Let us begin this month’s report from the far north with the high resolution Arctic sea ice area and extent graphs based on the University of Hamburg’s AMSR2 concentration maps:
Area is currently lowest for the date in the AMSR2 record. After briefly occupying that position extent has increased over the last few days of April due to winds causing sea ice to move in the direction of the far North Atlantic:
The Alfred Wegener Institute has now finished reanalysing their CryoSat-2/SMOS thickness data, and the resulting volume graph looks like this:
“Measured” Arctic sea ice volume is the lowest in the CryoSat-2 era as we head towards the main 2020 melting season, which in my calendar at least begins on June 1st. The PIOMAS modelled volume numbers should be released shortly.
[Edit – May 5th]
The April 30th PIOMAS gridded thickness numbers have been released, and Wipneus has worked his usual magic. By way of comparison with the AWI metric:
Obviously differing from CryoSat-2/SMOS, PIOMAS has 2020 volume a long way above 2017, in amongst a gaggle of other years.
[Edit – May 13th]
The middle of May is rapidly approaching, so let’s start to set the scene for the forthcoming melting season. First off here are the hi res AMSR2 area and extent graphs:
Extent is currently significantly above 2016 due to the recent “dispersion” mentioned above, but area is very close to an all time low for the date.
Next take a look at the current northern hemisphere snow cover anomalies from the Rutgers University Snow Lab:
Whilst there is a positive anomaly near Hudson Bay, there are significant negative anomalies across Siberia and Alaska. This does not augur well for sea ice retention along both the Northern Sea Route and Northwest Passage by September 2020.
This comes to you a couple of days early, but the clocks have just changed to British Summer Time in the once United Kingdom and there is news to impart.
JAXA Arctic sea ice extent has fallen to the lowest level for the date in their satellite era records going back to 1979. This graph shows every year since 2000:
The high resolution AMSR2 regional graphs make clear that the precipitous drop on the Pacific periphery has continued:
The current combined SMOS/SMAP Arctic sea ice “thinness” map makes clear that there is plenty more thin ice ready for melting in the Sea of Okhotsk and Baffin Bay:
There is also a large area of thin ice in the Laptev Sea, which will be interesting to watch once the 2020 melting season gets underway in earnest.
[Edit – April 1st]
Today is All Fools’ Day, but this is no joke. Thanks to the consistent polar vortex over the Northern Hemisphere winter there is currently an anomalous “ozone hole” over the North Pole. As recently described in Nature:
A vast ozone hole — probably the biggest on record in the north — has opened in the skies above the Arctic. It rivals the better-known Antarctic ozone hole that forms in the southern hemisphere each year.
Record-low ozone levels currently stretch across much of the central Arctic, covering an area about three times the size of Greenland. The hole doesn’t threaten people’s health, and will probably break apart in the coming weeks. But it is an extraordinary atmospheric phenomenon that will go down in the record books.
“From my point of view, this is the first time you can speak about a real ozone hole in the Arctic,” says Martin Dameris, an atmospheric scientist at the German Aerospace Center in Oberpfaffenhofen.
Here are the latest graphics from the “Arctic Ozone Watch” section of the NASA web site:
Observations made during the still ongoing MOSAiC expedition, have confirmed the satellite derived measurements:
This year, powerful westerly winds flowed around the North Pole and trapped cold air within a ‘polar vortex’. There was more cold air above the Arctic than in any winter recorded since 1979, says Markus Rex, an atmospheric scientist at the Alfred Wegener Institute in Potsdam, Germany. In the chilly temperatures, the high-altitude clouds formed, and the ozone-destroying reactions began.
Researchers measure ozone levels by releasing weather balloons from observing stations around the Arctic (including the Polarstern icebreaker, which is frozen in sea ice for a year-long expedition). By late March, these balloons measured a 90% drop in ozone at an altitude of 18 kilometres, which is right in the heart of the ozone layer. Where the balloons would normally measure around 3.5 parts per million of ozone, they recorded only around 0.3 parts per million, says Rex. “That beats any ozone loss we have seen in the past,” he notes.
