Below-average maximum for Arctic ice

Kristen Nelson

Petroleum News

figures for the winter extent of Arctic sea ice, released March 26 by the National Snow and Ice Data Center, indicate Arctic sea ice likely reached its maximum extent March 14 at 5.8 million square miles, the 14th lowest maximum extent in the 46-year satellite record.

(See map in the online issue PDF)

"While this year's maximum extent was not among the lowest in our records, the long-term decrease in extent continues," said NSIDC senior research scientist Walt Meier. "The winter maximum is not a good indicator of summer sea ice conditions, which are influenced by the thinner ice that now dominates the Arctic as well as spring and summer weather. For example, this year's maximum is lower than 2012, when the summer minimum extent set a record low."

NSIDC said this year's maximum extent is 247000 square miles below the 1981 to 2010 average maximum of 6.04 million square miles and 232,000 square miles above the lowest maximum of 5.56 million square miles set March 7, 2017.

Since the maximum on March 14, extent has dropped some 62,000 square miles and the agency said the maximum number is preliminary, as continued winter conditions could push the ice extent higher. A full analysis will be issued in early April.

The downward linear trend from 1979 to 2024 is 15,400 square miles per year, 2.5% per decade relative to the 1981 to 2010 average, NSIDC said. Based n those values, maximum extent has declined 691,000 square miles since 1979, equivalent to the size of Alaska or five times the size of Germany.

--KRISTEN NELSON