The latest Alfred Wegener Institute sea ice concentration map shows that the Pacific side of the Central Arctic Basin is now almost completely refrozen:
On the Atlantic side of the Arctic the Kara Sea is rapidly refreezing:
However, sea ice extent in the Barents Sea and Baffin Bay is currently lowest for the date in the AMSR2 record:
Pan Arctic JAXA/ViSHOP extent is currently lowest for the date in the satellite era:
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:
JAXA/ViSHOP extent is now lowest for the date in their record going back to 1978:
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.
I was hoping that the September PIOMAS gridded thickness data would have been published by now, but no such luck. Reverting to JAXA/ViSHOP extent, after flatlining for most of September the refreeze has started in earnest over the last two weeks. Extent is currently 12th lowest in the satellite era:
The latest sea ice concentration map from Lars Kaleschke of the Alfred Wegener Institute, based on AMSR2 data, reveals plenty of new ice in the Beaufort Sea, plus a bit more to the north of the Laptev Sea:
The latest sea ice “stage of development” charts from the Canadian Ice Service confirm that, and reveal more new ice that has yet to show up in the AMSR2 data:
In the continuing absence of PIOMAS gridded thickness data (see below), here’s the latest SMOS/SMAP “thin ice thickness” map:
It appears to be badly affected by radio frequency interference on the Atlantic side of the Arctic. Here’s the raw SMOS map:
Further to a previous conversation on the subject, here’s the final NSIDC annual average extent graph for September:
As anticipated, 2025 annual average extent has proved to be the lowest in the satellite era.
[Update – October 16th]I was hoping that the September edition of the NSIDC’s “Sea Ice Today” analysis would have been published by now, but no such luck. Here’s the latest data announcement from the NSIDC:
Effective October 15, 2025, due to non-renewed funding, NSIDC has suspended or reduced several Sea Ice Today tools and services.
Discontinued:
- New monthly and mid-month analysis posts
- Sea ice analysis tool
- Sea Ice Volume
- Sea ice extent spatial comparison tool
Persisting:
- Daily Arctic and Antarctic sea ice images
- ChArctic Interactive Sea Ice Graph
- Links to Sea ice analysis data spreadsheets from the NOAA Sea Ice Index
- Reduced user support
- Sea ice annual maximum and minimum announcements (typically occurring in March and September)
Previously-published Sea Ice Today analysis posts will remain online. The discontinued Sea Ice Today products will no longer update or be maintained, and will be removed in the next several weeks.
In Sea Ice Today’s absence, here’s the MSLP and 925 hPa temperature maps for September, usually contained in the monthly analysis articles:
Plus a hastily constructed graph of the monthly average extent for September:
The Alfred Wegener Institute has published the first CryoSat-2/Sentinel 3/SMOS merged Arctic sea ice thickness data of Autumn 2025:
The Arctic sea ice volume derived therefrom is 5.43 thousand km³. The data is accompanied by the following “Product Degradation Warning”:
[Update – October 27th]SMOS input data continues to be affected by persistent and frequent radio-frequency interference (RFI) in the Barents, Kara, and Laptev Seas, resulting in missing thin ice thickness measurements. Consequently, sea ice thickness estimates for this region in the product will rely exclusively on radar altimeter data, which may lead to higher reported values than would have been obtained using SMOS.
The PIOMAS gridded thickness data for September 2025 has been belatedly released:
The associated volume graph reveals that the 2025 minimum modelled Arctic sea ice volume was 3.87 thousand km³ on September 12th, which is the 2nd lowest minimum in the PIOMAS record going back to 1979:
Whilst we’re on the topic of sea ice volume, here’s the latest “measured” volume graph:
Note the proviso about recent SMOS data above, and also that the version 3.00 data from AWI is currently only available beginning in Autumn 2023. Prior years shown on the graph above are based on version 2.06 data, which amongst other things does not incorporate Sentinel 3 data.
[Update – October 29th]Much of the Siberian side of the Arctic Ocean has now refrozen:
There is a significant difference between progress of the refreeze on the the Pacific and Atlantic sides of the Arctic. Extent in the Chukchi Sea is currently highest for the date in the AMSR2 record:
However, refreeze of the Kara Sea has yet to begin, and extent is currently lowest for the date in the AMSR2 record:
Pan Arctic JAXA/ViSHOP extent is now 6th lowest in the satellite era:
The conversation continues over on the November open thread.