I’ve previously conjectured about the potential effect of the strong polar vortex on Northern Hemisphere snow cover this Spring, and here’s NOAA’s current snow extent graph:
JAXA extent’s precipitous recent decline has abated, and it’s now 5th lowest for the date in the satellite era:
[Edit – April 4th]
Here’s the March 31st PIOMAS Arctic sea ice gridded thickness map:
Ice is thickening impressively against the Canadian Archipelago and North Greenland.
That is indeed the case with the PIOMAS “modelled” numbers, but is much less obvious in the latest CryoSat-2/SMOS “measured” thickness map where ice over 4 metres thick is still conspicuous by its absence North of Greenland:
[There’s] not much thick ice on the East Coast of Greenland, indicating the increase was from reduced loss through the Fram Strait?
together with the latest AARI ice age map:
[Edit – April 6th]
Here’s the latest update of our novel NRT volume metric:
I’ve applied a crude correction to the still problematic NRT data so that it at least coincides with the reanalysed data on March 14th. Whilst we await the reanalysed numbers for the rest of March and early April it looks as though Arctic sea ice volume reached at least a temporary peak on March 20th 2020.
[Edit – April 19th]
Here’s another update of our novel NRT volume metric, still incorporating my “fudge factor”:
Note also this handy hint from Stefan Hendricks on Twitter:
The reprocessed #Cryosat2 data is fine though and for the recent winter there is a corrected CS2SMOS version: ftp://ftp.awi.de/sea_ice/product/cryosat2_smos/v202_2/
Wipneus has crunched the mid month PIOMAS gridded thickness numbers. Here’s the result:
The discrepancy between the PIOMAS model and the CryoSat-2 “reality” is still very evident.
[Edit – April 25th]
With another week’s worth of reanalysed data now processed, it now seems certain that the CS2/SMOS Arctic sea ice volume maximum was 18469 km³ on April 6th:
[Edit – April 28th]
The high resolution AMSR2 area and extent metrics are now both “lowest for the date” in the AMSR2 record:
As Zack Labe has recently pointed out, in 2015 the Arctic sea ice maximum extent based on the JAXA numbers had already occurred on February 15th:
Perhaps it’s time we started paying attention this year! However the National Snow and Ice Data Center reported a significantly later date in 2015:
On February 25, 2015, Arctic sea ice extent appeared to have reached its annual maximum extent, marking the beginning of the sea ice melt season. This year’s maximum extent not only occurred early; it is also the lowest in the satellite record. However, a late season surge in ice growth is still possible.
Each year we keep track of the assorted Arctic sea ice metrics over the next month or so, and they rarely agree on the date of maximum extent, and never agree on the sea ice extent on that date! The reason for that is explained in a 2017 paper entitled “Variability and trends in the Arctic Sea ice cover: Results from different techniques“:
Reports on the sea ice cover have been provided by different institutions using basically the same set of satellite data but different techniques for estimating key parameters such as ice concentration, ice extent, and ice area. In this study, a comparison of results from four different techniques that are frequently used shows significant disagreements in the characterization of the distribution of the sea ice cover primarily in areas that have a large fraction of new ice cover or significant amount of surface melt.
In due course we’ll look at the metrics from a variety of different institutions, but let’s start with JAXA, comparing 2020 with 2015 and the 2010s average:
Extent is clearly increasing just at the moment! Will the next peak prove to be the maximum for the year or will we have to wait another month or more to find out that value, as suggested by the average?
Compare and contrast JAXA extent with Wipneus’ high resolution AMSR2 extent and area:
Perhaps the 2020 maximum area has already been reached?
[Edit – February 25th]
Or perhaps not! We’re playing mix and match this morning, since Wipneus’s new numbers haven’t been released yet. Here UH AMSR2 high resolution Arctic sea ice area from February 23rd:
Plus JAXA extent for the 24th:
[Edit – February 27th]
Tony Heller’s latest sea ice themed article claims “Normal Sea Ice Extent At Both Poles”. Hence today’s JAXA extent graph includes the averages for previous decades:
Extent is evidently increasing once again, and is even more evidently well below what passed for “normal” in the twentieth century!
