I 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:
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:
JAXA/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:
The 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:
After spending several weeks in the unfortunate position of lowest for the date, JAXA/ViSHOP Arctic sea ice extent has just risen above 2015. By a mere 10,000 km²:
Despite the fact that JAXA extent is still rising, AWI extent has potentially already achieved its maximum value for 2025:
Somewhat belatedly, here is the PIOMAS sea ice thickness map for February 28th 2025:
At the end of February Arctic sea ice volume had increased to 19.32 thousand km³, still 2nd 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:
AWI have also released a new version of their thickness product, incorporating additional data from the two Sentinel 3 satellites. The thickness data for February 28th, looks slightly different:
This isn’t exactly “shock news”, since we (slightly hesitantly!) predicted this 5 days ago.
A GFS 2 meter temperature chart revealing greater than zero degrees Celsius at the North Pole later today:
The 2 meter temperature anomaly at the Pole is almost off the charts:
Plus the cause of these unusual numbers, a cyclone with central pressure of 959 hPa spinning north of Ellesmere Island at 18:00 UTC this evening:
All of which has led to the JAXA/Vishop Arctic sea ice extent being the lowest for the date since 1979 at least by a significant margin:
The New Year began with JAXA/ViSHOP extent lowest for the date in the satellite era, just below 2018 . Since then extent has reduced, and there is now a large gap:
The primary reason for this is the remaining open water in Hudson Bay:
In previous years Hudson Bay has been covered by sea ice by this time of year, but in 2025 a large area remains unfrozen in early January!
Due to the way PIOMAS handles the leap years the last gridded thickness data of 2024 is dated December 30th:
By December 30th Arctic sea ice volume had increased to 13.61 thousand km³, 2nd lowest for the date in the PIOMAS record:
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:
The Laptev and East Siberian Seas have now refrozen. Consequently Arctic sea ice extent is now increasing more slowly, and JAXA/ViSHOP extent is 3rd lowest for the date in the satellite era:
Introducing the third dimension, here’s the PIOMAS gridded thickness data for the end of October 2024:
Note the change in scale from previous months, to allow for easier comparison with the “near real time” CryoSat-2/SMOS merged thickness data from the Alfred Wegener Institute:
The JAXA extent graph is currently not updating, so let’s begin this month with the latest AMSR2 sea ice concentration map from the Alfred Wegener Institute. Click the image to see a ~10 Mb animation of the last four weeks:
Note in particular the restart of export into the East Greenland Sea via the Fram Strait:
and the movement of ice within the Canadian Arctic Archipelago:
The PIOMAS gridded thickness data for September 2024 has been released:
