Tag Archives: AMSR2

The 2020 Maximum Arctic Sea Ice Extent

Extent, , , , , , , , ,

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.

Facts About the Arctic in October 2019

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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 MOSAiC Expedition has started in earnest, with Polarstern and Akademik Fedorov in amongst the sea ice at long last:

However:

[Edit – October 3rd]

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:

and the volume graph:

Since I’m involved is a heated “debate” about Arctic sea ice trends over at ex Prof. Judy’s, here’s an added bonus this month. The September volume trend:

[Edit – October 6th]

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”.

Plus a stunning image from Mike Horn and Borge Ousland as they attempt to “walk” to the North Pole then on towards Svalbard:

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:

Here’s the evidence:

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:

See:

“Warming of the interior Arctic Ocean linked to sea ice losses at the basin margins” Mary-Louise Timmermans, John Toole, Richard Krishfield (2018)

“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.”

Watch this space!

Facts About the Arctic in June 2019

Volume, , , , , , , , , ,

In my humble opinion summer in the Arctic summer starts on June 1st, so let’s check the current sea ice situation in the once frozen North. For details of the preconditioning of the ice during the Arctic spring see “Melt Pond May“, where I concluded that:

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.

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. Other than that Arctic sea ice in 2019 looks to be in worse shape than in 2012.

And how have things progressed over the last few days? Take a look at this:

Our “Arctic Basin” metric encompasses the Central Arctic plus the Beaufort, Chukchi, East Siberian and Laptev Seas. It is currently headed into uncharted waters. The effect on overall Arctic sea ice extent is also readily visible:

This year both the CPOM version of CryoSat-2 thickness and the University of Bremen’s SMOS thickness maps are continuing to be published during the melting season:

Take them with a large pinch of salt at this time of year!

Finally, for the moment at least, liquid water is starting to seep out of the Lena Delta:

NASA Worldview “false-color” image of the Lena Delta on June 3rd 2019, derived from the MODIS sensor on the Aqua satellite
NASA Worldview “false-color” image of the Lena Delta on June 3rd 2019, derived from the MODIS sensor on the Aqua satellite

For comparison purposes please also take a look at the same date in 2016:

NASA Worldview “false-color” image of the Lena Delta on June 3rd 2016, derived from the MODIS sensor on the Aqua satellite
NASA Worldview “false-color” image of the Lena Delta on June 3rd 2016, derived from the MODIS sensor on the Aqua satellite

and the previous date in 2012:

NASA Worldview “false-color” image of the Lena Delta on June 2nd 2012, derived from the MODIS sensor on the Aqua satellite
NASA Worldview “false-color” image of the Lena Delta on June 2nd 2012, derived from the MODIS sensor on the Aqua satellite

[Edit – June 4th]

A significant area of the Laptev Sea ice is now turning a much darker shade of blue using the band 7-2-1 false colour combination:

NASA Worldview “false-color” image of the Laptev Sea on June 4th 2019, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the Laptev Sea on June 4th 2019, derived from the MODIS sensor on the Terra satellite

In addition the DMI >80N temperature metric has reached the zero Celsius line well ahead of schedule:

[Edit – June 5th]

The May PIOMAS numbers have been released! Here is the Wipneus generated state of play on May 31st:

and here is the all too familar multi-year graph:

[Edit – June 10th]

As reported in this year’s Northwest Passage article:

Any early bird traversing the Northwest Passage from west to east could now sail through open water around Point Barrow, along the Alaskan and Canadian coast and into the Amundsen Gulf:

Arctic Basin sea ice extent is still descending through uncharted territory:

and Basin area currently looks poised to follow suit:

[Edit – June 11th]

There’s a beautifully clear view of the Siberian coast today, with vast areas of melt ponds visible on VIIRS false colour:

NASA Worldview “false-color” image of the Laptev & East Siberian Seas on June 11th 2019, derived from the VIIRS sensor on the Suomi satellite
NASA Worldview “false-color” image of the Laptev & East Siberian Seas on June 11th 2019, derived from the VIIRS sensor on the Suomi satellite

The Arctic Basin area has indeed taken a nosedive into uncharted territory:

By way of comparison sea ice area on the Atlantic periphery is in amongst the recent pack, thanks to the almost continual drift in that direction over last winter:

[Edit – June 13th]

High resolution AMSR2 extent has been in a “statistical tie” with 2016 for a few days:

However the NSIDC’s 5 day average extent has reached a clear new low for the date, in the satellite record at least:

[Edit – June 14th]

Especially for AJBT, here’s the Slater Probabilistic Ice Extent prediction for August 3rd:

and here’s the current DMI >80N temperature graph:

Finally, for the moment at least, there is not very much fast ice left at Utqiaġvik:

[Edit – June 15th]

