Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - grixm

Pages: [1] 2
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: May 23, 2020, 11:33:20 AM »
Sometimes the PIG is very fast...  :)

Arctic sea ice / Re: DMI Volume
« on: May 07, 2020, 09:11:42 PM »
They use CICE,  the current version of which was released on March 16th, 2020.

In the absence of any statement to the contrary, I assume that they keep their code up to date.

Linking DMI & GRACE-FO data

GRACE-FO gives us the changes  in the NET MASS BALANCE of Greenland.
DMI now gives us the change in surface Mass Balance (SMB)

So we now have a simple equation.

GROSS MASS Change = NET MASS loss (gain) + SMB gain (loss), and that mass change is (almost) always a mass loss.

The attached table and graph shows that the gross mass loss increases every month - even in winter. i.e. glacial melt, mostly from marine-terminating glaciers continues all winter by not a small amount.
ps: If DMI give data for years before 2018 (2017-18 were the years of no or sporadic GRACE data) then the table & graph can be extended backwards).

Greenland and Arctic Circle / Re: Greenland 2020 Melting Season
« on: April 29, 2020, 11:45:07 AM »
It is already a normally dry place and this winter there hasn't been much snow.
Little snow that the wind, a little sublimation and a little melting have probably already made disappear in some places of the glacier, probably letting the layer of the previous year appear in some places.
Even if there were only a few days just above 0°, which already seems exceptional to me, the glacier is at 1000 m of altitude, I am talking about a small melting because of the lateral valley, in the foreground, at the bottom of the picture, a valley that loses all the snow at the end of the season and whose gray spot doesn't seem to me to have any other justification.

This camera is very good to show us the dirty state in which the NE coast of Greenland is this year.
The image of the surroundings of the Fraya Glacier below shows us moreover that there was an important melting at sea level (0 m of altitude), as well as deposits of dust carried by the wind on the sea ice.

Attached :
> Reminder of the anomalies
> the surroundings of the Freya Glacier
> a zoom on the Freya Glacier
> a zoom on the area of melting and dust deposition on the sea ice

Antarctica / Re: PIG has calved
« on: April 27, 2020, 12:34:09 PM »
I accidentally found this NASA photo of the crescent in his childhood.

I thought it was pretty and I post it.

click to zoom in

Antarctica / Re: Antarctic Ice Sheet
« on: April 15, 2020, 02:39:21 PM »
Attached are AIS Mass Loss Graphs to mid-Feb 2020 as calculated by GRACE-FO.

Total mass loss 521 GT, of which half was in the western sector ( basins 19-25 ), see map attached. That equates to a 1.44 mm sea level rise (9.5 mm since 2002)

You may remember that surface melt was at a record high from mid-November 2019 to February 2020. Over 370 GT of that annual mass loss happened in the one month December to January.

Winter has arrived in the Antarctic, only question now is of mass gain this year c.f. the average?

data source :-

Arctic sea ice / Re: The 2020 melting season
« on: April 15, 2020, 06:20:27 AM »
I don't get it. How can this scale be in cm? Shouldn't that be decimeter? 72 cm is less than a meter. 70 dm is 7m.
Not much snow in Siberia, is there? But I'm pretty sure that's more than 2 cm...

Dr. Sean Birkel (who singlehandedly conceived, built, and runs Climate Reanalyzer) sent me this reply about the legend on the snow depth map:
"The plotted units were inches, while the title showed cm.  Found the plotted values are in cm set to a cm specific color scale."

   Thus, before the correction the snow depth indicated was only 40% of the actual.  Now corrected.

Arctic sea ice / Re: River ice
« on: April 09, 2020, 10:01:59 PM »
As for old averages, I found this map. Hard to see but better than nothing. Dates was calculated in 1995.

The forum / Re: Who would like to take over the ASIF?
« on: April 09, 2020, 08:22:42 PM »
If we are to have rules, I'd like to see clearer definitions.

2. Do not post "fake-news"

Already debunked information is not allowed on the forum. Climate change denialism is strictly forbidden.

Define the terms "fake," "debunking" and "denialism" ? For example, I have seen perfectly valid arguments called "denialism" on this forum.

3. Do not post “offensive” posts, links or images

Any material which constitutes defamation, harassment, or abuse is strictly prohibited. Material that is sexually or otherwise obscene, racist, or otherwise overly discriminatory is not permitted.

Define  "offensive," "defamation," "harassment," "obscene," "racist" and "disriminatory" ?

In the past Neven ran this forum with no explicit rules and used his judgement. I think that mostly worked, people went along because he started the forum and owns it. Replacing him with another dictator might work, as long as the dictator remained benevolent.

I would suggest taking a vote on new dictator(s) and spelling out a procedure for removal. Of course, that brings up other issues such as term limits, re-elections, campaigning limits ...

Perhaps Neven should have the power to appoint and remove sub-dictators instead of elections. As in political elections, those who want the job are sometimes exactly the people who should not be allowed to have it.


Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: April 09, 2020, 03:57:05 AM »
Single year and Cumulative probabilities for a ZERO volume year (as estimated in previous post).  Zero volume is unrealistic and the strictest possible definition for a BOE, but we have to have some criterion to estimate a date for BOE.

   Single year      Cum chance of first,
   chance of 0 Vol.     0 Vol. year

2020       3.0%           3.0%
2021       3.6%           6.5%
2022       4.3%         10.5%
2023       5.1%         15.1%
2024       5.9%         20.1%
2025       6.9%         25.6%
2026       7.9%         31.5%
2027       9.0%         37.7%
2028     10.2%         44.1%
2029     11.5%         50.5%
2030     12.8%         56.9%
2031     14.2%         63.0%
2032     15.7%         68.8%
2033     17.2%         74.2%
2034     18.8%         79.0%
2035     20.4%         83.3%
2036     22.0%         87.0%
2037     23.6%         90.0%
2038     25.2%         92.6%
2039     26.8%         94.6%
2040     28.4%         96.1%

Arctic sea ice / Re: The 2020 melting season
« on: April 03, 2020, 01:46:48 PM »
Around this time of year I usually take a screenshot of the ESRL Ice thickness assessment. Here are the years 2018, 2019 compared with forecast thickness 7th April 2020. (not on exact same dates but within +/- 1 week).

It does n't augur well for the coming summer.

The legend is the same for each chart with max pink colour indicating thickness of 1.6m or more. For resistence against the Arctic melt season you would be hoping for pink colour spread across the whole Arctic by now. But we are far from that.

Four areas in particular have thicknesses a lot lower than previous years:

1. Kara

Very thin and expect it will melt out quickly this year. Maybe not as crucial as other areas as it usually melts out every year anyway. Having said that an early melt would not be good for preserving ice in the main basin.

2. Polarstern

(dubbed this area - after where the Polarstern research vessel started out last Autumn). This area is near the heart of the basin and is thin. As much of the good ice heads south into the Fram, outlook for this area is not good at all. Could we see the ice edge retreat back to the pole this year with most of the ice only on the American side and maybe a typical arm heading out towards the ESS ?

3. Western Beaufort/Northern Chukchi

Thinner than usual. Legacy of late freeze ups, Pacific infiltration. This century these areas melt out every year but like the Kara an early melt out would make for an aggressive melt attack on the Basin.

4. Laptev

A lot thinner than usual. Legacy of the record mild winter over Russia. Expect an early appearance of the Laptev polynya and maybe eventually melting back to the pole ?

Antarctica / Re: Thwaites Glacier Discussion
« on: March 25, 2020, 11:39:32 PM »
The fast sea ice off of Thwaites Tongue shifted today.  The Tongue has been weakening this past season, but has been held in place this annual ice that is usually held "fast" to grounded icebergs.
Typically every 3 or 4 years, the fast ice is substantially reduced which allows the melange of loose icebergs to float off, substantially changing the shape of the Thwaites Tongue.  This often happens in March or April near the sea ice minimum.  The last time this happened was last year in 2019.  Up until yesterday, it would have seemed that it was unlikely to happen in 2020.

The GIF below show the last three days.  The mass of ice floes on the left (North) moves around quite a bit with the current and winds while the fast ice to the right (South) is firmly attached to a number of grounded icebergs and protected by the smaller bay around it.

Why the fast ice moved today is unclear.  Did it freeze to the ice floes and get pulled along?  Were they both pushed by the same wind and/or current and today was just they day that it broke free (after thawing all Summer.)

