Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Arctic Sea Ice at Highest Minimum Since 2014

The last 15 years have had the lowest September extents in the record

The summer melt season has come to a modest end: Summer 2021 was relatively cool compared to the most recent years, and the September extent was the highest since 2014, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder, part of CIRES. It was nevertheless an eventful summer, with many twists and turns.

Arctic sea ice extent for September averaged 4.92 million square kilometers (1.90 million square miles), the twelfth lowest in the 43-year satellite record. This is 1.35 million square kilometers (521,000 square miles) above the record low set in September 2012, and 1.49 million square kilometers (575,000 square miles) below the 1981 to 2010 average. The last 15 years (2007 to 2021) have had the 15 lowest September extents in the record.

The annual minimum extent occurred on September 16 and was the twelfth lowest minimum in the satellite record. Afterwards, ice extent increased primarily in the Beaufort Sea region, with the large irregular open water region that existed in mid-September filling in with ice. The ice edge also expanded in the East Siberian Sea. The East Greenland Sea has been largely ice free for much of the summer, but sea ice is now expanding southward.

Read the full report from NSIDC


CIRES is a partnership of NOAA and CU Boulder.

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