Arctic sea ice minimum for 2024 reached

Alan Bailey

for Petroleum News

The National Snow and Ice Data Center has reported that on Sept. 11 the Arctic sea ice likely reached its minimum extent for this year. The ice extent of 1.65 million square miles was the seventh lowest over the nearly 46 years that satellite records of the sea ice coverage have been obtained -- the 18 lowest sea ice extents have all occurred in the last 18 years. However, there is a possibility that a late-season storm could further reduce the ice extent. And there is some remaining uncertainty over the exact date of the minimum, NSIDC said.

(See map in the online issue PDF)

The sea ice minimum was 344,000 square miles higher than the satellite-era record minimum extent of 1.31 million square miles measured on Sept. 17, 2012. It was 749,000 square miles below the average minimum extent measured from 1981 to 2010.

This downward trend amounts to a 12.4% decline per decade, with an average sea ice loss of about 30,000 square miles per year -- that is equivalent to the loss of the area of Austria or South Dakota annually, NSIDC said.

In early September NSIDC reported that unusually warm conditions over the Barents Sea related to winds from the south. However, air temperatures at 2,500 feet above the ocean surface were 4F to 7F below average over most of the Arctic Ocean. Imagery from a Japanese microwave scanning radiometer indicated that ice concentrations remained fairly low over much of the ocean. Imagery from a NASA spectroradiometer in late August indicated lower sea ice concentration and apparent open water near the North Pole. However, at that time surface refreezing was expected as air temperatures dropped below freezing, NSIDC reported.

--ALAN BAILEY