Will this continue tomorrow, maybe into April?  It is certainly hard to say.  What is clear is that the Tongue is extremely vulnerable and at high risk if more fast ice continues to break up.  The icebergs that are normally locked frozen together to form the Tongue have had a rough Summer.  The Northern end has seen a general spreading and separation since last Winter.  The Western side has sheared off after encountering an underwater peak.  To the East, the melange between the Tongue and the Thwaites Eastern Ice Shelf has been blocked behind a 10km long "cork" that may have finally broken free.  Details of all of these can be found above in this thread.  I will continue to keep a close eye on the fast ice and have my fingers crossed.

Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: March 17, 2020, 09:14:08 PM »
update on the low concentration ice north of greenland using Kaleschke SIC leads. ctr

The situation at Petermann so far in 2020:

Antarctica / Re: Thwaites Glacier Discussion
« on: February 16, 2020, 05:51:16 AM »
This tweet has a very nice 5+ year GIF of Thwaites showing quite a bit of detail.  Much better than anything I've seen for that timeframe.

Antarctica / Re: Antarctic Icebergs
« on: February 15, 2020, 08:37:31 PM »
My "pet Iceberg" B-22 in Amundsen Sea (NW of Thwaites Gl.) is on the move again. In the last two weeks it moved by approx. 1.5 km in WNW direction (identified on its S edge). A full evaluation of its movement (at all edges of B-22) is not possible, because the latest Sentinel picture is partly cloudy.
Anyway, this WNW movement increases the area of open water between it and the ice mélange further south. Sea ice in that area also slowly erodes, but this erosion process is much too slow to reach Thwaites Ice Tongue in this fading austral summer.

Antarctica / Re: Getz Ice Shelf Discussion
« on: February 14, 2020, 07:43:56 PM »
Here's a map of Antarctica.  Getz is about midway between PIG-Thwaites and Ross.  (I had to look it up).

Consequences / Re: Chinese coronavirus
« on: February 14, 2020, 11:58:55 AM »
Whenever I have this argument I like to point out at sickle cell anemia. It only affects people of African descent. There are many more diseases that are specific to the evolution of individuals of a particular descent and not general to the human race. Nurture has a lot to do with it too.

Sadly, dumb fearful people (read racists) everywhere take these differences as some sort of advantage or flaw, when they are merely slight differences.

I refuse to deny physical reality for the sake of political correctness.

Antarctica / Crosson and Dotson Ice Shelves Discussion
« on: February 13, 2020, 07:18:19 PM »
PIIS has pulled all attention in the last weeks, but a few 100 km west another ice shelf had a major calving event.
Between Feb 1 and Feb 11 a part of the Dotson Ice Shelf lost a 25*3 km piece of ice. The days in-between were too cloudy for an evaluation in EOSDIS, so a more exact dating is not possible.

See attached image.

Antarctica / Re: Thwaites Glacier Discussion
« on: February 06, 2020, 04:40:56 PM »
I haven't been posting many GIFs of Thwaites Tongue lately for a couple of reasons.  One having to do with the quality of the images I've been getting.  The other is that the landfast sea ice surrounding Thwaites is still firmly in place.  Sea ice in the Antarctic usually hits its minimum in March so we only have a little over a month left this season to see if anything really interesting is going to happen.  Last year the sea ice was mostly gone in February which caused a lot of icebergs to move off.

Anyhow, I saw this GIF posted on twitter this morning so I thought I would link it and give my own commentary on the happenings so far this season.

If you click on the link you will see a few things happening, that I reference in the picture below.

1.  The "cork" is apparently "recorking."  It had begun to move free, rotating clockwise, moving past an obstacle and on out to sea, but it is now hanging up again on a new iceberg pinned to the Eastern Ice Shelf and rotating counter-clockwise.  The forward motion is almost directly lined up with the resistance and it is possible that there will be no sliding past it.  One possible problem is that as the melange backs up behind the cork it could resume putting sideways (westward) pressure on the Tongue destabilizing it.

2.  In the GIF you can see the Eastern side of the Tongue is now moving faster than the Western side which means that the West continues to be blocked by the underwater peak.

