Tag Archives: Thickness

Facts About the Arctic in November 2026

At the beginning of November JAXA/ViSHOP extent is in a “statistical tie” with 2012 for 6th lowest for the date in the satellite era:

In the continuing absence of the Alfred Wegener Institute’s Arctic sea ice concentration map, here once again is the AMSR3 based map from the University of Bremen:

Here too is the University of Bremen’s latest SMOS/SMAP “thin ice thickness” map:

[Update – November 10th]

The JAXA web site is online once again, but currently extent data is only available up to November 7th:

On the 7th extent was 5th lowest for the date.

After a brisk start to the freezing season, the slope of the DMI freezing degree days graph has reduced over recent days:

At long last atmospheric conditions over the Arctic in October failed to show persistent low pressure over the Central Arctic Basin. In October there was a dipole pattern, with low pressure on the Siberian side of the CAB opposed to high pressure on the Canadian side. Temperatures at the 925 hPa pressure level were anomalously high across most of the Arctic, in particular over the Barents Sea. Baffin Bay was the only area slightly cooler than average:

Much like last month, NSIDC average sea ice extent for October is significantly above the long term trend:

[Update – November 11th]

JAXA extent has caught up with the recent backlog, and GS will no doubt be overjoyed to find it currently in 4th lowest position for the date. In the satellite era!

Here too is the current Arctic sea ice thickness map, based on AWI’s combined CryoSat-2, Sentinel 3 and SMOS data:

For the 7 days centred on November 6th Arctic sea ice volume  was 8038.9 km³.

Finally for today, here is the University of Bremen’s latest AMSR3 concentration map for the Arctic Ocean:

[Update – November 15th]

The NSIDC have published their October summary, which includes an update on sea ice cover in the Northwest Passage:

Despite warm conditions for most of the summer in the Canadian Archipelago, sea ice blocked the northern (deep water) route of the Northwest Passage, from Parry Channel to Melville Sound, through the late summer. That route had above average ice extent throughout the spring and early summer. However, as has been the case for most years in this century, the southern route—pioneered by Amundsen in 1905—was nearly ice free by mid-August and remained relatively open until mid-October.

In other news, Lars Kaleschke’s “sea ice leads” map of AWI concentration data is back! The animation still contains a big gap, but here is the map for November 14th at least:

Watch this space!

The Northwest Passage in 2026

For those of you unfamiliar with the names of the assorted islands and channels of the Canadian Arctic Archipelago here is a map that hopefully helps:

Plus another map detailing the routes through the Canadian Arctic Archipelago that have previously been successfully navigated by vessels large and small:

The sea ice in Lancaster Sound and the Amundsen Gulf is breaking up, and melt ponds are now visible on the fast ice across much of the southern route through the Canadian Arctic Archipelago:

“False colour” image of the Canadian Arctic Archipelago on June 17th from the MODIS instrument on the Terra satellite

The melt ponds previously visible in the Coronation Gulf now appear to have drained:

“False colour” image of the Canadian Arctic Archipelago on June 3rd from the MODIS instrument on the Aqua satellite
Continue reading The Northwest Passage in 2026 →

Facts About the Arctic in June 2026

The JAXA/ViSHOP web site is currently undergoing maintenance, but here is how their 2 day average extent graph looked for June 2nd:

Extent was 3rd lowest in the JAXA record, behind 2016 and 2019.

The Alfred Wegener Institute’s sea ice concentration data shows that the Bering Sea is now largely free of sea ice, and the areas of open water in the Beaufort, Chukchi, East Siberian and Laptev Seas continue to expand:

The sea ice concentration map also shows open water in much of Lancaster Sound. Also apparent is the widespread presence of melt ponds along the southern part of the Canadian Arctic Archipelago. Here’s a closer, albeit somewhat cloudy, look:

“False colour” image of the Canadian Arctic Archipelago on June 3rd from the MODIS instrument on the Aqua satellite
Continue reading Facts About the Arctic in June 2026 →

Facts About the Arctic in April 2026

In early April JAXA Arctic sea ice extent is 3rd lowest for the date, albeit in a “statistical tie” with last year:

The Alfred Wegener Institute’s regional extent graphs reveal an intriguing divergence on the Pacific periphery, where sea ice extent in the Sea of Okhotsk is at an all time low for the date in the AMSR2 record:

On the other hand extent in the Bering Sea is close to an all time high:

On the Atlantic periphery extent is less extreme, although there is currently open water north of Svalbard:

Looking at the third dimension, here is the AWI’s CryoSat-2/Sentinel 3/SMOS Arctic sea ice thickness map at the end of March:

Continue reading Facts About the Arctic in April 2026 →

Facts About the Arctic in March 2026

JAXA Arctic sea ice extent has just reached a new high for the year. At 13.76 million km² extent is currently 4th lowest for the date, just below last year’s maximum of 13.78 million km²:

At the end of February PIOMAS Arctic sea ice volume was 2nd lowest for the date at 17.54 km³:

Here is the associated sea ice thickness map:

For comparison purposes, here is the Alfred Wegener Institute’s CryoSat-2/Sentinel 3/SMOS Arctic sea ice thickness map at the end of February:

and the associated volume graph:

[Update – March 22nd]

JAXA extent is currently lowest for the date in their record going back to 1979. It’s highly likely that the metric peaked on March 7th which is a new record low maximum, albeit by a mere 20 thousand km²:

By way of a contrast, the National Snow and Ice Data Center’s 5 day averaged extent maximum of 14.29 million km² was reached on March 15th:

Here is the mid month update on the AWI’s CryoSat-2/Sentinel 3/SMOS Arctic sea ice thickness map:

Here too is the associated sea ice volume graph:

Next here are the ERA5 MSLP and 925 hPa air temperature anomaly maps for February 2026, now in “Greenland down” orientation to match the thickness maps:

together with the NSIDC monthly average extent graph for February:

The conversation continues over on the April open thread.

Facts About the Arctic in February 2026

Hudson Bay has fully frozen over during January. However, there is still open water north of Svalbard and in the North Water Polynya. It’s even possible to go swimming in the Nares Strait according to the latest AMSR2 concentration map from the Alfred Wegener Institute:

JAXA extent is currently 3rd lowest for the date, in a “statistical tie” with 2017:

Looking at the third dimension next, PIOMAS volume was second lowest for the date by a whisker at the end of January:

Here’s the associated sea ice thickness map:

Continue reading Facts About the Arctic in February 2026 →

Facts About the Arctic in January 2026

A Happy New Year to our loyal reader(s) from the shores of (the now frozen) Santa’s Summer Swimming Pool:

Note that for the hardy, swimming is still possible north of Svalbard, in parts of Hudson Bay and the North Water Polynya.

At the end of 2025 JAXA extent was 2nd lowest for the date, albeit in a “statistical tie” with 2024 and 2017:

NSIDC average extent for December is lowest in the satellite era by a considerable margin:

Continue reading Facts About the Arctic in January 2026 →

Facts About the Arctic in November 2025

The latest Alfred Wegener Institute sea ice concentration map shows the East Siberian and Laptev Seas almost completely refrozen. However, refreeze of the Kara Sea has barely begun:

Across the Arctic as a whole the refreeze has slowed significantly, and JAXA/ViSHOP extent is now 2nd lowest in the satellite era:

However, average NSIDC extent for the month of October was higher than last year and above the linear trend:

The ERA5 MSLP map for October shows high pressure over Siberia, associated with lower than normal air temperatures at 925 hPa across the region. However, temperatures across almost the entire Arctic Ocean were above normal:

High Arctic freezing degree days based on DMI >80N data were lowest for the date at the beginning of November:

Here is the Alfred Wegener Institute’s CryoSat-2/Sentinel 3/SMOS Arctic sea ice thickness map at the end of October:

Here too is the associated sea ice volume graph:

Bear in mind the caveats about the current lack of reliable SMOS data on the Atlantic side of the Arctic, and that Sentinel 3 data is only incorporated from Autumn 2023.

[Update – November 20th]

Refreeze of the Beaufort Sea is complete, and refreeze of the Kara Sea has started in earnest:

However, the Barents Sea is still sea ice free and refreeze of Hudson Bay has barely begun:

JAXA extent is still second lowest for the date:

The PIOMAS gridded thickness data for October has yet to be corrected, but here is the mid month thickness map from AWI:

Here too is the associated volume graph:

[Update – November 27th]

JAXA/ViSHOP extent is now lowest for the date in their record going back to 1978:

[Update – December 5th]

The PIOMAS team have finally published gridded thickness data for October and November, so here are the October 31st and November 15th thickness maps:

The conversation continues over on the December open thread, including the latest PIOMAS data.

Facts About the Arctic in September 2025

At the beginning of last month JAXA/ViSHOP extent was third lowest for the date in the satellite era. With the date of the 2025 minimum extent rapidly approaching that is no longer the case:

Whilst JAXA extent is now 10th lowest, PIOMAS volume remains second lowest for the date:

Here’s the associated thickness map. Note the change of scale from last month

Compare and contrast that map with the AWI’s sea ice concentration map, particularly in the Beaufort Sea area:

Continue reading Facts About the Arctic in September 2025 →

Facts About the Arctic in August 2025

At the beginning of August JAXA/ViSHOP extent is in a “statistical tie” for 3rd lowest for the date in the satellite era:

Extent has been declining rapidly for the past few days, and further losses look likely in the Beaufort Sea on either side of an arm of high concentration ice visible in the Alfred Wegener Institute’s map of sea ice concenration:

The ice on the Atlantic side of the Arctic is starting to look highly fragmented, all the way to the North Pole.

Continue reading Facts About the Arctic in August 2025 →