Let’s also compare the Pacific periphery:
with the Atlantic side of the Arctic Ocean:
The Bering and Okhotsk Seas will be sea ice free by the time September 2020 arrives. How about the Kara, Barents and particularly Greenland Seas though?
[Edit – February 29th]
Arctic sea ice maximum volume usually occurs in April, but nonetheless let’s keep an eye on the metric that most nearly measure the “amount” of sea ice left in the Arctic in 2020. Here’s our “measured” CryoSat-2/SMOS volume metric, using reanalysed data up to February 12th:
PIOMAS “modelled” volume for February should be released soon, but getting back to extent the JAXA flavour has been setting new highs over recent days:
whereas the NSIDC’s Charctic 5 day averaged extent has not!
[Edit – March 6th]
Here’s the February PIOMAS gridded Arctic sea ice thickness map, courtesy of Wipneus on the Arctic Sea Ice Forum:
plus the traditional modelled volume graph:
As angech has pointed out elsewhere, according to the PIOMAS team:
CryoSat-2 data show total volume for February 2020 substantially lower than PIOMAS with 2020 Febuary near record low levels over the 2011-2020 period
[Edit – March 19th]
The March mid month PIOMAS numbers have been crunched by Wipneus. Here’s how things look at the moment:
For comparison purposes here’s the current CryoSat-2/SMOS Arctic sea ice thickness map:
[Edit – March 20th]
After flatlining for a long time JAXA extent has posted significant declines for two days running. There’s been no official announcement from the NSIDC as yet, but it now seems safe to conclude that there won’t be a late surge in extent similar to 2010. Here’s the current JAXA graph:
plus NSIDC’s 5 day averaged extent:
Hence the (still provisional!) maximum numbers for 2020 are:
JAXA/VISHOP AMSR2 – 14.45 million square kilometres on March 3rd
NSIDC 5 day SSMIS – 15.05 million square kilometres on March 5th
The University of Hamburg’s JAXA AMSR2 concentration data seems to have suffered an outage over the crucial period. Hopefully the gaps will be filled in due course. However more recent regional graphs reveal the following:
The recent declines in overall extent are evidently driven by declines on the Pacific periphery.
In the absence of the usual mid month PIOMAS Arctic sea ice volume update I’m being moaned at by “angech” over on Judith Curry’s “Climate Etc.” blog:
Any ideas on why PIOMAS mid month update not out, other than not wanting to show a big recovery?
Unlike any of Judy’s denizens I checked out the comparatively new merged CryoSat-2 plus SMOS thickness maps from the Alfred Wegener Institute. “Measured” rather than “modelled” data must be a good thing surely?
Just in case there’s some significant difference between the “reanalysis” and “operational” versions of that product, here is the AWI’s most recent reanalysed Arctic sea ice thickness map, for the week ending January 11th:
together with the same date from the previous two years:
Make sure to take a close look at the white areas north of Greenland and the Canadian Arctic Archipelago showing sea ice over 4 metres thick.
Over the winter of 2018/19 ASCAT revealed that there was a relentless movement of multi-year ice towards both the North Atlantic and the Beaufort Sea.
Not unexpectedly that meant that ice in the northern Barents Sea was slow to melt out in the summer of 2019:
whilst after a fast start the melt in the Beaufort Sea also suffered a “brief hiatus” in June before ultimately melting out almost completely as well:
Perhaps a significant amount of the multi-year ice that survived the winter of 2018/19 has now simply melted away in warm water, to be replaced by much less robust first year ice in the area between the North Pole and the Siberian coast? It will be very interesting to see what the next PIOMAS update in early February reveals.
[Edit – February 4th]
The next PIOMAS update referred to above has now arrived. Here’s the Polar Science Center’s graph:
Over on Climate Etc. angech is already exclaiming:
Strange it did go up a fair bit the old PIOMAS.
No publicity at the usual going down sites.
Actually it’s not at all strange, because thus far this winter the polar vortex has been remarkably well behaved. By and large cold air air has stayed in the Arctic. There hasn’t been much in the way of cold air intrusions into mid latitudes or warm air intrusions into the Arctic.
