October 28th, 2018: Arctic sea ice extent ***********************
Unusual warmth continues
Over the Pacific side of the Arctic, a pattern of unusual warmth noted in last month’s post continued. While sea ice extent in the Chukchi and Beaufort Seas remains below average, extent remains especially low on the Atlantic side of the Arctic in the Barents and Laptev Seas. October sea ice extent in the Arctic was the third lowest in the satellite record.
Overview of conditions
Arctic sea ice extent for October 2018 averaged 6.06 million square kilometers (2.34 million square miles), the third lowest October extent in the 1979 to 2018 satellite record. This was 2.29 million square kilometers (884,000 square miles) below the 1981 to 2010 average, and 170,000 square kilometers (66,000 square miles) above the record low recorded for October 2012.
Sea ice gain during the first half of the month was quite slow. By the third week of October, extent was still tracking below all years except 2016. However, toward the end of the month, the pace of ice growth increased.
Ice growth through the month was strong in the Beaufort and Chukchi Seas, but extent remained below average in these areas at the end of the month. A large area of open water remained in the Laptev Sea, which is unprecedented in the satellite record at the end of October. Especially prominent was the lack of ice growth on the Atlantic side of the Arctic in the Barents Sea, and in some regions, a slight contraction of the ice edge further north (Figure 1b). As a result, extent is presently far below average in this area, and is the primary reason why October extent for the Arctic as a whole is third lowest on record.
Image courtesy of the National Snow and Ice Data Center, University of Colorado, Boulder (https://nsidc.org/arcticseaicenews/). Data source see http://nsidc.org/arcticseaicenews/about-the-data/