It’s been a hot summer in North America and the northern Hemisphere, and it looks like the sea ice in the Arctic Ocean is feeling the heat.
Since 1979 satellites have tracked the amount of sea ice in the Arctic Ocean. As you would expect, some of the ice melts every summer. The annual “sea ice minimum” usually occurs in early to mid-September.
This week it appears the coverage of sea ice in the Arctic Ocean is at or near the all-time record low set in 2007.
The details form the national Snow and Ice Data Center.
Arctic sea ice near record lows
“Arctic sea ice extent averaged for August 2011 reached the second lowest level for the month in the 1979 to 2011 satellite record. Both the Northwest Passage and the Northern Sea route appear to be open. Throughout August, sea ice extent tracked near the record lows of 2007, underscoring the continued decline in Arctic ice cover.
Note: Arctic sea ice extent will likely reach its minimum extent for the year sometime in the next two weeks. NSIDC will make a preliminary announcement when ice extent has stopped declining and has increased for several days in a row. Monthly data for September will be released in early October.
Overview of conditions
Average ice extent for August 2011 was 5.52 million square kilometers (2.13 million square miles). This is 160,000 square kilometers (61,800 square miles) above the previous record low for the month, set in August 2007, and 2.15 million square kilometers (830,000 square miles), or 28% below the average for 1979 to 2000. Sea ice coverage remained below normal everywhere except the East Greenland Sea. In addition, several large areas of open water (polynyas) have opened within the ice pack.
On August 31, 2011 Arctic sea ice extent was 4.63 million square kilometers (1.79 million square miles). This is 100,000 square kilometers (38,600 square miles) higher than the previous record low for the same day of the year, set in 2007. As of September 5, ice extent had fallen below the minimum ice extents in September 2010 and 2008 (previously the third- and second-lowest minima in the satellite record). If ice stopped declining in extent today it would be the second-lowest minimum extent in the satellite record.
Higher-resolution Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) data processed by the University of Bremen showed ice extent on September 5 as falling below the same date in 2007.”