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:
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.
Thanks to Going South for the heads up:
By way of additional background information, Wikipedia asserts that:
Grok is a generative artificial intelligence chatbot developed by xAI. It was launched in November 2023 by Elon Musk as an initiative based on the large language model (LLM) of the same name. Grok has apps for iOS and Android and is integrated with the social media platform X (formerly known as Twitter), Tesla vehicles, and Tesla’s Optimus robot. The chatbot is named after the verb grok, coined by American author Robert A. Heinlein in his 1961 science fiction novel Stranger in a Strange Land to describe a deeper than human form of understanding.
The bot has generated various controversial responses, including conspiracy theories, antisemitism, and praise of Adolf Hitler, as well as referring to Musk’s views when asked about controversial topics or difficult decisions. Updates since 2023 have shifted the bot politically rightward to provide conservative responses to user queries.
and that:
Michael D. Shellenberger is an American author and journalist. He is the first endowed professor at the University of Austin, serving as CBR Chair of Politics, Censorship, and Free Speech.
Shellenberger is a prominent heterodox thinker on topics including climate change and homelessness…
University of Austin is not a school recognized by the U.S. National Center for Education Statistics.
In other news, is Grok schizophrenic?
[Update – November 3rd]Grok seem to having a lot of trouble answering this simple question:
Do you have a link to the image(s) in the U.S. Naval Institute Photo Archive you are referring to?
— Snow White (@GreatWhiteCon) November 3, 2025
I ask because I can't find them!
He/she/it/they has been pondering the problem for over an hour now.
[Update – 15:00 UTC November 3rd]I got bored waiting for Grok to get back to me, so I asked ChatGPT much the same question. I was informed:
Suggested links
The Naval History & Heritage Command (NHHC) entry: “Skate II (SSN-578)” on history.navy.mil — gives the official history and mentions the March 17, 1959 surfacing. history.navy.mil
An archived photograph in the NHHC image collection: “USN 1040961 USS SKATE (SSN–578)” which shows the submarine moored to the ice pack. flickr.com
A blog article “USS Skate at the North Pole – Truth and Fantasy Fiction” that collects several of the historic photographs and discusses their context. greatwhitecon.info
I asked ChatGPT to check out the final link in more detail. I was informed:
What GreatWhiteCon does well:
It collects and reproduces the historic images and contemporary captions, and discusses how those images have been interpreted (or misinterpreted) over time. That makes it a handy one-stop place to see the pictures and some commentary.What GreatWhiteCon is not:
It is a blog/analysis piece (2018) rather than an official or archival source. That means its interpretation is useful, but any factual claim that matters (dates, official captions, archival catalog numbers) is best checked against the primary records (Naval History & Heritage Command, National Archives, contemporary magazines, USNI Proceedings).
Grok has a rather different interpretation of what Great White Con does well. Allegedly “Snow White”:
Counters alarmist views… promoting nuanced data interpretation over binary claims.
Today my discussion with Grok on XTwitter turned (amongst other things) to the recent United States Department of Energy “Critical Review of Impacts of Greenhouse Gas Emissions on the U.S. Climate” report.
My conversation with Grok is remarkably reminiscent of mud wrestling with “skeptical” Twitter trolls:
Watch this space!
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 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 2025I frequently post a summary of the Arctic section of the United States’ National Snow and Ice Data Center’s monthly review of the current state of the cryosphere. Here is the most recent edition.
However, this month I have some additional bad news to report. According to a May 6th “Level of Service Update for Data Products” from the NSIDC:
Effective May 5, 2025, NOAA’s National Centers for Environmental Information (NCEI) will decommission its snow and ice data products from the Coasts, Oceans, and Geophysics Science Division (COGS).
As a result, the level of services for affected products below will be reduced to Basic—meaning they will remain accessible but may not be actively maintained, updated, or fully supported.
- Sea Ice Index
- Snow Data Assimilation System (SNODAS) Data Products
- Glacier Photograph Collection
- U.S. National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format
- Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward
- World Glacier Inventory
If you rely on these products in your work, research, education, or planning, we invite you to share your story at [email protected]. Your input can help us demonstrate the importance of these data sets and advocate for future support.
I will certainly share my story with the NSIDC. If you are a resident of the US you may also wish to contact your local friendly neighbourhood politician(s) about the matter?
[Update – May 9th]Mark Serreze, Director of the National Snow and Ice Data Center, replied to my email and told me that:
We are acutely aware of the importance of the SII and Sea Ice Today. Millions of visits per year. High priority. We’re in the middle of discussions about to make sure that we have continuity.
Thanks for your support. Everything helps.
One of the less well known data products provided by the NSIDC is EASE-Grid Sea Ice Age.
I recently used that particular mine of essential cryospheric information to produce this educational YouTube video:
The video reveals the underlying reason for the “fast transition” of Arctic sea ice cover from thick multi-year ice to a reduced area of much more mobile young ice.
To be continued…
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 2025The time has arrived to start taking a close look at the assorted different Arctic sea ice extent metrics, in order to ascertain their respective maxima for 2025. To begin with here’s Zack Labe’s overview of previous years’ maxima:
It now seems highly likely that 2025’s maximum extent will ultimately prove to be the lowest in the satellite era. The remaining question is when this year’s maximum will occur.
My speculation yesterday that AWI’s flavour of Arctic sea ice extent had already achieved its maximum value for 2025 has been negated today:
The NSIDC 5 day average and JAXA extent metrics are also currently at their maximum levels for the year so far, so let’s wait and see which one is the first to take a downward turn.
[Update – March 28th]The National Snow and Ice Data Center have called the maximum extent of Arctic sea ice for 2025:
On March 22, Arctic sea ice likely reached its maximum extent for the year, at 14.33 million square kilometers, the lowest in the 47-year satellite record. 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.
Continue reading The 2025 Maximum Arctic Sea Ice Extent
Christmas is coming, and even as we speak Snow White is heading for the geographical North Pole to assist Santa’s little helpers in their annual gift delivery mission:
We’ll start the festive season with a graph of JAXA/ViSHOP extent, which is in a “statistical tie” with 2020 for 2nd lowest for the date in the satellite era:
Here’s the PIOMAS gridded thickness data for the end of November 2024:
On November 30th Arctic sea ice volume had increased to 9.99 thousand km³, 3rd lowest for the date in the PIOMAS record:
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 December 2024