of the other seas that are adjacent to the Beaufort Sea, what impact that may have.

meddoc

  • Frazil ice
  • Posts: 264
    • View Profile
  • Liked: 11
  • Likes Given: 0
Re: The 2020 melting season
« Reply #2159 on: July 04, 2020, 08:47:43 AM »
Interesting.

Hycom switched in their Models from ArcC a couple of Years ago (I think 2017) to Glb-
which I don't know what exactly means- apart from taking off a large Section of 2m + Ice in their Maps.
So, it's not to be taken as an absolute Marker- rather just to follow Trends in melt.

Frivolousz21

  • Nilas ice
  • Posts: 1915
  • Live in Belleville, IL..15 miles SE of St. Louis.
    • View Profile
  • Liked: 598
  • Likes Given: 7
Re: The 2020 melting season
« Reply #2160 on: July 04, 2020, 08:59:43 AM »
Hycom has so little value. 

The best way to give it any level of validity is to compare what it shows at the very start of April versus cryosat 2 early April thickness.

Even then the evolution of what hycom shows could be total garbage.

But cryosat and ice sat 2 are the best sea ice thickness measures we have.

I got a nickname for all my guns
a Desert Eagle that I call Big Pun
a two shot that I call Tupac
and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow

blumenkraft

  • Guest
Re: The 2020 melting season
« Reply #2161 on: July 04, 2020, 09:07:16 AM »
... south ...

Oh OK. :)

Thanks a lot.

blumenkraft

  • Guest
Re: The 2020 melting season
« Reply #2162 on: July 04, 2020, 09:15:04 AM »
Beaufort Sea ice should be fine at the end of the season. Everywhere else...  :-\
However the bottom melt in the Beaufort sea will continue well into September and even October. It's not the safe place to store the extra volume.

Indeed! Check Uniquorn's post here >> https://forum.arctic-sea-ice.net/index.php/topic,2417.msg271684.html#msg271684

The water is getting warmer there.

ArcticMelt2

  • Grease ice
  • Posts: 929
    • View Profile
  • Liked: 187
  • Likes Given: 37
Re: The 2020 melting season
« Reply #2163 on: July 04, 2020, 09:15:33 AM »
Area with low ice concentration continues to grow in size

oren

  • Moderator
  • First-year ice
  • Posts: 9815
    • View Profile
  • Liked: 3587
  • Likes Given: 3935
Re: The 2020 melting season
« Reply #2164 on: July 04, 2020, 09:32:38 AM »
The Beaufort stands out. This melting season which is quite aggressive everywhere else has left the region with very high area, second only to 2013 in the AMSR2 record. PIOMAS also indicates high volume. Normally the Beaufort loses a lot of ice due to transport towards the Chukchi, compensated by some thicker ice arriving from the CAB and the CAA. This year the westward transport has been very muted, while the in-situ melting in the Beaufort is not enough to generate open water this early in the season. Thus the positive feedback loop of open water soaking up the sun's energy and leading to more open water is much weaker this year. At the same time, the Chukchi has been running rather high as well, the western CAB shows no special signs of weakness, and the CAA ice is unbroken in the main channels. So while import from the CAB is expected to increase in the coming days due to the anti-cyclone, export doesn't have too many open outlets and will probably continue to be low.
This can change if the CAA breaks up very early and a "garlic press" export begins, or the Chukchi ice crashes making room for import from the Beaufort, or the in-situ melting reaches a critical threshold, maybe with the help of some storm.
But in general I am predicting a high Beaufort area at the end of the melting season, probably over 100k km2 and not close to zero as most years. The only year that managed to get from a similarly high point on this date to near-zero was 2015, all other low minimum years were also much lower on this date. 2019 and 2016 had 200k km2 less area on this date, a very large difference.

Note: numbers based on Wipneus, using the smaller "CT" Beaufort region.

uniquorn

  • First-year ice
  • Posts: 5130
    • View Profile
  • Liked: 2172
  • Likes Given: 388
Re: The 2020 melting season
« Reply #2165 on: July 04, 2020, 11:23:12 AM »
Data from simb386840 temperature chain in the Beaufort, jul2-4 (no legend)
AirBuoy temps above surface on the left, ocean to the right.

Added a photo (courtesy of Josh Jones) of the simb buoy. The temperature chain is fitted along the tube.
Today's data from cryosphere innovation website showing much lower air temp so the string must be showing buoy temperature, a rough representation of insolation.

Last image is a closer look at those air temps, jul2-4
« Last Edit: July 04, 2020, 01:55:53 PM by uniquorn »

uniquorn

  • First-year ice
  • Posts: 5130
    • View Profile
  • Liked: 2172
  • Likes Given: 388
Re: The 2020 melting season
« Reply #2166 on: July 04, 2020, 11:57:29 AM »
The Siberian side using uni-hamburg amsr2-uhh, jun1-jul3. click to run

Also a look at the hudson-baffin area using uni-hamburg amsr2-uhh, jun1-jul3. click to run
« Last Edit: July 04, 2020, 01:52:19 PM by uniquorn »

ArcticMelt2

  • Grease ice
  • Posts: 929
    • View Profile
  • Liked: 187
  • Likes Given: 37
Re: The 2020 melting season
« Reply #2167 on: July 04, 2020, 01:44:48 PM »
Last June is the third among the warmest in the Arctic. But in general, the cold season is hardly among the top ten. So it is not surprising that PIOMAS continues to show only 4th place, and the Beaufort Sea is close to the norm.

gandul

  • Guest
Re: The 2020 melting season
« Reply #2168 on: July 04, 2020, 02:21:34 PM »
Both EC and GFS agree the anticyclone will persist centered and above 1030hPa for at least seven days more.

uniquorn

  • First-year ice
  • Posts: 5130
    • View Profile
  • Liked: 2172
  • Likes Given: 388
Re: The 2020 melting season
« Reply #2169 on: July 04, 2020, 02:59:09 PM »
A bit more buoy data from 386840 in the Beaufort. Here looking at temperatures (dtc values) between -4C and +4C to focus on the ice/ocean interface. There are some big changes towards the end of the animation. click to run
air temps and location in the subtitle

El Cid

  • Young ice
  • Posts: 2513
    • View Profile
  • Liked: 923
  • Likes Given: 227
Re: The 2020 melting season
« Reply #2170 on: July 04, 2020, 03:11:46 PM »
Interesting article about Polarstern's experiences this year:

https://www.economist.com/science-and-technology/2020/06/20/an-icebreaker-called-polarstern-is-revealing-the-arctics-secrets

Two things stood out: Strove said that ice is in reality mostly thinner than measurements and the other one is that as the ice opens up more organic matter comes from the sea that become "seeds" for precipitation (there is not much seeding material otherwise in the Arctic they say) which means that the Arctic will likely be more and more cloudy and rainy in summer which is a positive and during autumn which is a negative

gandul

  • Guest
Re: The 2020 melting season
« Reply #2171 on: July 04, 2020, 03:17:07 PM »
A bit more buoy data from 386840 in the Beaufort. Here looking at temperatures (dtc values) between -4C and +4C to focus on the ice/ocean interface. There are some big changes towards the end of the animation. click to run
air temps and location in the subtitle
Fast bottom warming as well due to draining water, crack,...?

peterlvmeng

  • Frazil ice
  • Posts: 143
    • View Profile
  • Liked: 35
  • Likes Given: 9
Re: The 2020 melting season
« Reply #2172 on: July 04, 2020, 03:26:21 PM »
Amazing!!!

ArcticMelt2

  • Grease ice
  • Posts: 929
    • View Profile
  • Liked: 187
  • Likes Given: 37
Re: The 2020 melting season
« Reply #2173 on: July 04, 2020, 03:45:44 PM »
The Laptev Sea yesterday reduced the Extent ice by almost 100 thousand km2 according to data NSDIC.

ArcticMelt2

  • Grease ice
  • Posts: 929
    • View Profile
  • Liked: 187
  • Likes Given: 37
Re: The 2020 melting season
« Reply #2174 on: July 04, 2020, 03:56:53 PM »
The difference with 2014 increased to 130 thousand km2 (data NSDIC Extent).

Sublime_Rime

  • Frazil ice
  • Posts: 218
    • View Profile
  • Liked: 98
  • Likes Given: 27
Re: The 2020 melting season
« Reply #2175 on: July 04, 2020, 03:59:20 PM »
Normally the Beaufort loses a lot of ice due to transport towards the Chukchi, compensated by some thicker ice arriving from the CAB and the CAA.

I very much agree Oren, that the Beaufort stands out as having been relatively well preserved relative to recent years.

The only point I'd qualify, is that there seems to be some substantial movement in the Chukchi into ESS, in addition to in situ melting, which I wonder might be the beginning of the "crash" in area/extent you speak of. That really stood out to me in Uniquorn's video  and area seems to have plummeted there in the past 2-3 days. If this continued over the next 5-7 days with the anticyclone, I could imagine it giving the Beaufort room for western export and expanding the open water in the Beaufort by July 10th or so.
Max
Know thyself
Here to learn and connect in these wondrous and quickly changing times.

ArcticMelt2

  • Grease ice
  • Posts: 929
    • View Profile
  • Liked: 187
  • Likes Given: 37
Re: The 2020 melting season
« Reply #2176 on: July 04, 2020, 04:13:43 PM »
http://nsidc.org/arcticseaicenews/2020/07/laptev-sea-lapping-up-the-heat-in-june/

Quote
The Siberian heat wave continued into June with a record high temperature in Verkhoyansk, just north of the Arctic Circle. The heat also affected the Laptev Sea, where ice extent dropped to a record low for this time of year. Sea ice extent was low overall in the Arctic Ocean, though not at record levels. Late June into early July is the period of most rapid ice loss in the Arctic.

http://nsidc.org/arcticseaicenews/files/1999/07/Figure4a.png

Quote
Figure 4a. This graph shows Laptev Sea ice extent for May 1 through July 31 for the 1979 to 2019 median (black) as well as the sea ice extent for May 1 through June 30, 2020 (red). Extent is shown in thousands of square kilometers. The graph also includes the 25 percent and 75 percent quartiles (gray), and the minimum and maximum sea ice extent (dashed black).


Quote
Sea ice extent in the Laptev Sea was at record low from June 19 through the end of the month. With the early opening of the Laptev Sea, ocean sea surface temperatures (SST) have already risen up to 4 degrees Celsius (7 degrees Fahrenheit) above freezing, according to NOAA SST data provided by the Upper layer Temperature o the Polar Oceans (UpTemp0) buoy site (Figure 4b). River runoff may also be contributing to the warm surface waters in the region.

Phoenix

  • Guest
Re: The 2020 melting season
« Reply #2177 on: July 04, 2020, 04:25:44 PM »
2020 has hit the jackpot. 5 day average loss in the CAB alone is 85k.  :o :o :o :o


romett1

  • Frazil ice
  • Posts: 286
    • View Profile
  • Liked: 32
  • Likes Given: 2
Re: The 2020 melting season
« Reply #2178 on: July 04, 2020, 05:21:42 PM »
Today's Worldview - I don't know the outcome if this area should get some kind of strong cyclone.

ArcticMelt2

  • Grease ice
  • Posts: 929
    • View Profile
  • Liked: 187
  • Likes Given: 37
Re: The 2020 melting season
« Reply #2179 on: July 04, 2020, 05:22:34 PM »
If you believe the picture from the Neven site, now 2020 is ahead of 2014 by a week in the Laptev Sea.



And the anomaly in the water temperature in the Laptev Sea in 2014 was much less.

Freegrass

  • Young ice
  • Posts: 3851
  • Autodidacticism is a complicated word
    • View Profile
  • Liked: 953
  • Likes Given: 1257
Re: The 2020 melting season
« Reply #2180 on: July 04, 2020, 05:23:09 PM »
A bit more buoy data from 386840 in the Beaufort. Here looking at temperatures (dtc values) between -4C and +4C to focus on the ice/ocean interface. There are some big changes towards the end of the animation. click to run
air temps and location in the subtitle
Fast bottom warming as well due to draining water, crack,...?
Crack is a different kind of ice...  ::)
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

WTF happened?

gandul

  • Guest
Re: The 2020 melting season
« Reply #2181 on: July 04, 2020, 05:35:39 PM »
A bit more buoy data from 386840 in the Beaufort. Here looking at temperatures (dtc values) between -4C and +4C to focus on the ice/ocean interface. There are some big changes towards the end of the animation. click to run
air temps and location in the subtitle
Fast bottom warming as well due to draining water, crack,...?
Crack is a different kind of ice...  ::)
Lol
I meant melt pond water drained around sun-heated instrumentation or drained down a crack in the ice nearby.