The sea ice in the Laptev Sea is starting to break up:

NASA Worldview “false-color” image of the Laptev Sea on June 15th 2019, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the Laptev Sea on June 15th 2019, derived from the MODIS sensor on the Terra satellite

As is the fast ice in the Beaufort Sea:

NASA Worldview “false-color” image of the Beaufort Sea on June 14th 2019, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the Beaufort Sea on June 14th 2019, derived from the MODIS sensor on the Terra satellite

Meanwhile the MSLP of the cyclone currently spinning over Severnaya Zemlya was down to 976 hPa at 06:00 UTC this morning:

NASA Worldview “false-color” image of the Kara Sea on June 15th 2019, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the Kara Sea on June 15th 2019, derived from the MODIS sensor on the Terra satellite

An early morning image from the Utqiaġvik webcam:

Especially for Mateo (see below) here’s the current high resolution Arctic Basin sea ice area:

and extent:

Note that the recent cyclones have caused a temporary jump in sea ice extent, but not in area.

[Edit – June 17th]

The Lincoln Sea has turned noticeably bluer on MODIS bands 7-2-1 false colour:

NASA Worldview “false-color” image of the Lincoln Sea on June 17th 2019, derived from the MODIS sensor on the Aqua satellite
NASA Worldview “false-color” image of the Lincoln Sea on June 17th 2019, derived from the MODIS sensor on the Aqua satellite

[Edit – June 19th]

The sea ice off the Lena Delta has started to collapse:

NASA Worldview “false-color” image of the Laptev Sea on June 19th 2019, derived from the MODIS sensor on the Aqua satellite
NASA Worldview “false-color” image of the Laptev Sea on June 19th 2019, derived from the MODIS sensor on the Aqua satellite

Meanwhile the clear water off Point Barrow is opening up further:

Finally, for the moment at least, here is the current view from the Utqiaġvik (Barrow as was) sea ice webcam:

P.S. The mid month PIOMAS numbers have been released, and Wipneus has worked his usual magic:

2019 sea ice volume is currently in a “statistical tie” with 2012, in 2nd place behind 2017:

[Edit – June 22nd]

The fast ice in the Vilkitsky Strait has started to break up:

NASA Worldview “false-color” image of the Vilkitsky Strait on June 22nd 2019, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the Vilkitsky Strait on June 22nd 2019, derived from the MODIS sensor on the Terra satellite

Sea Ice area along the Northern Sea Route is currently the lowest for the date in the AMSR2 ere:

In addition the June 2019 Sea Ice Prediction Network report has been released. Here’s the summary:

Again, as in previous years, the spread in the dynamical models are larger compared with statistical models. Overall, the heuristic method has the lowest projected September sea-ice extent value with a median at 4.09 million square kilometers, and the dynamical models have the highest number with the median at 4.56 million square kilometers.

[Edit – June 23rd]

Arctic wide sea ice area is now lowest for the date in the high resolution AMSR2 record, although extent has yet to follow suit:

If you exclude the peripheral seas, which are all largely ice free by mid September in this day and age, the picture is extremely stark:

A brief glimpse through the clouds reveals that the North Pole is now starting to feel the recent heat:

NASA Worldview “false-color” image of the North Pole on June 22nd 2019, derived from the MODIS sensor on the Terra satellite
NASA Worldview “false-color” image of the North Pole on June 22nd 2019, derived from the MODIS sensor on the Terra satellite

[Edit – June 27th]

Arctic wide sea ice extent is now lowest for the date in the high resolution AMSR2 record:

Here’s Arctic wide sea ice area, which is still well below the rest of the pack:

[Edit – June 29th]

As the end of the month draws near let’s take a look at sea ice area along a couple of the famous sea routes above the Arctic Circle. First of all here’s the Northern Sea Route, comprising the Kara, Laptev, East Siberian and Chukchi Seas:

Next here’s the Northwest Passage, comprising the Chukchi and Beaufort Seas plus the channels of the Canadian Arctic Archipelago and Baffin Bay:

For completeness here too are the current Arctic wide area and extent numbers:

Watch this space!

Facts About the Arctic in April 2019

Volume, , , , , , , , , ,

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:

Accompanied by his sage thoughts on the matter:

That has to be your lamest cherry-pick on record.

Here too is the latest graph of Rah and Tony’s beloved DMI “Arctic air temps”:

P.S. Here are the April 1st numbers from Steve/Tony’s current metric du jour:

and from the National Snow and Ice Data Center:

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.