3.  A new part of the rift between the Eastern and Western sides of the Tongue has widened significantly recently.  The less attached the Western side is, the more likely it will be to drift off in pieces once the sea ice gone, whether it is in this season or a subsequent one.

Antarctica / Re: PIG has calved
« on: February 02, 2020, 02:37:54 AM »
Fun fact: In 10 days, the calving front made up for the recent calving at the cork.

Arctic sea ice / Re: The 2019/2020 freezing season
« on: February 01, 2020, 10:17:25 AM »
grixm: Brilliant! Good statistics, but what's more, actual predictions to add spice to the winter dullness. Can't wait to see how February and March turn out - and of course, to match it up to the eventual September average extent.

Which brings me to a niggle: Your graph for January predicts a September average of 4.3 Mkm2 and not a September minimum of 4.3. Correct me if I am wrong! NSIDC September average for 2012 was an amazing 3.6 but both 2007 and 2019 came in at very close to 4.3.

As for the possible mechanism behind this statistically apparent correlation: The capping of excess ocean heat by an unusally rapid freeze and larger winter extent has already been mentioned. Another mechanism could be to do with weather, in two (possibly related) ways: The same winter weather that produces rapid freezing also results in stronger preconditioning come spring, or alternatively, a bigger extent at maximum increases the changes of stronger preconditioning weather in spring.

Antarctica / Re: PIG has calved
« on: January 22, 2020, 02:17:09 PM »

But you don't need that, actually. There is a repeating pattern, every 10 days for some days (the 2nd, and 7th for the PIG. Moving on the calendar when the month has 31 days of course).

Antarctica / Re: PIG has calved
« on: January 22, 2020, 02:16:17 PM »
The satellite travels in the same orbit every 10 days.

And that's why, to create animations, you have to use images with multiple intervals of 10 days!

Antarctica / Re: PIG has calved
« on: January 15, 2020, 07:57:27 PM »
Todays SAR shows, nothing happened.


Antarctica / Re: Antarctic Icebergs
« on: January 13, 2020, 03:37:35 PM »
I think this one makes it clearer with what i mean with 'underwater mountains in its way'.

This is the NASA Marple layer and yesterday's SNPP Day&Night band.

Antarctica / Re: PIG has calved
« on: January 06, 2020, 02:23:56 PM »
With Sentinel Playground you have the Sentinel 2 images
To get the Sentinel 1 images use Polar View (

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: December 02, 2019, 11:59:22 AM »
JAXA ARCTIC SEA ICE EXTENT :- 10,131,520 km2(December 1, 2019)

- Extent gain on this day 25 k, 42k less than the average gain of 67k,
- Extent gain in this freezing season to date is 6,142 k, 105 k (1.7%) MORE than the average gain to date of 6,038 k.
- Extent is 3rd lowest in the satellite record,
- Extent is 370 k more than 2016
- Extent is 132 k more than 2006

- Extent is 478 k less than 2018
- Extent is 354 k (3.4%)  less than the 2010's average.

- on average 62.0 % of extent gain for the the season done, 101 days on average to maximum.


Average remaining extent gain in the last 10 years from this date produces a maximum of 13.87 million km2, below the lowest in the satellite record by 0.01 million km2.
Ice Gain Outlook??

Diminishing +ve SST anomalies.
GFS says Arctic temperature anomalies in the range +1.8  to +1.0 celsius over the next 5 days, -  warmth in the Chukchi/Bering Strait, cold on the Atlantic Front. Starting Tuesday a modest blast of warmth from the Atlantic side into the Arctic Ocean - while the surrounding shores stay cold.

Winds still highly variable in strength and direction- especially at the Pacific Gateway and Atlantic Front. I continue to expect significant changes in sea ice gains (and losses) in the peripheral seas.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: December 02, 2019, 06:01:55 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

December 1st, 2019:
     10,131,520 km2, an increase of 24,863 km2.
     2019 is 3rd lowest on record.
     (In the graph: 2006, 2007, 2012 & 2016 highlighted).

