October 5, 2011
Last month the extent of sea ice covering the Arctic Ocean declined to the second-lowest extent on record. Satellite data from NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder showed that the summertime sea ice cover narrowly avoided a new record low.
The September 9, 2011 ice cover, the lowest this year, was second in recorded history after 2007’s record melting. The yellow line shows the 30-year average ice cover – much bigger chunk of ice melted this year. The Northwest Passage shipping line is seen fully open (path in red line). Credit- NASA Goddard’s Scientific Visualization Studio
Although the July level of ice was record low, the Arctic sea ice cover this year was second only to 2007. According to NASA, on the lowest Arctic ice cover day, Sept. 9, a total of 4.33 million square kilometers of ice was observed in the Arctic. The average area of ice on the month of September 4.61 million square kilometers, also the second only in the recorded history.
Hence, 2011 saw the second lowest ice extent both for the daily minimum extent and the monthly average. When compared to the average ice cover from the years 1979 to 2000, this year’s cover was 2.43 million square kilometers less.