The image above shows melting of Arctic sea ice extent over the last 20 days, July 5 to 25, 2020.  At the bottom right, the shallow Hudson Bay goes to water rapidly, losing 500k km2 of ice.  Even so, at 172k km2 that region is nearly average.  The remarkable 2020 event is the effect of high Siberian temperatures causing extensive melting of the nearby shelf seas, seen on the left vertical. Already on July 5, Laptev was mostly water, and now has only 5% ice. Neighboring seas East Siberian and Kara also melted rapidly. The other feature is Baffin Bay, center right, losing 300k km2 to retain only 7% of its maximum ice extent.

The graph below shows the ice extent retreating during July compared to some other years and the 13 year average (2007 to 2019 inclusive).

Note that the  MASIE NH ice extent 13 year average loses about 2.6M km2 during July, down to 7M km2. MASIE 2020 started nearly 500k km2 lower and lost ice at a higher rate, now 1.1M km2 below average.  Both MASIE and SII show this year below other recent years, reaching the present ice extent 7 days ahead of 2019 and 14 days ahead of average.

The table shows where the ice is distributed compared to average.  Bering and Okhotsk are open water at this point no longer shown in these updates. The deficit of 1.1M km2 represents 15% of the total, or an ice extent melting 14 days ahead of average.

Note that all of the deficit to average is accounted for by the Russian shelf seas of East Siberian, Laptev and Kara, along with Baffin Bay

Illustration by Eleanor Lutz shows Earth’s seasonal climate changes. If played in full screen, the four corners present views from top, bottom and sides. It is a visual representation of scientific datasets measuring Arctic ice extents.