Here’s the latest graph of Arctic sea ice extent from JAXA/ViSHOP, with 2021 and 2015 highlighted:
Extent fell by over 100,000 square kilometres between February 16th and 17th! Can that steep fall continue, as it did for one more day in 2015?
Here too is Zack Labe’s 2021 overview of JAXA maximum extent over the previous couple of decades:
2015’s maximum was very early, on February 15th. Hence the current extremely tentative 2021 maximum is already both higher and later than that. The decadal average extent graphs show the date of the maximum getting later and later, and the 2010’s peaks in the middle of March.
It therefore seems likely that there is more freezing still to come this year. However lets take a look at the high resolution AMSR2 sea ice area graph for the Sea Of Okhotsk:
The recent fall in Arctic wide extent has evidently been driven by the recent rapid decline in this peripheral sea, where SMOS reveals more thin ice ripe for further melting:
In conclusion, the high res AMSR2 extent metric shows the tentative 2021 peak below that of 2015!
March 2019 has arrived, which in recent years has proved to be by far the likeliest month to contain the maximum extent of Arctic sea ice for the year. To begin with, here’s our favourite high resolution extent graph calculated by “Wipneus” from University of Hamburg/JAXA AMSR2 data:
September is upon us once again, the month in which the assorted Arctic sea ice area and extent metrics (almost) always reach their respective annual minima. Now we are free to start speculating about what the assorted minima will be, and on what date.
According to the latest edition of the National Snow and Ice Data Center’s “Arctic Sea Ice News”
On March 17, 2018, Arctic sea ice likely reached its maximum extent for the year, at 14.48 million square kilometers (5.59 million square miles), the second lowest in the 39-year satellite record, falling just behind 2017. This year’s maximum extent is 1.16 million square kilometers (448,000 square miles) below the 1981 to 2010 average maximum of 15.64 million square kilometers (6.04 million square miles).
September has arrived once again, the month in which the assorted Arctic area and extent metrics (almost) always reach their respective annual minima. Now we can start to speculate about what the assorted minima will be, and on what date.
It’s far too early to be sure about this yet, but it’s not beyond the bounds of possibility that the 2017 maximum is already in place. Here’s our favourite high resolution extent graph calculated by “Wipneus” from University of Hamburg/JAXA AMSR2 data:
As you can see, global sea ice extent has just reached the lowest ever level in the National Snow and Ice Data Center’s satellite records going back to 1979. It was over a month later when the previous record was broken in February 2016, so there is plenty of time for the metric to fall further.