Sea Ice Extent
According to the National Snow and Ice Data Center (NSIDC), the Northern Hemisphere sea ice extent — which is measured from passive microwave instruments onboard NOAA satellites — averaged for June 2011, was 11.01 million square km (4.25 million square miles), 9.44 percent below the 1979-2000 average. This marks the second smallest June Arctic sea ice extent since records began in 1979. The record smallest June Arctic sea ice extent occurred in 2010, when the monthly average Arctic sea ice extent was 10.87 million square km (4.2 million square miles). June 2011 marks the 20th consecutive June and the 121st consecutive month with below-average Arctic sea ice extent. Arctic sea ice extent was below average across much of the Arctic, including Hudson Bay, the Bering Sea, the Newfoundland Sea, the Barents Sea, and the Kara Sea. The southern Kara Sea, which is typically still ice covered by the end of June, was completely ice free. June Arctic sea ice extent has decreased at an average rate of 3.6 percent per decade.
The June 2011 Southern Hemisphere sea ice extent was 0.56 percent below the 1979-2000 average. This is the 12th smallest (22nd largest) June Southern Hemisphere sea ice extent on record. The June 2011 Antarctic ice extent is significantly smaller than the June 2010 extent, which was the largest on record and 8.33 percent above average. June Antarctic sea ice extent has increased at an average rate of 1.2 percent per decade, although there is considerable interannual variability. During June, Antarctic sea ice continued its annual growth cycle, after reaching its annual minimum extent at the end of February.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.