Hence it’s not at all surprising that the thickness of sea ice in the Arctic has been increasing slightly more quickly this winter than in other recent years. By way of some longer term context, here are the official Polar Science Center min/max trends:
[Edit – February 4th PM]
Wipneus has just released the January PIOMAS gridded thickness map. Here it is:
[Edit – February 5th]
As is all too frequently the case, AdR and other commenters below get very excited about trivial increases in sea ice extent without considering snow extent. One side effect of the lack of cold air outbreaks into mid latitudes so far this winter currently looks like this:
[Edit – February 6th]
The AWI and PIOMAS sea ice thickness maps above look somewhat different at first glance. That being the case, I’ve written a program to crunch the AWI numbers. Here’s the result:
The source code plus raw and processed data can be accessed via the Arctic Sea Ice Forum:
Further support for my “polar vortex” theory, from Judah Cohen no less!
I think this plot best sums up the #winter for the Northern Hemisphere –#PolarVortex strength bouncing around from near (daily) record strong to normal all winter long. One more near record strong (PV) for latter half of February. Pretty much the nail in the coffin on this winter pic.twitter.com/OiSZw07VOF
I am forced to ponder once again why the CryoSat-2/SMOS thickness “measured” numbers just above seem to be more at variance with PIOMAS in 2020 than in previous years:
[Edit – February 22nd]
Here’s another weekly NRT volume update:
This time I’ve left off the NRT data from February 6th onwards, since the “issue” referred to above obviously hasn’t been solved yet. As an added bonus here’s a graph showing the trends (or lack thereof) on 3 dates during the October to April freezing season:
Whilst we await the PIOMAS volume numbers which generally arrive around the 5th of each month, and before we look at graphs of extent, with the refreeze well under way some “measured” thickness maps are coming back! Here’s the first SMOS map this autumn:
Then of course there’s our usual Arctic wide high resolution AMSR2 area and extent graphs:
They reveal both metrics currently still second lowest (in the brief AMSR2 record) after 2012. It looks as though that may well change soon, particularly area.
The near real time NSIDC monthly extent for September is 4.32 million km². Here’s the graph:
We’re eagerly awaiting the first ice mass balance buoy “near real time” data, but for now the 2019 PIOMAS minimum volume is expected to be revealed real soon now, so:
[Edit – October 5th]
As previously perfectly predicted, the PIOMAS numbers have arrived over at the ASIF. Here’s the thickness map for the end of September:
A marginally off topic excursion down under. The NSIDC 5 day average Antarctic sea extent looks to have peaked at 18.40 million km² on September 30th:
[Edit – October 7th]
The first of the MOSAiC Expedition’s Ice Mass Balance buoys has been installed, presumably on the ice floe Polarstern is moored to. It reveals sea ice that is currently just over 1 meter thick with a sprinkling of snow on top:
P.S MOSAiC IMB buoy #3 has gone live today too:
There’s currently only 0.5 meters of ice under this one.
[Edit – October 9th]
Here’s the latest annual PIOMAS “ice cube” animation from Andy Lee Robinson:
[Edit – October 10th]
Here’s the latest DMI “high Arctic” temperature graph:
Needless to say that means the DMI Freezing Degrees Days graph is tracking the lowest readings in the DMI’s records:
[Edit – October 11th]
MOSAiC IMB buoy #2 has now been installed and is beaming back data:
The sea ice at this location is decidedly on the thin side at present. A mere 20 cm or thereabouts!
[Edit – October 12th]
The JAXA ViSHOP web site is down at the moment, so by way of a change here is the University of Bremen’s AMSR2 based extent graph instead:
2019 Arctic sea ice is extent is now once again “lowest for the date” (since AMSRx satellite records began).
[Edit – October 14th]
The JAXA/ADS/ViSHOP web site is back online after being down over the weekend, presumably due to the effects of Typhoon Hagibis:
Sure enough the Japanese flavour of AMSR2 based extent is also now “lowest for the date”.