Facts About the Arctic in March 2019

Volume, , , , , , , , , , ,

Wipneus has recently updated the mid month PIOMAS gridded thickness map, which looks like this:

The accompanying PIOMAS volume graph currently shows 2019 in seventh place:

We now have a new thickness metric to peruse each month. Here’s the gridded merged CryoSat-2/SMOS thickness data from the Finnish Meteorological Institute:

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:

The 2019 Maximum Arctic Sea Ice Extent

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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:

charctic-20170221

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:

Terra's view of the Bering Strait on March 1st 2019
Terra’s view of the Bering Strait on March 1st 2019

 
[Edit – March 1st PM]

The “low resolution” version of JAXA extent has fallen once again today:

Do you suppose that the current maximum of 14.19 million square kilometers on February 22nd will hold until All Fools’ Day and beyond?

 
[Edit – March 2nd]

An animation of recent movements of sea ice in the Bering and Chukchi Seas:


 

Note the recent spread of open water across the southern Chukchi Sea.

 
[Edit – March 3rd]

Another angle on the Chukchi Sea, plus significant areas of open water now becoming evident in the Beaufort Sea:

 

[Edit – March 5th]

Some alternative views on Arctic sea ice thickness:

PIOMAS via Wipneus:

Blended CryoSat-2/SMOS:

plus close ups of the Bering/Chukchi area:

and the Atlantic periphery:

Please note the change of scale.

 

[Edit – March 6th]

Arctic sea ice extent is currently rebounding:

although not in all the peripheral seas:

 

[Edit – March 7th]

High resolution AMSR2 area and extent both declined today:

Long distance swells are already reaching the Bering Sea, with much more to come:

 

[Edit – March 9th]

Wipneus’ trusty Raspberry Pi hasn’t crunched the high res AMSR2 numbers yet, so let’s take a look at some other extent metrics.

Here’s JAXA’s “low res” AMSR2 numbers:

Here too is the NSIDC’s 5 day average:

By special request from Michael Ohere for the first time is the DMI’s take on Arctic sea ice extent:

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:

In addition, here is the underlying sea ice concentration data from the University of Hamburg:

 

[Edit – March 10th]

Both area and extent increased today:

including increases on both the Atlantic:

and Pacific sides of the Arctic:

 

[Edit – March 11th]

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:

Facts About the Arctic in March 2019

 

[Edit – March 21st]

The NSIDC have provisionally confirmed this year’s maximum extent:

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.

Facts About the Arctic in January 2019

Thickness, , , , , , , , , , , , , ,

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.

and according to the Polar Science Center at the University of Washington:

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.

Graph by Zack Labe
Graph by Zack Labe

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:

followed by SMOS:

and since a change is as good as a rest here’s the latest map from the Russian Arctic and Antarctic Research Institute for good measure:

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:

Meanwhile up in the stratosphere at 10 hPa the polar vortex has gone into reverse:

Or to be more precise:

The 2018 Arctic Sea Ice Metric Minima

Extent, , , , , , , , , ,

September is upon us once again, the month in which the assorted Arctic sea ice area and extent metrics (almost) always reach their respective annual minima. Now we are free to start speculating about what the assorted minima will be, and on what date.

To begin with let’s take a look at our much beloved high resolution AMSR2 metrics derived by “Wipneus” from the University of Hamburg’s AMSR2 concentration data:

Arctic-Area-2018-09-01

Arctic-Extent-2018-09-01

There’s currently some divergence between the area and extent graphs. Area is declining rapidly for the time of year, whilst extent seems to almost have come to a standstill!

Next here’s the prediction of the late, great Andrew Slater’s Probabilistic Ice Extent algorithm:

SPIE-extent-20180901

Before looking at some of the other metrics we’ll wait for the effect of the assorted storms currently circling the Arctic to play out. Here’s how the AMSR2 concentration map looks at the moment:

Arc_20180901_res3.125

whilst here’s the University of Bremen’s summer SMOS sea ice “thinness” map:

SMOS-20180901

 

[Edit – September 3rd]

UH AMSR2 area and extent both increased yesterday, so we have a (very!) provisional minimum extent of 4.35 million square kilometres on September 1st.

 

[Edit – September 4th]

Area and extent have both increased again:

Arctic-Area-2018-09-03

Arctic-Extent-2018-09-03

Is the minimum already in, or will the storms still circulating around the Arctic Ocean reverse that trend over the next few days?

 

[Edit – September 6th]

High resolution area and extent both posted marginal new lows for the year yesterday:

Arctic-Area-2018-09-05

Arctic-Extent-2018-09-05

 

[Edit – September 29th]

According to the latest edition of the NSIDC’s Arctic Sea Ice News:

On September 19 and 23, Arctic sea ice appeared to have reached its seasonal minimum extent for the year, at 4.59 million square kilometers (1.77 million square miles). This ties 2018 with 2008 and 2010 for the sixth lowest minimum extent in the nearly 40-year satellite record.

Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

Figure2_09232018

The NSIDC numbers are based on a 5 day average, whereas the one day high resolution AMSR2 extent reached a minimum of 4.195 million square kilometers on September 17th:

Arctic-Extent-2018-09-28

The AMSR2 area minimum occurred significantly earlier. 3.737 million square kilometers on September 9th:

Arctic-Area-2018-09-28

The 2018 Maximum Arctic Sea Ice Extent

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According to the latest edition of the National Snow and Ice Data Center’s “Arctic Sea Ice News”

On March 17, 2018, Arctic sea ice likely reached its maximum extent for the year, at 14.48 million square kilometers (5.59 million square miles), the second lowest in the 39-year satellite record, falling just behind 2017. This year’s maximum extent is 1.16 million square kilometers (448,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles).

The four lowest seasonal maxima have all occurred during the last four years. The 2018 maximum is 60,000 square kilometers (23,200 square miles) above the record low maximum that occurred on March 7, 2017.

Here’s a close up view of recent maxima via the NSIDC’s Charctic interactive sea ice graph:

Charctic-20180323

Next let’s take a look at extent data from the Japanese National Institute of Polar Research, colloquially referred to as “JAXA extent”

VISHOP_Extent-20180323

In this case the maximum was 13.89 million square kilometers, also on March 17th.

Here too are the extent and area graphs based on Wipneus’ processing of the University of Hamburg’s AMSR2 based concentration data:

UH-Arctic-Extent-2018-03-23

UH-Arctic-Area-2018-03-23

They highlight the surge in Arctic sea ice area in the middle of March due to the sudden “cold snap”:

meanT_2018-03-24
Looking at the third Arctic dimension, here’s the latest SMOS thickness map from the University of Bremen:

SMOS-20180323

and here’s the latest CryoSat-2 thickness map:

CS2-thk_28-2018-03-21

They reveal large areas of relatively thin sea ice in the Okhotsk and Barents Seas where the ice can now be expected to melt as quickly as it formed. There is also remarkably little sea ice in the Bering Sea for the time of year:

UH-Bering-Extent-2018-03-23

The February 2018 Fram Strait Cyclones

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As already mentioned in our February Arctic overview, another storm is brewing. Here is this morning’s weather forecast for Longyearbyen, the capital of Svalbard:

svalbard_forecast_20180204

Much like last month, temperatures are above zero and rain is forecast. That’s because once again the current synoptic chart from Environment Canada shows a warm wet flow from way down south over Svalbard and on into the Central Arctic:

Synopsis-20180204-06Z-Crop

Next here’s the current combined wave and swell height forecast for the Svalbard area:

Significant_height_of_combined_w in multi_1.glo_15mext.20180204_00037

and here’s the associated wave period forecast:

Mean_period_of_wind_waves_surfac in multi_1.glo_15mext.20180204_00037

It’s still showing 10 meter waves with a 15 second period north of Svalbard tomorrow lunchtime. Somewhat unusually for the Arctic these aren’t merely giant wind waves. Zooming in on the Fram Strait and breaking out the underlying primary swell reveals:

Significant_height_of_swell_wave in multi_1.glo_15mext.20180204_00041

Mean_period_of_swell_waves_order in multi_1.glo_15mext.20180204_00041

A long distance swell of that magnitude is going to cause some damage.

 

[Edit – February 5th]

The current ECMWF forecast for a split polar vortex, courtesy of Ice Shieldz on the Arctic Sea Ice Forum:

Polar View Wind Speed 10 hPa 20180204

This is suggestive of more cyclones to come, but sticking with the current one for now, here is the MSLP chart at 00:00 UTC this morning showing the cyclone’s central pressure has dropped to 952 hPa:

Synopsis-20180205-00Z-Crop

Here too is the current WaveWatch III forecast for 15:00 UTC today:

Significant_height_of_combined_w in multi_1.glo_15mext.20180205_00016

Mean_period_of_wind_waves_surfac in multi_1.glo_15mext.20180205_00016

The peak of the swell north of Svalbard is now slightly later than originally forecast, but it’s still enormous!

Here’s a single Sentinel 1B synthetic aperture radar image that captures the position of the ice edge north of Svalbard yesterday quite nicely:

S1B_Svalbard_20180204T0654

 

[Edit – February 7th]

A brief overview of the effect of the recent cyclone on the sea ice in the Arctic via AMSR2:

UH-Arctic-Area-2018-02-06

UH-Arctic-Extent-2018-02-06

atlantic-201802-1280

Click the image to animate it.

 

[Edit – February 8th]

An Arctic wide take via Thomas Lavergne on Twitter:

plus the latest AMSR2 concentration map:

Arc_20180207_res3.125_LARGE

 

[Edit – February 9th]

An interesting insight into CryoSat-2 sea ice thickness measurements from Stefan Hendricks on Twitter:

Plus Judah Cohen on the split polar vortex: