There’s lots of coverage specifically about assorted Arctic sea ice extent metrics over on the “2023 Minimum Extent” thread. However we’ll start the September open thread ball rolling with a couple of cross posted images.
At the end of August JAXA daily extent was 7th lowest for the date, at 4.49 million km² :
The median prediction of the contributors to the August call by the Sea Ice Prediction Network for the September monthly average extent is 4.6 million km² :
It’s that time of year again! Tony Heller has been asserting that “summer is over at the North Pole” for several weeks now, and the 2023 Arctic sea ice minimum extent will occur at some point over the next four or five weeks. The exact date and level will almost certainly vary from one extent metric to the next.
To get the minimum extent ball rolling, here’s Signe Aaboe’s graph of previous summer minima based on OSI SAF data:
Here too is Zack Labe’s equivalent, based on JAXA data:
We have grandchildren visiting this week, so it seems prudent to get the new open thread started a day early, and before they wake up!
The ARCUS Sea Ice Prediction Network July report has recently been published. Here’s the graphic overview of the 30 predictions for September sea ice monthly average extent:
The July median forecasted value for pan-Arctic September sea-ice extent is 4.66 million square kilometers with interquartile values of 4.51 and 4.87 million square kilometers, while individual forecasts range from 3.12 and 5.30 million square kilometers. We note the lowest forecast is an outlier, and the only forecast that predicts a new record September sea-ice extent value (current record is September 2012, with a sea-ice extent of 3.57 million square kilometers).
After briefly being near the bottom of the historical range at the beginning of the month, AWI’s high resolution AMSR2 area metric is now back near the top of that range:
However, although it’s not visible on the area graph extent has recently taken a bit of a tumble:
Here’s an animation showing the motion of sea ice in the Arctic over the last month:
Data from the Northern Sea Route General Administration web site about the current positions of ships voyaging along the Northern Sea Route reveal that the liquified natural gas carrier Fedor Litke is currently following the icebreaker Sibir through the East Siberian Sea, heading for the Bering Strait:
By way of a change, which is allegedly as good as a rest, let’s start the new month with a very pretty and almost cloud free “pseudo-colour” image of the Lena Delta and adjacent areas of the Laptev Sea:
Laptev sea ice area decline has been in high gear recently:
At the beginning of May AWI’s high resolution AMSR2 extent metric is at the top of the historical range:
After a period of melt in the East Greenland Sea, export of sea ice from the Central Arctic via the Fram Strait has increased recently:
Sea ice area in the Barents Sea peaked in the first week of April and has declined steadily since then:
SMOS data is flowing again, and the gaps have been filled. Here’s the final pre melt ponding map of the spring:
It reveals large areas of thin ice that have recently developed in the Kara Sea. Here’s a pseudo colour glimpse of the region through the clouds:
Arctic sea ice extent in early April is singularly unexceptional. Here’s the AWI AMSR2 version:
Things start to become more interesting when looking at the third dimension. Here’s the PIOMAS gridded thickness map for March 31st:
and the CryoSat-2/SMOS map for the same date:
Note the differing distribution of thick ice north of Greenland and the Canadian Arctic Archipelago between the two maps. Note also the area of thinner ice along the coast of the Beaufort Sea visible on the CS2/SMOS map.
By way of explanation for that phenomenon see the March sea level pressure map from the latest edition of the NSIDC’s Arctic Sea Ice News:
We’ll come on to the Arctic in a moment, but at more temperate latitudes I am proud to announce that my Cornish alter ego has been officially outed as an “environmental campaigner” by the BBC. Moving pictures of yours truly, discussing drought rather than sea ice, are available via BBC iPlayer until around 18:30 this evening, possibly to UK residents only.
[Stop Press! A shorter version of Kirk England’s report on two potential desalination plants in Cornwall (also including my 15 seconds of fame!) is available here until around 22:30 this evening ]
Alternatively we have recorded our own moving pictures of this momentous event:
And an added still image as well:
March has arrived, so it’s time to start taking a serious look at where and when the 2023 maximum Arctic sea ice extent will occur.
To start with here’s Zack Labe’s overview of previous years’ maxima: