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Messages - Phil42

Pages: [1]
1
Arctic sea ice / Re: The 2020/2021 freezing season
« on: Today at 07:41:31 AM »
October 21-25.

2019.

2
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 24, 2020, 05:38:58 AM »
October 19-23.

2019.

3
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 23, 2020, 05:43:08 PM »
Quote
weather is about to become propitious for a quick rebound of sea ice next week.
The time series below looks at the rate of change of SST over the last 16 weeks at 5 day intervals at a single central Laptev site, lat 77.77º. The open water surface temperature peaked at an astonishing 7.3ºC on Aug 17th.

There do not seem to have been any profiler buoys in the area so no data on how this temperature changed with depth to shelf. For shallow water and stratification lost to atlantification, the water may be fairly well mixed and the temperature profile flat.

It would have been better to take a 'reading' every day rather than every fifth, then repeating at say a dozen different locations by loading a list of manufactured urls as browser tabs, then turning the data over to Geronto for graphing with some kind of multi-regressional best fit. 

Another way to go is with a quantitative CMEMS grayscale for a 2D time series of the whole Siberian side. These can literally be subtracted to get at numerical temperature change between any two dates, put into a heat map palette, and averaged over any polygonal region. However CMEMS is very taken with politically correct (perceptually uniform) palettes; the grayscale may or may not be affected.

The series shown went from to 6.9ºC to 1.0ºC in 65 days, cooling roughly 0.1º per day. This could be quite misleading from a thermodynamic standpoint if vertical turbulence or horizontal currents shifted water masses about. Really severe and persistent cold air could also set in, contrary to forecast and past climatology.

However, if the nominal trend continues, the water at this lat/lon would reach -1.8º in the last week of November.

4
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 23, 2020, 08:41:20 AM »
What I am trying to bring up is that extent by itself is only an indication of when ice thickening can possibly begin, and with the current extreme delay in the Asian sea ice extent, the ice growth in thickness is being delayed. While historically some areas of the Asian seas have had slow growth in extent, 2020 is the first year on record (as far as I know) that will likely still have an ice free NE passage on Nov 1. (And not just dodging ice, but wide a open sea lane.) The fear is that if this continues much longer even with eventual universal 100% extent on the Asian side, that first year ice will not have a chance for a 'normal' gain in thickness. Instead of >1M ice, much of the Asian sea ice could end the freezing season in a very fragile state leading to much earlier breakup and melt in 2021. Already basically the whole of the Asian side has lost a month of thickness growth, where in previous years a fairly large percentage of those seas had already started that growth.

It is a rough estimate, but if you use the correlation of Freezing Degrees Day (FDD) with ice thickness, you need ~5500 FDD to go to 2m first year ice, and ~3500 FDD to go to 1.5 meters. October is usually worth ~300 to ~400 FDD in the Arctic, so it can make a significant dent into the ice growth.
To give some more numbers, for Ostrov kotel'nyj for example. Mean temperature from 1st of October to 30th of April over the last 10 years (2010-2019) was -20.8°C, which is about 4400 - 4500 FDD. If you count from the 1st of November, this leads to 4100 - 4200 FDD. And if you ignore November and start the ice thickening the 1st of December, it makes only 3800 - 3900 FDD. This is ignoring the risk that oceanic heat flux could be strong enough this winter to weaken this correlation. If ice growth does not start in a hurry on the Siberian side, the winter would probably not be able to fully erase the memory of this melting season. Which is a great peril, as up to the last years, winter was always cold and long enough to at least bring Arctic back to some kind of a "2m FYI" state, helping to stabilize the system.

5
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 23, 2020, 07:17:53 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

On the following days, 2019 is going to have several increases of more than 200K km2. As a result, on October 27th, the year 2016 starts having the lead as the lowest on record.

For 2020 to have a difference of less than one million km2 versus 2016, 2020 needs to have an average increase of more than 112.5K km2 until August October 27.

Will 2020 have this average increase? If it does not have it, then on August October 27th, the year 2020 will be more than one million km2 lower than any other year on record.

Edit:
October** JCG
Thanks

6
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 23, 2020, 05:36:23 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

October 22nd, 2020:
     5,263,107 km2, an increase of 70,966 km2.
     2020 is the lowest on record on this date.
     Highlighted the 5 years with a daily lowest min in September. In million km2:
     [ 1) 2012: 3.18,  2) 2020: 3.55,  3) 2019: 3.96,  4) 2016: 4.02  &  5) 2007: 4.07 ].
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent.

7
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 10:27:48 PM »
Climate reanalyzer does not foresee 2m temperatures dropping too much over the next ten days. Because some colors are dithered (for print!?!), the correspondence with the color bar is poor. Accurate tick marks cannot be put on the color bar because its pixel width is not an integral multiple of degrees. These errors degrade expensively acquired data so need to be fixed.
     The brain and 10 nimble fingers that singlehandedly (correction: 10 fingers = 2 hands) operates Climate Reanalyzer is aware of your critique.  The reason for dithering the color scales is because for the weather forecast animations it reduces file download size by a factor of 6X.  The file sizes are not so large as to matter for folks on an unlimited-data high-speed connection, but for people on a slower (or data-metered) connection (DSL was mentioned as a slower connection, and smartphone internet is an example of a metered connection), the file size does matter. 

    That person also mentioned that for stand-alone images, dithering the color scale may not be necessary so a possible change will be investigated.  Suggestions are well received, just remember that while CR may look like some well-funded institutionalized juggernaut, it really is a part-time operation by one person with a vision, programming skill, and committment who built something nobody else (including well-funded institutionalized juggernauts) had gotten around to doing, and done while juggling multiple other responsibilities and deadlines, including a recurring requirement for periods away from the keyboard to eat, sleep and other aspects of life.

8
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 10:26:06 PM »
Quote
freezing-degree-days? by region
Would it be easier and more informative just to query nullschool very three hours for the next five days at a handful of representative locations? Or drop a time series of screenshots onto a contouring tool? FDD is not likely to have the correct freezing temperature for the given surface salinity nor current open water as a region nor go forward in time. It's the kind of thing you would see with associated with the 80ºN DMI graph. Why, when 2m ave temperature maps are readily available?

http://psc.apl.washington.edu/nonwp_projects/landfast_ice/freezing.php

9
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 09:16:22 PM »
Quote
runaway feedbacK? much of Siberian side sea ice could end the freezing season in a very fragile state leading to earlier breakup and melt in 2021. A few days weeks late then catch-up with really fast refreeze (even though graphs of past years don't show this behavior)?
The SST will be nowhere near freezing by the end of the month; indeed air temperatures at -3 aren't cold enough to even move the needle. It takes much deeper longer cold to lower water temperature from +1ºC enough to set the stage at -1.8º for a flash freeze especially if the upper 10m of water is in play (not talking here about a micron at the surface).

The weather system over the next 120 hrs will be bringing in a fair amount of TCW (total cloud water). This again is not conducive to radiative cooling.

I'm wondering if the TransPolar Drift will set up late or perhaps hardly at all. This amount and location of open water heat may feed back on the atmospheric pressure pattern to some extent, undercutting what is needed for persistent TPD winds. If so, export out the Fram would be diminished, mostly to what ice is in the intake funnel now.

Alternatively, since Fram export stopped back in mid-May along with no garlic press and only a quarter turn Beaufort Gyre, something at a much larger atmospheric scale has changed, with late open water only having a secondary effect.

Where is nullschool getting its SST and TCW values from or rather, are there other sources that might be better or at least independent? Hard to say: multiple sources are listed for SST; none for TCW! The latter may be derived from Band 7 (2.1 μm) on Modis where it is called Cloud Water Path at WorldView

10
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 05:32:43 PM »
Animation of the extent and distribution of ice for October 21st.
(Click to play)

11
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 22, 2020, 11:34:18 AM »
October 17-21.

2019.

12
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 20, 2020, 08:37:15 AM »
October 15-19.

2019.

13
Arctic sea ice / Re: 2020/21 Freezing Season Predictions
« on: October 19, 2020, 03:41:00 PM »
A-Team's Tale of Two halves" - observations (continued)

I attach the sea ice extent and area graphs of the Central Arctic region - 3.224 million km2. Extent is 150k less than 2012, and 200k less than the 2010's average. Area is 2nd lowest, 2016 lowest.
The questions are - how slow to freeze and will freezing be complete?

And a prediction, NSIDC October average extent will be at least a record low by 250k, at leat 750k km2 (9 years) lower than the linear trend value.

Will November be the catch-up month? (or December, or like 2016, not at all?)


14
Arctic sea ice / Re: 2020/21 Freezing Season Predictions
« on: October 19, 2020, 03:14:11 PM »
A-Team's Tale of Two halves" - observations (continued)

As the freezing of the Beaufort completes, and even if the Chukchi freeze continues to be fast, then any further delay to freezing of the High Arctic seas from the ESS to the Barents is going to push Arctic sea ice extent and area further into uncharted territory.

The SST anomalies map above show that there is plenty of above average surface ocean heat, and A-team plus others convince me, at any rate, a compromised Halocline makes ocean heat at greater depth available to resist surface freeze.

Certainly the extent graphs for the Barents, Kara and Laptev show zero extent increases, while for the ESS extent growth is slow.

15
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 19, 2020, 03:43:10 AM »
Freeze-up is still going very slowly and asymmetrically, with the 'lower half' more or less normal and the 'upper half' on the Siberian side still stalled. The first two images below measure the disappearance of open water using pixel counts on AMSR2_AWI.

Because of the over-weighting brought in by the Beaufort, it is more instructive to measure the upper half separately, defined here by a line between Utqiagvik and eastern NovZem. The light blue data show not quite 7% loss of open water during the first 17 days of October.

Looking now at sea surface temperature, mixed layer depth, and surface salinity at the revolutionary new CMEMS-Lobelia tool, this unprecedented situation seems likely to continue well into November where it will be even farther outside natural variation than ever, consistent with the zonal vertical mixing data, marine dominance and tipping point analysis described in Polyakov 2019, 2020.

Atlantification of the Laptev has been slowly underway for decades according to those two papers (and 60 earlier journal articles cited) but de-stratification has gotten to the point where AW heat nearer the surface is seriously affecting the ability of fall weather to form ice. The Laptev will freeze over at some point but the ice formed will be thinner, weaker, brine-pocketed and more mobile by the beginning of melt season. We have no idea if, when and where Transpolar Drift winds will set up this fall but the combination could lead to a damaging trend.

https://tinyurl.com/y6zvqdwa

Technical note: the sea surface temperature uses kelvin in which system the freezing point of 32 psu seawater is 271.35. The display bound were then set ±7 around that; these work very similar to Nasa's worldview 'squeeze palette'. Then a divergent palette was selected, causing middle white to be the freezing point and blue/red colors to be the departure. Per NSIDC, each five units of change in salinity affect the freezing point by 0.28ºC so only very small errors are introduced over the current range of open water Arctic salinities. Grayscale salinities were contoured with the G'MIC filter in Gimp.

16
Arctic sea ice / Re: 365 day average extent poll
« on: October 18, 2020, 06:49:09 PM »
Getting to be very interesting again...

click an image to make it bigger

17
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 18, 2020, 11:19:13 AM »
  The real story will play out in the changes we are going to see in winter weather in the northern hemisphere....  I think we are about to see him emerge.


I think the Siberian seas are going through Hudsonization: from now on they will quickly melt out in June/July and then stay open for long and then suddenly freeze over in a short timeframe (2-3 weeks) during November or early December.

how this will change NH winters is anyone's guess
I think you are a bit behind the curve. Winter sea ice is now looking vulnerable.

The Barents has already lost half its winter sea ice compared with the 1980's, and even that is looking vulnerable.

The Kara sea freeze continues into January / February and in some years does not fully freeze up.

And the same to a lesser extent with the Laptev & ESS.



18
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 18, 2020, 08:52:35 AM »
October 13-17.

2019.

19
Antarctica / Re: Sea Ice Extent around Antarctica
« on: October 14, 2020, 03:50:02 PM »
Antarctica ice is at the middle of the satellite record, maybe even above average. Is the southern ice area/extent immune to the early AGW we have had?

I believe an argument is that the sea ice is protected by cold and non-saline meltwater from the Antarctic continent. And the more the continent melts due to global warming, the more the sea ice is protected. So this leads to the sea ice being in equilibrium regardless of whether the global temperature goes up or down, at least up to a point. We can see something similar happening around Greenland as well: https://en.wikipedia.org/wiki/Cold_blob_(North_Atlantic)

20
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 14, 2020, 06:10:39 AM »
October 9-13.

2019.

21
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 14, 2020, 12:59:44 AM »
Quote
the ice edge is a baroclinic zone --> clouds --> heat retained
Right. Here's a very nice display of historic October extent on the Siberian side that really brings out the unprecedented situation of the current season. The trend is to open earlier, open more, freeze later in this region of the Arctic Ocean.

Yet another fabulous graphic from @zlabe ... such an effective color scheme! Needs an inset map that defines 'Siberian Arctic' though. See above for closely related nice graphic from Geronto.)

22
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 13, 2020, 10:58:55 PM »
Quote
No idea, I’d say it’s too cold
I would say it's far too warm between the ice pack and the entire Siberian side to even be considering refreezing inroads by Nov 1st. The southern limit of ice has hardly budged since Oct 1st (magenta line) so still has 1200 km to go. The sea surface temperature anomalies are remarkable today and even out nine days to Oct 22nd, per Mercator Ocean.

An immense volume of warm water is still several degrees above the freezing point of salt water from the surface to a depth of 30+m, again out to Oct 22nd, making for some 90,000 cubic km of sea water needing to be cooled (if vertically mixed) by air having only a thousandth the specific heat capacity.

A delayed freeze has significant consequences in terms of thinner, brine pockety ice by spring like it did last year in the wake of the extreme TransPolar Drift

The Chukchi is even slated to get warmer towards the end of the month from incoming advection of yet warmer waters from the Bering Sea. At this rate, the southern Chukchi will remain open water into early or even mid January.

Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean
IV Polyakov, T Rippeth et al
J. Climate (2020) 33 (18): 8107–8123.
https://journals.ametsoc.org/jcli/article/33/18/8107/353233 free full

"The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback."

Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean
IV Polyakov et al
Science  21 Apr 2017
https://science.sciencemag.org/content/356/6335/285.full  free full

Arctic sea ice is being increasingly melted from below by warming Atlantic water
Tom Rippeth  Prof Physical Oceanography, Bangor ME
September 18, 2020  popularization by co-author of two papers above
https://theconversation.com/arctic-sea-ice-is-being-increasingly-melted-from-below-by-warming-atlantic-water-144106

"What’s causing this decline in minimum sea ice extent? The short answer is our changing climate. But the more specific answer is that Arctic sea ice is increasingly being thinned not just by warm air from above but by ever-warmer waters from below.

In fact, in a recently published scientific study my colleagues and I looked at why sea ice was melting in the eastern Arctic Ocean and showed that the influence of heat from the interior of the ocean has now overtaken the influence of the atmosphere.

While atmospheric heat is the dominant reason for melting in the summer, it has little influence during the cold dark polar winter. However, the ocean warms the ice from below year-round. Our new research shows that this influence has more than doubled over the past decade or so and is now equivalent to the melting of nearly a meter thickness of sea ice each year.

Further to the east, this warm water has been isolated from the sea surface and so sea ice by a layer of colder, fresher water. However, as the heat blob is getting warmer and moving closer to the surface its influence is now spreading eastwards through the Arctic.

In a second scientific paper we showed that currents in the upper Arctic ocean were increasing, which when combined with declining sea ice and the weakening of the boundaries between layers of warm and cold water, was potentially stirring more warm water from the heat blob towards the surface. The combined impact is a new back and forth relationship between sea ice and ocean heat which could lead to a new ocean climate state in the eastern Arctic Ocean."

23
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 10, 2020, 05:09:10 PM »
Looking at the average sea level pressure anomaly as a proxy for clearer skies during the peak AWP dates in the Laptev / ESS (~6/15-8/1), lines up decently with the large SST anomaly there now. Will be interesting to see what happens there over the next month.

24
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 10, 2020, 07:38:25 AM »
October 5-9.

2019.

25
The politics / Re: The Alt Right
« on: October 09, 2020, 11:49:15 AM »
Violence is the logical conclusion to an ideology of hate.

Take it as you will.

26
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 08, 2020, 08:16:36 PM »
CMEMS sea ice forecast shows almost no growth over the next week. Should it come off, record lows, and by huge margins, should be expected soon.

Below is a comparison between 2012 and 2020, with AMSR2 data to the 7th for 2020, and CMEMS for 8th to 14th.

27
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 08, 2020, 07:27:19 AM »
October 3-7.

2019.

28
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: October 07, 2020, 03:54:47 PM »
As expected the last piece of the Cork3 calved with other icebergs behind (indicated with a star).
Animation based on the images of 01/10 and 07/10.

Click to animate

29
Science / Re: Trends in atmospheric CH4
« on: October 06, 2020, 08:35:52 PM »
Here is the latest monthly average of Mauna Loa CH4 concentration:

June 2020:     1872.2 ppb
June 2019:     1858.8 ppb
Last updated: October 05, 2020

This is an annual increase of 13.4 ppb. This is the highest annual increase since February 2015!

I set an index = 100 for the 1980 average [1601.2 ppb]. June 2020 is at 116.9 compared to that index.

30
Arctic sea ice / Re: 365 day average extent poll
« on: October 05, 2020, 01:07:54 PM »
A 2020 record low 365 day minimum still in play.

A small milestone just passed. In late 2019 the progress towards a record low petered out on the 6th December at a 365 day average of 9.751 million km2. The 4/10/2020 365 day average is just  below 9.750 million km2.


31
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 05, 2020, 05:35:30 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

October 4th, 2020:
     4,223,302 km2, an increase of 17,665 km2.
     2020 is 2nd lowest on record on this date.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent.

32
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 04, 2020, 10:35:23 PM »
The same as above, but split based on the dates mentioned by Oren.
So we've 1979-1992, 1993-2006 and 2007-2020.
And a final one with all of the years.

I'll work on actually doing some actual analysis of these later in the week when I've some more time.

EDIT: Just spotted a mistake in the final image... just a sec Fixed! Though the images may be in the wrong order now. Oh well.

33
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 04, 2020, 12:47:33 PM »
Images and animation for today

34
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 04, 2020, 07:38:03 AM »
September 29 - October 3.

2019.

35
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 03, 2020, 02:42:29 PM »
NSIDC data
The Central Arctic Sea (CAS) & ESS graphs are attached. Some of the CAS increase is from freeze, some from ice drift from the ESS.

Note that the graph posted by Uniquorn above is of the CAB, area 4.4 million km2, which is 1.2 million km2 greater than the Central Arctic Sea from NSIDC.

36
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 03, 2020, 10:14:10 AM »
BFTV, great visualization. May I make a few suggestions:
* As headline numbers have been "fake stable" since 2007, I suggest to do another version, of 2007-2020 only.
* As monthly averages often hide interesting details, I suggest to do it with daily data.
* As the end of September contains a lot of new thin ice, I suggest to do this with data for the 1st-10th of September only. This will give the probability of an ice cover close to the minimum in recent years.
* So the map would be made up of 14 years x 10 days each, and maximal rating would be 140.
* I still think the highest rank ("never had open water") should be white and all the rest a graded color scale.

* While I'm at it, it would be quite interesting to have the same visualization for other seasonal periods, for example 1-10th of August, of July, June. Each of these will answer a different question but in the same effective method. And it fits with A-Tean's discussion of early open water and its effects.

As a comparison, make another 1-10th Sep map for 1979-1992, before the ice began its serious decline. The two maps side by side will tell the story of the change that took place in the Arctic, and how some regions with perrenial ice cover became seasonally ice free, statistically speaking.

I realize what I wrote above is a load of work. Words are easy... but I appreciate any analysis you can provide along these lines. I have long dreamed of making these myself, but my graphic and netcdf skills are very poor unfortunately.

37
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 02, 2020, 07:18:06 PM »
Playing around with some more data viz stuff.
So below is the September sea ice extent persistence. Basically, it's like stacking the average September sea ice extent for every year from 1979 to 2020 on top of each other.
Where sea ice is present in every year, the pixel value is 42 (white in the image).
Where it's present in 20 of the years, it gets a pixel values of 20 (light green)
Where it was only present in one year, it gets a value of 1 (dark orange)
And everything in between!

I'm open to suggestions on how best to display this data. I plan on doing the same for all other months too

38
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 02, 2020, 05:33:16 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

October 1st, 2020:
     4,164,656 km2, an increase of 24,445 km2.
     2020 is 2nd lowest on record on this date.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent.