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:
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 2025At the beginning of July JAXA/ViSHOP Arctic sea ice extent is still “lowest for the date” in their record going back to 1979:
The PIOMAS sea ice thickness map for June 30th reveals that the previously thick ice in the Chukchi Sea has been noticeably thinning:
The associated volume graph shows that the 2025 curve has entered the pack of other recent years. and is now 4th lowest for the date:
Continue reading Facts About the Arctic in July 2025I’ve been away on a “road trip” during the first part of June, so this month’s initial update is a trifle tardy.
After a 100k “break” yesterday JAXA/ViSHOP extent is currently in a tie with 2024 for 4th lowest for the date, and still slightly below 2012.
The PIOMAS sea ice thickness map for May 31st continues to show plenty of thick ice in the Beaufort and Chukchi Seas:
However, the associated volume graph shows the 2025 curve only slightly above the previous low for the date in 2017:
I have recently received a disturbing email from the NSIDC, which reads as follows:
Continue reading Facts About the Arctic in June 2025World renowned climate scientist Roger Pielke Jr. has just published an interesting paper in the highly respected academic journal the New York Post. It is entitled:
“Surprise! Ice is rebounding at BOTH poles — climate is more complex than we know“
According to Roger’s op-ed:
When it comes to climate change, to invoke one of Al Gore’s favorite sayings, the biggest challenge is not what we don’t know, but what we know for sure but just isn’t so.
Two new studies show that the Earth’s climate is far more complex than often acknowledged, reminding us of the importance of pragmatic energy and climate policies.
One of them, led by researchers at China’s Tongji University, finds that after years of ice sheet decline, Antarctica has seen a “surprising shift”: a record-breaking accumulation of ice…
Roger then heads for the far north, where he assures his learned readers that:
A second new paper, a preprint now going through peer review, finds a similar change at the opposite end of the planet.
“The loss of Arctic sea ice cover has undergone a pronounced slowdown over the past two decades, across all months of the year,” the paper’s US and UK authors write.
They suggest that the “pause” in Arctic sea ice decline could persist for several more decades.
Together, the two studies remind us that the global climate system remains unpredictable, defying simplistic expectations that change moves only in one direction.
I feel compelled to point out to Roger that apart from the fact that they both include the word “ice”, Arctic sea ice and the Antarctic ice sheet are approximately as similar as chalk and cheese.
Roger neglects to provide NY Post readers with a reference or helpful link to the preprint he is referring to. However luckily for my own reader(s) I have already done so. Hence I am able to quote the authors’ own words, which read as follows:
According to these climate model simulations, this pause in the loss of Arctic sea ice could plausibly continue for the next 5-10 years.
I have already emailed the authors of the preprint asking them to justify their use of the term “pause”. I’ll let you know what they have to say on the matter in due course. In the meantime I suggest that Dr. Pielke consults an English dictionary. In pseudo code:"pause" != "rebound"
I also suggest that he directs Post readers to more recent activity of yours truly’s virtual pen:
This year’s maximum extent is 1.31 million square kilometers below the 1981 to 2010 average maximum of 15.64 million square kilometers and 80,000 square kilometers below the previous lowest maximum that occurred on March 7, 2017:
Perhaps he also wouldn’t mind asking the Post’s online editor(s) to reveal this explanatory video to their viewers?
Q.E.D?
JAXA/ViSHOP extent is no longer “lowest for the date”! After “flatlining” for most of April the metric is now in the midst of a close knit group of the other years in the 2020s:
The high pressure area over the Central Arctic persisted through the second half of April, and so did the consequent drift of ice from the Pacific side of the Arctic to the Atlantic periphery:
AWI’s sea ice area for the Greenland Sea is currently “highest for the date” in the AMSR2 record that started in July 2012:
The offshore winds along the Laptev Sea coast have continued, and sea ice area is now “lowest for the date”:
The first signs of a break in the high pressure dominance are appearing. GFS currently forecasts that a low pressure area will enter the Central Arctic, bring above zero temperatures over the Kara Sea on Sunday:
Continue reading Facts About the Arctic in May 2025JAXA/ViSHOP extent finished the month of March “lowest for the date” once again:
However, since then the graph has been “flatlining” and extent is now above 2019 and rapidly approaching the rest of the recent pack.
At the end of March PIOMAS Arctic sea ice volume had increased to 21.21 thousand km³, still 2nd lowest for the date in the PIOMAS record:
Here is the corresponding PIOMAS sea ice thickness map for March 31st 2025:
For comparison purposes, here is the “near real time” CryoSat-2/SMOS merged thickness data from the Alfred Wegener Institute:
Continue reading Facts About the Arctic in April 2025