Freegrass

  • Young ice
  • Posts: 3851
  • Autodidacticism is a complicated word
    • View Profile
  • Liked: 953
  • Likes Given: 1257
Re: The 2020 melting season
« Reply #2182 on: July 04, 2020, 05:42:35 PM »
The Beaufort stands out. This melting season which is quite aggressive everywhere else has left the region with very high area, second only to 2013 in the AMSR2 record. PIOMAS also indicates high volume. Normally the Beaufort loses a lot of ice due to transport towards the Chukchi, compensated by some thicker ice arriving from the CAB and the CAA. This year the westward transport has been very muted, while the in-situ melting in the Beaufort is not enough to generate open water this early in the season. Thus the positive feedback loop of open water soaking up the sun's energy and leading to more open water is much weaker this year. At the same time, the Chukchi has been running rather high as well, the western CAB shows no special signs of weakness, and the CAA ice is unbroken in the main channels. So while import from the CAB is expected to increase in the coming days due to the anti-cyclone, export doesn't have too many open outlets and will probably continue to be low.
This can change if the CAA breaks up very early and a "garlic press" export begins, or the Chukchi ice crashes making room for import from the Beaufort, or the in-situ melting reaches a critical threshold, maybe with the help of some storm.
But in general I am predicting a high Beaufort area at the end of the melting season, probably over 100k km2 and not close to zero as most years. The only year that managed to get from a similarly high point on this date to near-zero was 2015, all other low minimum years were also much lower on this date. 2019 and 2016 had 200k km2 less area on this date, a very large difference.

Note: numbers based on Wipneus, using the smaller "CT" Beaufort region.
It took a long time before the Bering Sea melted out this year because there was a persistent northerly through the Bering Strait during the early melting season. This kept the Chukchi cold and caused the ice to move that way. I think that this is the main reason why the Atlantic side is so weak this year, while the Pacific side has more ice. And I think that this is probably the worse case scenario because the atlantic side is closer to the pole, and thus gets fewer insolation than the Pacific side. It is the opposite of what happened last season, when the pacific was weak, and the atlantic was strong.

But that's just the humble opinion from a fat guy on a computer. I'm not sure if there is any research on this?
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

WTF happened?

grixm

  • Grease ice
  • Posts: 699
    • View Profile
  • Liked: 374
  • Likes Given: 131
Re: The 2020 melting season
« Reply #2183 on: July 04, 2020, 05:48:33 PM »
Daily area is now lowest for the date.

gandul

  • Guest
Re: The 2020 melting season
« Reply #2184 on: July 04, 2020, 05:50:05 PM »
This anticyclone is powerful, +1035 hPa, meaning warmed air and insolation on top of the CAB, but it won't mean much heat transported from the continents from now on ten days or so. If is was off center, for instance forming a system with a Greenland high it would bring the warmth from NA, but there is no much clockwise circulation over Greenland, so this predicted centered circulation kind of protects the Arctic from continental warmth. These first days however there is circulation bringing warmth from the Pacific along the Eurasia coast toward the Atlantic. But then it will subside.
Will be interesting to see what weights more from this weather outcome.
« Last Edit: July 04, 2020, 05:59:02 PM by gandul »

F.Tnioli

  • Grease ice
  • Posts: 772
    • View Profile
  • Liked: 147
  • Likes Given: 38
Re: The 2020 melting season
« Reply #2185 on: July 04, 2020, 06:06:08 PM »
This anticyclone is powerful, +1035 hPa, meaning warmed air and insolation on top of the CAB, but it won't mean much heat transported from the continents from now on ten days or so. If is was off center, for instance forming a system with a Greenland high it would bring the warmth from NA, but there is no much clockwise circulation over Greenland, so this predicted centered circulation kind of protects the Arctic from continental warmth. These first days however there is circulation bringing warmth from the Pacific along the Eurasia coast toward the Atlantic. But then it will subside.
Will be interesting to see what weights more from this weather outcome.
Torching at peak insolation is the worst, as we've seen countless times. No question about it.
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

Aluminium

  • Nilas ice
  • Posts: 1463
    • View Profile
  • Liked: 1140
  • Likes Given: 680
Re: The 2020 melting season
« Reply #2186 on: July 04, 2020, 07:01:06 PM »
Warm air from continents is already in the Arctic. Given low albedo, sunshine will probably keep conditions of perfect melting storm even without new WAAs.

Freegrass

  • Young ice
  • Posts: 3851
  • Autodidacticism is a complicated word
    • View Profile
  • Liked: 953
  • Likes Given: 1257
Re: The 2020 melting season
« Reply #2187 on: July 04, 2020, 07:34:43 PM »
Latest Five Day Forecast
Wind + Temp @ Surface

In my world, the rule of thumb is that any movement of ice increases bottom melt as it increases the rate of transfer of energy and salinity between the ice and the water column. Or in layman words, stirring a glass containing water and ice hastens the melt-out.

Thanks Oren! So shall we call this the big stir?

Large GIF!
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

WTF happened?

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: The 2020 melting season
« Reply #2188 on: July 04, 2020, 07:41:33 PM »
2014 had a similar HP pattern, so comparisons are somewhat warranted. The big difference is that back then there where no heat import, just cold air circling around. 850 hPa temps were 5-10 C lower than they are now, and there was a lot of snow in the buoy-pictures which took forever to melt (the buoy thread seems dead now. I've been away for a while so I don't know why, but the 2014 pics will still be there for comparison). I think this is a pretty uniquely awful setup which does not come around very often. Unprecedented in the post-2007 era.

blumenkraft

  • Guest
Re: The 2020 melting season
« Reply #2189 on: July 04, 2020, 07:58:53 PM »
... I've been away for a while ...

Welcome back! :)

I like your username. ;)

gandul

  • Guest
Re: The 2020 melting season
« Reply #2190 on: July 04, 2020, 08:50:18 PM »
Latest Five Day Forecast
Wind + Temp @ Surface

In my world, the rule of thumb is that any movement of ice increases bottom melt as it increases the rate of transfer of energy and salinity between the ice and the water column. Or in layman words, stirring a glass containing water and ice hastens the melt-out.

Thanks Oren! So shall we call this the big stir?

Large GIF!
To be completely fair, the stirring should happen in the other direction to promote dispersion,. mechanical breakup of floes and bottom melt... One of the positive aspects of this setup is that it keeps ice compact...
Anyway, the 12z EC is slightly worse in strength and persistence of the 2020 GAH (Great Arctic High)

bbr2315

  • Grease ice
  • Posts: 580
    • View Profile
  • Liked: 73
  • Likes Given: 77
Re: The 2020 melting season
« Reply #2191 on: July 04, 2020, 09:03:06 PM »
Area with low ice concentration continues to grow in size
It looks like the soot from the wildfires was deposited over the growing area of low concentration approaching the Pole.

https://forum.arctic-sea-ice.net/index.php/topic,3142.msg271756.html#msg271756

This year does have some odd semblances to 2014 in terms of the Laptev situation but the temperatures, as others have posted, are just so much warmer on background both in the Arctic and over much of the continents.

2020 also does not have thick FYI or any MYI in the huge area below the CAB in Chukchi, etc. This "shield" is probably going to melt fully this year with some patches of MYI in Beaufort possibly remaining.

The ATL front..... I wonder what it is going to be like in 30 days. Will the Elves have drowned by then? Probably not... but by 8/15-9/1?

Ice Shieldz

  • Frazil ice
  • Posts: 249
    • View Profile
  • Liked: 59
  • Likes Given: 58
Re: The 2020 melting season
« Reply #2192 on: July 04, 2020, 09:44:39 PM »
Indeed the animations freegrass has been sharing are stunning - such a persistent high pressure melting pattern so perfectly covering all the arctic oceans. If it continues as forecasted, I think the label Great Arctic High is apropos, albeit with connotations  8)

Pagophilus

  • Grease ice
  • Posts: 705
    • View Profile
  • Liked: 434
  • Likes Given: 581
Re: The 2020 melting season
« Reply #2193 on: July 04, 2020, 09:47:20 PM »
To be completely fair, the stirring should happen in the other direction to promote dispersion,. mechanical breakup of floes and bottom melt... One of the positive aspects of this setup is that it keeps ice compact...
Anyway, the 12z EC is slightly worse in strength and persistence of the 2020 GAH (Great Arctic High)

In my inexperience, I am puzzled by what you write, gandul.  Would there not be dispersion as well as compaction with this clockwise rotation?  It looks like this 'stirring' should result in a lot of of Fram export, starting some possible Nares export, and ice also being spread out into all the open water in the now-warming Laptev Sea and into what is a rapidly melting Chukchi.  I understand that ice might tend to be jammed together along the Canadian side, but wouldn't it also be dispersed further in other areas, where it may well then rapidly melt?  I may be missing something and would be glad to learn.
« Last Edit: July 04, 2020, 10:09:01 PM by Pagophilus »
You may delay, but time will not.   Benjamin Franklin.

Steven

  • Grease ice
  • Posts: 957
    • View Profile
    • Arctic sea ice data and graphs
  • Liked: 481
  • Likes Given: 19
Re: The 2020 melting season
« Reply #2194 on: July 04, 2020, 10:15:31 PM »
It looks like this 'stirring' should result in a lot of of Fram export

I don't see much Fram export in that forecast.  Due to Coriolis force there's an angle of about 30 degrees between wind direction and sea ice drift, with the drift deviating toward the high pressure area, see the references here.  In the forecast posted above there won't be much ice crossing the boundary between CAB and Greenland Sea.

Pagophilus

  • Grease ice
  • Posts: 705
    • View Profile
  • Liked: 434
  • Likes Given: 581
Re: The 2020 melting season
« Reply #2195 on: July 04, 2020, 10:16:50 PM »
The news from the other area and extent thread via Gerontocrat and Juan is pretty momentous so I hope I may be allowed to bring it across here, with a deep bow to both gentlemen for their amazing, indefatigable work.  Alphabet summarizes the string of recent losses crisply.  Selectively quoted and I have also done some bolding.  Originals are all on the other thread.  I promise, o ye gods of the threads, not to do this again unless i really can't help myself...

JAXA ARCTIC SEA ICE EXTENT:  8,633,133 KM2 as at 03-Jul-2020

- Extent loss on this day 120k, 38 k more than the average loss on this day (of the last 10 years) of 82k,
- Extent loss from maximum on this date is 5,815 k, 449 k, 8.4% more than the 10 year average of 5,365 k.
- Extent is at position #1 in the satellite record
- Extent is  44 k LESS than 2019,
- Extent is  74 k LESS than 2016,
- Extent is  113 k LESS than 2012
- Extent is  431 k LESS than 2007

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 4.05 million km2, 0.87 million km2 above the 2012 minimum of 3.18 million km2.

Meanwhile...         
         
- 2020 area is at position #3 in the satellite record.
         
Very high area & extent losses look to be guaranteed for at least 2-3 days more.[/i]
NSIDC daily extent

This is getting ridiculous.

2020-06-27  9.854
2020-06-28  9.723  -131
2020-06-29  9.575  -148
2020-06-30  9.445  -130
2020-07-01  9.262  -183
2020-07-02  9.142  -120
2020-07-03  8.942  -200

« Last Edit: July 04, 2020, 10:22:18 PM by Pagophilus »
You may delay, but time will not.   Benjamin Franklin.

grixm

  • Grease ice
  • Posts: 699
    • View Profile
  • Liked: 374
  • Likes Given: 131
Re: The 2020 melting season
« Reply #2196 on: July 04, 2020, 10:21:54 PM »
To be completely fair, the stirring should happen in the other direction to promote dispersion,. mechanical breakup of floes and bottom melt... One of the positive aspects of this setup is that it keeps ice compact...
Anyway, the 12z EC is slightly worse in strength and persistence of the 2020 GAH (Great Arctic High)

In my inexperience, I am puzzled by what you write, gandul.  Would there not be dispersion as well as compaction with this clockwise rotation?  It looks like this 'stirring' should result in a lot of of Fram export, starting some possible Nares export, and ice also being spread out into all the open water in the now-warming Laptev Sea and into what is a rapidly melting Chukchi.  I understand that ice might tend to be jammed together along the Canadian side, but wouldn't it also be dispersed further in other areas, where it may well then rapidly melt?  I may be missing something and would be glad to learn.