Mike and Borge’s current position was reported yesterday as: 89°35′51″N 140°30′32″E
[Edit – October 15th]
The latest SMOS Arctic sea ice “thinness” map shows sea ice starting to form on the shores of the Laptev Sea:
[Edit – October 16th]
The Centre for Polar Observation and Monitoring (CPOM) have just published the first CryoSat-2 Arctic sea ice thickness map of the 2019/20 freezing season:
Note in particular the dark blue area north of the Canadian Arctic Archipelago.
[Edit – October 20th]
Wipneus has just crunched the October mid month PIOMAS numbers. Here are the results. Not only the modelled Arctic sea ice thickness map:
but also the Arctic sea ice volume graph:
[Edit – October 21st]
Over on Twitter Judah Cohen suggests that:
Maybe I will discuss more in the next blog but the #Arctic sea ice growth season on the North Pacific side of the Arctic is just nuts, like it is drunk! Looks unprecedented to me. This needs to be watched through the #winter. Already had 2 unprecedented winters in the Bering sea pic.twitter.com/sAVoZXgNAX
I have been trying to bring the implications of this to the attention of the denizens of Judith Curry’s “Climate Etc.” blog, thus far with remarkably little success! This is the gist of my argument:
“Summer solar heat absorption by the surface waters has increased fivefold over the same time period, chiefly because of reduced sea ice coverage.”
“The effects of an efficient local ice-albedo feedback are thus not confined to the surface ocean/sea ice heat budget but, in addition, lead to increased heat accumulation in the ocean interior that has consequences far beyond the summer season.”
“In the coming years, however, excess Beaufort Gyre halocline heat will give rise to enhanced upward heat fluxes year-round, creating compound effects on the system by slowing winter sea ice growth.”
A couple of years ago I was asked to provide “a handful of things [you] will be keeping an eye on over the next few months to judge how ‘good’ or ‘bad’ the melt is going?”
That suggests snow cover over land is close to recent lows, which is confirmed by the Rutgers University snow cover anomaly graph for April:
This year is anomalously low, but not by as much as 2012 and 2016. For completeness, here also is the current US National Ice Center snow cover map:
Moving on to melt ponds, there are plenty to be seen on the fast ice around the Mackenzie river delta:
NASA Worldview “false-color” image of the Mackenzie Delta on May 24th 2019, derived from the MODIS sensor on the Terra satellite
There also seem to be signs of some at a higher latitude off Ostrov Kotelny in the New Siberian Islands:
NASA Worldview “false-color” image of the Laptev Sea on May 23rd 2019, derived from the MODIS sensor on the Terra satellite
This year there is also a lot of open water in the Chukchi Sea, and almost no sea ice left in the Bering Sea:
Compared with 2016 at the same time of year I am compelled to say that with June 1st just around the corner the 2019 summer melting season is primed to progress more quickly.
The next obvious comparison to make is with the (in)famous year of 2012, which resulted in the lowest ever minimum extent in the satellite record. Firstly let’s look at the National Snow and Ice Data Center’s graph of Arctic sea ice extent:
Currently extent is significantly below 2012, albeit somewhat above 2016 at the same time of year. And what of melt ponds? In 2012 there was evidence of less snow cover over land and more surface water on the ice on the Siberian side of the Arctic:
NASA Worldview “false-color” image of the Eastern Arctic on May 25th 2012, derived from the MODIS sensor on the Terra satellite
Other than that Arctic sea ice in 2019 looks to be in worse shape than in 2012.
[Edit – May 27th]
We’ve established that the extent of Arctic sea ice at the end of May 2019 is less than in 2012, but something else to consider is whether that ice is currently thicker than in 2012, or not. Satellites can have a reasonable stab at measuring the area of sea ice, but the third dimension is much trickier. The European Space Agency’s CryoSat-2 satellite has been attempting to measure sea ice thickness since 2010, so let’s take at the conclusions it has reached:
Don’t forget to take a good long look at the associated uncertainties too:
At the beginning of April 2019 all the assorted Arctic sea ice extent metrics are at their respective lowest levels for the date in the satellite record. Just for a change let’s start with the JAXA/ViSHOP graph for April 1st, based on AMSR2 data:
That shows extent apparently on an inexorable decline. However the higher resolution graphs derived by Wipneus from University of Hamburg AMSR2 concentration data reveal that Arctic sea ice extent has changed little over the last couple of days, and area has even increased somewhat:
Whilst we wait for Wipneus’ latest PIOMAS thickness and volume update, here’s the gridded merged CryoSat-2/SMOS thickness data from the Finnish Meteorological Institute:
Watch this space for some other extent graphs once they’ve updated to April 1st. In particular the DMI’s version of events will be of great interest, since by way of a little All Fools Day fun I passed on the latest Arctic sea ice news to Tony Heller and the denizens of his “Deplorable Climate Science Blog” yesterday. They were not amused! By way of example, Rah solemnly informed me that:
Tony consistently has used the DMI data as his primary source on the conditions in the Arctic, while you jump to whatever source you think justifies your bias. Get a life. Arctic air temps this year so far have been running below what they were at this time last year.
This is the graph that Steve/Tony used in an attempt to make his point:
Plus the April 2nd DMI “Arctic temperature” graph:
[Edit – April 3rd]
Snow White asked Axel Schweiger nicely on Twitter, and as if by magic the PIOMAS numbers for March have been released, including gridded thickness. Wipneus has crunched them to reveal the following end of March sea ice thickness map:
plus a rather unusual volume graph:
Here’s a closeup view:
According to the PIOMAS model Arctic sea ice volume has been flatlining for the last couple of weeks, and may even have peaked already!
Meanwhile returning to 2 dimensions the decline in area has resumed:
[Edit – April 7th]
Wipneus’ UH high resolution extent fell another 129k yesterday:
Plus a close up look at the FMI merged Cryosat-2/SMOS thickness for both the Atlantic and Pacific sides of the Arctic:
Apart from the usual thick ice queueing for the Fram Strait exit there’s not a lot to prevent the comparatively swift early melt from continuing apace.
Since the FMI make the gridded data available as well as that visualisation, here’s a closer look at the Bering/Chukchi area:
There’s an awful lot of thin ice in the region ripe for rapid melting now that the sun is shining down for a rapidly increasing number of hours per day. Over on the other side of the North Pole there’s also some significant swell forecast to hit the Atlantic edge of the Arctic ice pack. Here’s the current WaveWatch III forecast for 09:00 UTC tomorrow morning:
Finally, for the moment at least, here are the current Arctic wide high resolution AMSR2 sea ice area and extent graphs:
[Edit – March 22nd]
This Sentinel 1 SAR image of the Lincoln Sea from PolarView suggests that the northern arch of the Nares Strait is breaking up once again:
It is therefore conceivable that sea ice in the Lincoln Sea will continue to break up and flow south through the Nares Strait for the entire 2018/2019 winter.
[Edit – March 23rd]
Bering Sea ice area has “rebounded” over the last few days:
and taken the Arctic wide metrics with it:
Here’s the latest Sentinel 1 SAR image of the Lincoln Sea and northern Nares Strait:
[Edit – March 24th]
The “rebound” has reversed:
With temperatures above freezing point across the Bering and Chukchi Sea forecast for tomorrow morning expect the decline in Arctic sea ice extent to accelerate:
[Edit – March 25th]
There was a 162k decline in high resolution extent yesterday:
Here also is the current state of the thick sea ice exiting the Lincoln Sea via the Nares Strait:
[Edit – March 27th]
Here’s another week’s merged CryoSat-2/SMOS thickness data from the Finnish Meteorological Institute:
[Edit – March 30th]
We’re still waiting for Wipneus’ Raspberry Pi to crunch the high resolution AMSR2 numbers, but here’s the latest from JAXA:
2019 currently in 3rd place by a whisker.
P.S. The high resolution AMSR2 numbers are out:
Area is certainly lowest for the date in the AMSR2 era. Extent will almost certainly achieve that status tomorrow. Excluding the two most peripheral seas reveals perhaps an even more worrying picture?
[Edit – March 31th]
Arctic sea ice coverage is now firmly in the “lowest extent for the date in the satellite record” category, whichever metric you care to choose:
The NSIDC 5 day average is in a “statistical tie” for first place with 2017:
March 2019 has arrived, which in recent years has proved to be by far the likeliest month to contain the maximum extent of Arctic sea ice for the year. To begin with, here’s our favourite high resolution extent graph calculated by “Wipneus” from University of Hamburg/JAXA AMSR2 data:
Hopefully you can plainly see the pronounced sharp peak towards the end of February 2019? The current maximum Arctic sea ice extent for 2019 is 13.83 million square kilometers on February 22nd. Here’s Arctic sea ice area for good measure:
The current maximum area for 2019 is 13.10 million square kilometers, also on February 22nd. Here too is the NSIDC’s 5 day averaged extent:
This reveals a current maximum extent for 2019 of 14.705 million square kilometers on February 24th.
At this juncture you may well be wondering what the cause of that sudden sharp peak might be? Here’s your starter for ten:
Whilst overall Arctic sea ice area is unremarkable for the current decade, sea ice area in the Bering Sea is remarkable low for the time of year! What’s more much like last year the Chukchi Sea is not currently full to overflowing with sea ice, and is also lowest for the date in the AMSR2 satellite records:
I’ve also been experimenting with the new gridded CryoSat-2/SMOS thickness data from the Finnish Meteorological Institute, which reveals this:
That’s a weekly overview dated February 24th, but it does perhaps explain how such a large area of sea ice could melt so swiftly?
As luck would have it the skies are reasonably clear over the Bering Strait this morning (UTC). Here’s Terra’s view from on high of the current situation:
In addition, here is the underlying sea ice concentration data from the OSI-SAF:
Since Michael is also asserting that there currently exists “the greatest February Arctic sea ice extent (according to DMI) in your blog’s history”, here’s Arctic sea ice area excluding the extremely peripheral Okhotsk and St. Lawrence regions:
P.S. Wipneus’ Pi has processed the AMSR2 data now, and area shows another, more modest, decline today:
Both area and extent are still moving inexorably upwards:
The late February maximum still holds, on the high resolution numbers at least. The JAXA/VISHOP web site is down at the moment, so we’ll have to wait for an update to that particular metric, as well as a post weekend update to the NSIDC’s Charctic chart.
P.S. Jaxa is still down this afternoon, but here’s the latest from the NSIDC:
[Edit – March 13th]
Arctic wide area and extent have blasted past their respective late February maxima:
However Arctic sea ice area excluding the Okhotsk and St. Lawrence peripheral regions has still not exceeded the maximum formed on January 25th:
[Edit – March 14th]
This morning’s data reveal the first decline in extent for several days:
The (extremely!) tentative new maximum Arctic sea ice extent for 2019 is 13.89 million square kilometers on March 12th.
[Edit – March 15th]
JAXA is back!
UH AMSR2 confirms that extent is still declining:
[Edit – March 16th]
Arctic sea ice extent continues to decline, whilst area is still flatlining:
Meanwhile a look at freezing degree days based on the DMI’s dubiously weighted data for north of 80 degrees reveals the story of the freezing season. A historically warm start, but now back in amongst the pack of the 2010s:
[Edit – March 17th]
It looks as though there’ll be no going back from this. Arctic sea ice area is finally following extent’s decline in no uncertain terms:
Barring exceedingly unforeseen circumstances after this year’s “double top” that leaves the 2019 Arctic sea ice maximum extent numbers as follows:
UH/Wipneus AMSR2 – 13.89 million square kilometers on March 12th
JAXA/VISHOP AMSR2 – 14.27 million square kilometers on March 12th
NSIDC 5 day SSMIS – 14.78 million square kilometers on March 13th
[Edit – March 19th]
Arctic sea ice area has fallen off the proverbial cliff over the last few days. There can now be no doubt that the 2019 maximum extent has been reached:
That being the case, all other Arctic sea ice discussion for the month of March can now take place over at:
On March 13, 2019, Arctic sea ice likely reached its maximum extent for the year, at 14.78 million square kilometers (5.71 million square miles), the seventh lowest in the 40-year satellite record, tying with 2007. This year’s maximum extent is 860,000 square kilometers (332,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles) and 370,000 square kilometers (143,000 square miles) above the lowest maximum of 14.41 million square kilometers (5.56 million square miles) set on March 7, 2017. Prior to 2019, the four lowest maximum extents occurred from 2015 to 2018.