Science / Re: 2019 Mauna Loa CO2 levels
« on: December 01, 2019, 05:39:16 PM »
Next week last year averaged at 408.4 ppm. Only if the daily values will start to increase more vigorously than this week, an annual increase of 2 ppm is possible. Otherwise the rate will stay at the moderate value it has been at this week.
Back to data - here is the weekly Sunday evening CO2 update from Mauna Loa

Week beginning on November 24, 2019:     410.71 ppm
Weekly value from 1 year ago:                   408.42 ppm
Weekly value from 10 years ago:                386.51 ppm
Last updated: December 1, 2019

The annual increase is back well above 2 ppm. There was no further daily average below 410 ppm, but some hourly values lay below this threshold.

Next week last year stayed around 408.5 ppm. At the moment the day-to-day changes are small, therefore an annual increase of slightly above 2 ppm is likely.

Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 14, 2019, 09:48:58 AM »

Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 19, 2019, 07:23:13 AM »
A GIF showing the freezing of the fjords northwest Greenland, taken from DMI Lincon crop.

The freezing starts around the 17th of September here.

From 06.08, many many frames, big file, click to play.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: October 06, 2019, 05:46:23 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
October 5th, 2019:
     4,556,342 km2, an increase of 22,018 km2.
     2019 is 2nd lowest on record.
     (2007, 2012 & 2016 highlighted).

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 29, 2019, 09:59:26 PM »
To produce the UH AMSR2 Graphs Wipneus uses a different mask file from NSIDC. In his analysis, the CAB area is larger by about 1.2 million km2, the surrounding seas a bit smaller and not reaching quite as far north as the NSIDC surrounding seas i.e. the Beaufort, Chukchi, ES, Laptev, Kara & CAA.
From Oren's post,2223.msg165164.html#msg165164

Wipneus AMSR2 (Cryosphere Today map)  NSIDC Regions (MASIE map)
CAB         4.48     3.22
Beaufort   0.53     0.94
Chukchi    0.61     0.83
ESS         0.95     1.3
Laptev     0.73     0.87
Kara        0.9       0.92
CAA        0.78      0.76
So the NSIDC Laptev Area & Extent graphs attached show a bit more ice remaining. However, the AMSR2 data starts in 2012 when the Japanese (?) put up the new satellite with the bigger dish that gives so much better resolution. So to see trends back to the 1980's, NSIDC data is the only way. (Unless JAXA provides readily accessible data by regional seas).

The graphs show the extent to which summer sea ice has dramatically reduced during the last 40 years.
Having more than one set of boundaries is a pain - and happens elsewhere. There are 2 accepted definitions of the Greenland and Antarctic drainage basins - nearly but not quite the same. And I have 2 sets of data that I cannot combine because of it.

Science / Re: 2019 Mauna Loa CO2 levels
« on: September 22, 2019, 06:50:17 PM »
Last year next week was a bit higher than this week. With a further small and slow decline in the next days we will (hopefully) see an annual increase slightly below 3 ppm.
There are the actual values, now showing an annual increase below 3 ppm:
Week beginning on September 15, 2019:     408.50 ppm
Weekly value from 1 year ago:               405.67 ppm
Weekly value from 10 years ago:            384.59 ppm
Last updated: September 22, 2019

Next week last year was a bit lower than this week. With slightly decreasing CO2 concentrations in the next days we will manage to keep the annual increase below 3 ppm again.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 18, 2019, 09:31:24 AM »
According to the JAXA-Dataset, to date 2019 has:
  • 49 days of being lowest
  • 141 days in lowest 2
  • 162 days in lowest 3
after 260 days having passed this year.

Arctic sea ice / Re: The Freezing Season For Dummies
« on: September 15, 2019, 05:53:02 PM »
Apartheid introduced at the arctic sea ice forum.

Arctic sea ice / Re: The 2019 melting season
« on: September 09, 2019, 03:14:10 PM »
Problem solved! I will be posting my Nullschool graphics here from now on. Feel free to post your own!,2905.0.html

Science / Re: Satellite News
« on: August 31, 2019, 07:53:32 PM »
What a Tweet Tells Us About US Spy Satellites

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 07, 2019, 03:43:14 PM »
NSIDC Total Area as at 6 August 2019 (5 day trailing average)  3,666,090 km2

The 7 day turnaround has stopped.
On this day area loss close to average.
Total Area         
 3,666,090    km2      
-529,881    km2   <   2010's average.
-513,403    km2   <   2018
-1,316,789    km2   <   2000's average.
Total Area Change   -65    k   loss
Peripheral Seas   -7    k   loss
Central Seas__   -58    k   loss
Other Seas___    0    k   gain
Peripheral Seas         
Bering _______    0    k   gain
Baffin  Bay____   -1    k   loss
Greenland____   -6    k   loss
Barents ______   -0    k   loss
CAB Seas         
Beaufort_____   -10    k   loss
CAA_________   -14    k   loss
East Siberian__   -18    k   loss
Central Arctic_   -10    k   loss
Kara_________   -2    k   loss
Laptev_______   -3    k   loss
Chukchi______   -1    k   loss
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___    -    k   loss
Hudson Bay___   -0    k   loss
- Area loss 65 k, 5 k MORE than the 2010's average area loss of 60 k on this day.
- Total area 2nd Lowest, 197 k LESS than 2016, and 133 k MORE than 2012.

We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On this day area loss average, close to 2016 and less than 2012 on this day.

Of note is:
- Only some of the seven seas of the High Arctic are losing seas ice area at above average daily rates.
- The Chukchi has slowed,
- The ESS & the Beaufort are losing area at a good clip,,
- The CAA should be really warm all this week again - and some rain. Also high daily melt.
- No or little Fram export - and Greenland area loss up again. This may change after a few days.
- the CAB had a low area loss and  is still above the 2010's average .

Area continues 'twixt 2012 and 2016.

Arctic sea ice / Re: The 2019 melting season
« on: July 29, 2019, 08:35:16 AM »
There's no Point in posting HYCOM, as they switched from ArCc to Glb Models since about 2017. Especially when making Comparisons.
Glb seems to indicate much less thicker Ice than the previously used ArCc Model.

Arctic sea ice / Re: The 2019 melting season
« on: July 18, 2019, 05:04:54 PM »
the value of pms .. Neven can read at his leisure and respond in kind rather than search for posts that may be 10 or 20 pages back when he returns or maty never read .. b.c.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 16, 2019, 03:16:38 PM »
NSIDC Total Area as at 15 July 2019 (5 day trailing average) 5,221,614 km2
Total Area         
 5,221,614    km2      
-603,733    km2   <   2010's average.
-712,418    km2   <   2018
-1,335,604    km2   <   2000's average.
Total Area Change   -92    k   loss
Peripheral Seas   -12    k   loss
Central Seas__   -69    k   loss
Other Seas___   -11    k   loss
Peripheral Seas         
Bering _______    0    k   gain
Baffin  Bay____   -5    k   loss
Greenland____   -3    k   loss
Barents ______   -4    k   loss
CAB Seas         
Beaufort_____   -9    k   loss
CAA_________   -9    k   loss
East Siberian__   -16    k   loss
Central Arctic_   -7    k   loss
Kara_________   -10    k   loss
Laptev_______   -6    k   loss
Chukchi______   -11    k   loss
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___    0    k   gain
Hudson Bay___   -11    k   loss

- Area loss 92 k, 11 k LESS than the 2010's average loss of 103 k on this day.
- Total area Lowest, 273 k LESS than 2016, and 27 k LESS than 2012.

Area loss dipping below average, difference with 2012 narrowing, with 2016 widening.

Other Stuff
GFS  showing temperature anomalies in the range +0.9 to 0 degrees celsius over the next 10 days. Over the next 5, or even 10, days it looks like a fairly significant low sits over the central Arctic Ocean north of Central / Eastern Siberia and elsewhere a high sits in the North Atlantic and another high over Greenland. The strongish anticlockwise winds matching but opposite to the normal clockwise movement of the Beaufort Gyre are maintained, starting as northerly winds from the CAA and the North Greenland coast. Wind and rain also from the South up Baffin Bay into the CAA at least for the first few days.

What all this means for melt is.... ?
Is this weather pattern there for the long-term?

A cliff or not a cliff** See below
We are in the period of maximum daily area loss that lasts until late July.
Overall, Area losses in July to date above average.

It looks like Fram export has stalled, with most area losses in the arc from the ESS along the Russian shore and down to the Barents. The CAA is showing signs of melt strongly increasing.