Ice is generally pushed inwards under anticyclones (clockwise rotation). This is because the wind pushing on the ice actually makes the ice move at an angle further to the right than would be expected, because of the Coriolis effect. Here is a basic diagram on how the ice would move with this setup (probably a bit exaggerated). Of course this is approximate, and also doesn't account for ocean currents, collisions with other ice or land, etc.


Pagophilus

  • Grease ice
  • Posts: 705
    • View Profile
  • Liked: 434
  • Likes Given: 581
Re: The 2020 melting season
« Reply #2197 on: July 04, 2020, 10:32:40 PM »
To be completely fair, the stirring should happen in the other direction to promote dispersion,. mechanical breakup of floes and bottom melt... One of the positive aspects of this setup is that it keeps ice compact...
Anyway, the 12z EC is slightly worse in strength and persistence of the 2020 GAH (Great Arctic High)

In my inexperience, I am puzzled by what you write, gandul.  Would there not be dispersion as well as compaction with this clockwise rotation?  It looks like this 'stirring' should result in a lot of of Fram export, starting some possible Nares export, and ice also being spread out into all the open water in the now-warming Laptev Sea and into what is a rapidly melting Chukchi.  I understand that ice might tend to be jammed together along the Canadian side, but wouldn't it also be dispersed further in other areas, where it may well then rapidly melt?  I may be missing something and would be glad to learn.

Ice is generally pushed inwards under anticyclones (clockwise rotation). This is because the wind pushing on the ice actually makes the ice move at an angle further to the right than would be expected, because of the Coriolis effect. Here is a basic diagram on how the ice would move with this setup (probably a bit exaggerated). Of course this is approximate, and also doesn't account for ocean currents, collisions with other ice or land, etc.
Thank you, grixm, that is helpful to me.  I appreciate you taking the trouble.  I guess a whole lot depends on where that anticyclone locates itself.
 
In the model forecast gif, there are strong winds indicated that would drive ice through the Fram and Nares... just want to point that out.

One further question: this particular anticyclone, centering itself almost above the pole is going to produce motions that are essentially east-west, and so objects/masses being moved will be unusually 'immune' to the Coriolis Effect, which 'acts' most notably on objects/masses going north and south, will they not?  Or is it that Coriolis effects increase nearer the poles?  Or am I missing something else?
« Last Edit: July 04, 2020, 10:45:29 PM by Pagophilus »
You may delay, but time will not.   Benjamin Franklin.

Phoenix

  • Guest
Re: The 2020 melting season
« Reply #2198 on: July 04, 2020, 10:53:36 PM »
There are compacting and dispersing forces working simultaneously.

At the core of the anti-cyclone the ice is being compacted by Coriolis forces. On the perimeter, there are dispersing winds. On the NAM side, winds push Beaufort ice toward the NW Canada coast,  on the Siberian side, winds push ESS ice toward the open Laptev and on the Atlantic side, you have CAB ice being pushed toward Fram.

On the whole, my take from the event is net dispersion.

On a separate note....w/ PIOMAS numbers in....the 3 regions which are most likely to retain material volumes of ice at the minimum are clearly now CAB, Beaufort Sea and Greenland Sea. On a combined basis, these three seas have over 1,000 km3 more ice through this June vs. last year.

How much of that difference will 2020 make up over the rest of the summer ?


gandul

  • Guest
Re: The 2020 melting season
« Reply #2199 on: July 04, 2020, 11:00:26 PM »
Yes, grixm schematic is accurate as a big picture, but it's also true there's going to be a lot of transport toward Fram the first days.