New York: Warm temperatures have led to record decline in the extent of sea ice in the Arctic and off the coast of Antarctica in November this year, say scientists.
While unusually high air temperatures and a warm ocean have led to a record low Arctic sea ice extent, in the Southern Hemisphere, Antarctic sea ice extent also hit a record low for the month, caused by moderately warm temperatures and a rapid shift in circumpolar winds, the researchers said.
“It looks like a triple whammy — a warm ocean, a warm atmosphere, and a wind pattern all working against the ice in the Arctic,” said Mark Serreze, Director, National Snow and Ice Data Center (NSIDC) at University of Colorado Boulder in the US.
Arctic sea ice extent averaged 9.08 million square km for November, 1.95 million square km below the 1981 to 2010 long-term average for the month.
Although the rate of Arctic ice growth was slightly faster than average, total extent actually decreased for a brief period in the middle of the month.
The decrease in extent measured 50,000 square kilometers and was observed mostly in the Barents Sea, an area of the Arctic Ocean north of Norway, Finland, and Eastern Russia.
The scientists said the decrease in extent is almost unprecedented for November in the satellite record — a less pronounced and brief retreat of 14,000 square kilometers happened in 2013.
November 2016 is now the seventh month this year to have hit a record low extent in the 38-year satellite monitoring period, the researchers pointed out.
In the Southern Hemisphere, sea ice surrounding the continent of Antarctica declined very quickly early in the month and set a record low.
The average extent for November was 14.54 million square kilometres, 1.81 million square kilometres below the 1981 to 2010 average.
“Antarctic sea ice really went down the rabbit hole this time,” NSIDC lead scientist Ted Scambos said in a statement issued by University of Colorado Boulder.