It is definitely a steep downward slope

However, the ESS is not a slope, or a cliff. It is a yawning abyss, but is the yawn decreasing? YES

NSIDC 5 day Area could/would/should/will/will-not continue in pole position for about one week/two weeks/the rest of July/the entire remaining melt season (delete as applicable).
ps: Meanwhile, Extent loss was well below average. But daily extent loss just went up on this day. Switcheroo?

Arctic sea ice / Re: 2019 vs 2012
« on: July 16, 2019, 12:34:45 PM »
DMI's thickness model shows pretty different results to PIOMAS. Where PIOMAS has 2012 and 2019 pretty much tied for volume at this point, 2019 is lagging pretty far behind according to DMI: (click to play)

I asked what the difference between these models are in the PIMOAS thread and why no one seems to talk about DMI, didn't get a response.

DMI uses CICE (and HYCOM for the weather forecast), PIOMAS uses PIOMAS.

DMI is a model to predict extent, PIOMAS is a model to measure total volume. Either can be used for another purpose, but its rather more likely to be bad at it than its primary purpose.

DMI don't publish much on their model so my diagnosis of their weaknesses may miss something important and these weaknesses may not be the critical ones.

CICE is a model developed for GCMs which is portable into weather forecast models rather than climate models, and DMI isn't the only group that has had trouble keeping it numerically stable. (I reckon the stability issue probably arises from calculated salinity being extremely sensitive to measurement error in assimilated temperature.)  DMI publish on their model rather less than they tweak it, so its not possible to be sure just what they are doing at the moment, but last time I found something on it they were assimilating a large chunk of climatology as well as data.

DMI has an issue with melting momentum. They hit volume minimum too early and have a much too steep melting curve during the summer. I think this probably derives from their sea model being a weather forecast model rather than an ice melt model and heat that should be going into a near surface sea layer in June/July and getting back to the melt ice in August/September, is being put directly into melting ice.

If you use the same DMI model to compare 2012 and 2019, its probably not too misleading, but you need to be sure its a reanalysis of 2012 using the 2019 model, because otherwise you'll be looking at the difference between their 2012 model and their 2019 model rather than the ice. (and if its a big difference, you'll can't tell whether its real or whether the model is having one of the years in which it goes haywire)

Consequences / The Climatic Effects of a Blue Ocean Event
« on: July 13, 2019, 09:06:18 PM »
I have been finding it difficult to find information on the wider global impacts of a Blue Ocean Event, outside the likes of Paul Beckwith. Peter Wadhams and an odd few extremely reticent/conservative academic papers. Hopefully this topic will help bring together what knowledge there is. Impacts from the materials that I have been able to find have included:

- A collapse of the polar cell and ferrel cells with a resulting equible Northern Hemisphere climate
- A "polar cell" centred on Greenland (until that melts out) with very static jet streams and little seasonal variability
- A maritime environment in the Arctic that produces large precipitation on permafrost areas, which will then accelerate CO2/CH4 emissions
- Massive storms in the North Atlantic as the more rapid melting of Greenland creates a bigger, more intense, "cold blob" that contrasts with the warmer waters around it
- A general acceleration of climate change due to much lower Northern Hemisphere reflectivity
- More rapid melting of the Antarctic due to the climate "see-saw"
- Northward movement of the ITCZ rain belts greatly changing rainfall patterns (plus and minus) for some areas
- etc.

This is a paper I wrote on the subject a couple of years ago and its amazing how little research has been published in the interim.

Seems to generally be "the Northern Hemisphere is f***ed" with a BOE. I have started looking at real estate in Ecuador (Cuenca seems to be very nice) and the Paraguay highlands! Others insights would be much appreciated.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 08, 2019, 09:02:18 PM »
Is there any way to find out where the CAB losses are coming from?

At 2.8M km2, that bucket is ~ 1/2 of all that remains and we've lost almost 0.3M km2 in the last 2 weeks from the CAB.

Anyone with NSIDC connections?

NSIDC sea ice concentration images are here:

Here's an animation for the past 4 weeks, showing how the ice in the CAB gradually turns from white to blue.  That is mainly due to the spread of melt ponds: NSIDC sea ice area cannot really distinguish melt ponds from open water. 

Pages: [1] 2