39
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: October 01, 2020, 02:37:25 PM »
NSIDC Total Area as at 30-Sep-2020 (5 day trailing average) 3,079,527 KM2         
         
Total Area         
 3,079,527    km2      
-613,541    km2   <   2010's average.
-495,903    km2   <   2019
-1,409,652    km2   <   2000's average.
         
Total Change    23    k   gain
Peripheral Seas    8    k   gain
Central Seas___    15    k   gain
         
Peripheral Seas         
Okhotsk______   -0    k   loss
Bering _______    0    k   gain
Hudson Bay___    0    k   gain
Baffin  Bay____    0    k   gain
St Lawrence___    -    k   loss
Greenland____    8    k   gain
Barents ______   -0    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -1    k   loss
Beaufort_____    11    k   gain
CAA_________    8    k   gain
East Siberian__   -7    k   loss
Central Arctic_    5    k   gain
Laptev_______   -0    k   loss
Kara_________   -1    k   loss
         
Sea ice area gain on this day 23 k, 30 k less than the 2010's average gain of 53 k         
         
- 2020 area is at position #2 in the satellite record.         
- 2020 Area is 614 k less than the 2010's average         
- 2020 Area is 1,410 k less than the 2000's average         
- 2020 Area is 469 k less than 2016         
- 2020 Area is 496 k less than 2019          
- 2020 Area is 310 k more than 2012         
___________________________________________         
NSIDC Total EXTENT as at 30-Sep-2020 (5 day trailing average) 4,247,390 KM2         
         
NSIDC Sea ice EXTENT gain on this day 34 k, 20 k less than the 2010's average gain of 54k         
         
- 2020 EXTENT is at position #2 in the satellite record.         
- 2020 EXTENT is 713 k less than the 2010's average         
- 2020 EXTENT is 1,590 k less than the 2000's average         
- 2020 EXTENT is 903 k less than 2016         
- 2020 EXTENT is 339 k less than 2019          
- 2020 EXTENT is 395 k more than 2012         
___________________________________________         
Note: Click an image for full-size         

40
Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 01, 2020, 12:37:46 PM »
Here's the sea ice concentration animation for all of September. The dynamical movements are pretty interesting to watch.
There'll be a larger, better quality version going up on my twitter page in about 2.5 hours

(Large animation, ~11mb. Click to Play)

41
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 29, 2020, 11:23:00 AM »
Micro calving on the NSM side, small crisis of jealousy for his big brother.
The bay between the PIG and the Ice Rise Evan's Knoll is not only getting deeper, it's getting wider.
Animation based on low resolution images of yesterday and today.

42
Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 29, 2020, 10:56:55 AM »
And the latest images and animation.

43
Arctic sea ice / Re: The 2020 melting season
« on: September 28, 2020, 09:44:17 PM »
2020, 2018, 2015, 2012, and 2009. Roughly the same days, similar location.

44
Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 28, 2020, 04:14:58 PM »
BFTV - I know I have said this before but these three images and the one GIF are absolutely wonderful. Not sure what you could add that would provide anymore insight.

Don't know how long it takes you to put these together but thank you.

Combined with the temperature and wind animations provided by Freegrass makes this thread a delight to visit.

It would be really nice if these strong southerlies coming off of Siberia would go away.

45
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 28, 2020, 02:25:22 PM »
NSIDC data
The graphs show the contrast between the Central Arctic Sea & the Beaufort Sea

46
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 28, 2020, 12:54:11 PM »
Here is the 6-day GIF of the calving.  High resolution, but low contrast.

47
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 28, 2020, 12:41:04 PM »
And we even have a high-resolution image of P2's calving  8)

48
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 28, 2020, 12:08:51 PM »
I modified the image of my previous post (2547), containing only the lines related to the main calvings, and replacing the front line on 20/09 with today's front line  ;)

click to zoom in

Image update: I had forgotten to change the date in the image
>:(

49
Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 28, 2020, 10:34:47 AM »
Today's images and animation.
Some big losses around the Chukchi region the last 2 days with southerlies dominating here. This looks likely to continue for the coming week, so definitely an area worth watching.

50
Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 28, 2020, 07:09:48 AM »
September 23-27.

2019.

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