The date of the maximum this year, March 13, was very close to the 1981 to 2010 median date of March 12.
Please note this is a preliminary announcement of the sea ice maximum. At the beginning of April, NSIDC scientists will release a full analysis of winter conditions in the Arctic, along with monthly data for March.
We generally write our periodic reports on the state of Arctic sea ice around the time the PIOMAS volume numbers are published. It seems as though we’ll have a long wait for that to happen at the moment though. According to The Economist today:
America’s government shutdown has become the longest in history. Hundreds of thousands of federal workers remain either stuck at home or forced to work without pay. To reopen the government President Donald Trump is demanding $5.7bn for his border wall. Nancy Pelosi, who presides over the most polarised House of Representatives in recent memory, does not want to give it to him.
Due to the US Government Shutdown, PIOMAS ice volume and thickness data which depend on federal government generated reanalysis products, are currently not updated.
Instead of PIOMAS, let’s start instead with the January 2019 edition of the National Snow and Ice Data Center’s Arctic Sea Ice News:
As 2018 came to a close, Arctic sea ice extent was tracking at its third lowest level in the satellite record, while sea ice in the Antarctic remained at historic lows. Slightly faster growth in the first few days of the new year, mostly in the Pacific sea ice areas, has the daily sea ice extent at fifth lowest as of this post.
Now let’s take a look at our favourite high resolution AMSR2 area and extent metrics:
You can see that towards the end of December Arctic sea ice extent was verging on lowest for the date, since when it has risen quickly to reach highest for the date in the brief AMSR2 records a few days ago.
The NSIDC also mention the US Government shutdown:
Unfortunately, as a result of the partial government shutdown, we are unable to access the National Oceanic and Atmospheric Administration (NOAA) pages to retrieve information on atmospheric air temperatures and sea level pressure patterns. Instead, we turn to daily (2 meters above the surface) mean air temperatures north of 80 degrees North from the European Centre for Medium-Range Weather Forecasts (ECMWF) operational model. This analysis shows that air temperatures remained above the 1958 to 2002 average for all of December.
That brings us on to our Arctic freezing degree days graph, based on DMI data:
After a very slow start to the freezing season the FDD numbers are now vying for second place with last year, behind the astonishingly warm winter of 2016/17. In the absence of the PIOMAS volume numbers we can at least take a look at sea ice thickness. Here’s CryoSat-2:
All those sources seem to be agreed that large areas of both the Barents and Kara Seas are currently covered by young thin ice. Finally, for the moment at least, let’s take a look at some extracts from the NSIDC’s review of 2018:
January 2018 began the year with record low sea ice extents for the Arctic as a whole.
The seasonal maximum, reached on March 17, 2018, was the second lowest in the satellite record. While low extent persisted through April and May, sea ice loss during early summer was unremarkable despite above average 925 hPa air temperatures over the Arctic Ocean and Eurasia.
Air temperatures over the Arctic Ocean in July were below average, followed by above average temperatures in August. In fact, on average, August temperatures were higher than July temperatures in 2018. This is highly unusual in the Arctic and something not seen in at least 40 years.
The September 2018 seasonal minimum extent ended up slightly above the long-term linear trend line, tying with 2008 for the sixth lowest in the satellite record. After the minimum, the ocean was slow to freeze up, and October sea ice extent ended up as the third lowest. However, ice growth was very rapid in November, such that November 2018 extent approached the interquartile range of the 1981 to 2010 median. Nevertheless, large amounts of open water remained in the Barents and Chukchi Seas. By the end of December, ice conditions in the Chukchi Sea were back to average, while extent remained unusually low in the Barents Sea.
Coverage of old ice (greater than 4 years old) over the Arctic continued to decline. Such old ice covers only 5 percent of the area it used to in 1980s.
[Edit – January 13th]
Arctic sea ice area and extent have both been falling over the last few days, possibly as a result of the recent cyclone which created strong northerly winds in the Fram Strait. This is from Earth at 09:00 UTC on January 10th, showing a MSLP of 946 hPa:
Here’s what used to be referred to as JAXA extent:
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