NOAA's National Centers for Environmental Information
NH Snow Cover Extent
Data were provided by the Global Snow Laboratory, Rutgers University. Period of record is 1967-2010 (44 years).
The average Northern Hemisphere snow cover extent during February 2010 was 2.8 million square kilometers above average, resulting in the third largest February snow cover extent on record, behind 1978 and 1972. The average Northern Hemisphere February snow cover extent for the 1967-2010 period of record is 45.6 million square kilometers. Snow cover extent during the Northern Hemisphere December 2009 - February 2010 was 2.4 million square kilometers above the 1967-2010 average and the second largest Northern Hemisphere winter snow cover extent on record, behind 1978. The 44-year average Northern Hemisphere winter snow cover extent for the period of record is 45.2 million square kilometers.
Across North America, snow cover for February 2010 was 1.5 million square kilometers above average—the third largest February snow cover extent since satellite records began in 1967, behind 1978 and 1979. During much of the month, the contiguous U.S. was pummeled by multiple winter storms that brought heavy snow to the nation, resulting in numerous records—please see the February 2010 Snow and Ice report for more information. In contrast, Wawa, Ontario, Canada, received a total of 13 cm (5.1 inches) of snowfall—setting a new record low snowfall. The previous record was set in 1942 when just 13.2 cm (5.2 inches) of snow fell. The average February snowfall in the area is 54.5 cm (21.5 inches) (Source: Environment Canada). The average North American snow cover extent for both February and December-February period is 17.1 million square kilometers for the period of record. Snow cover for December 2009 - February 2010 was 1.3 million square kilometers above average and the largest snow cover extent since records began.
The average Eurasian snow cover extent during February 2010 was 1.3 million square kilometers above average, the tenth-largest snow cover extent on record. The 44-year average Eurasian snow cover extent in February is 28.5 million square kilometers for the period of record. Eurasia's snow cover extent during December 2009 - February 2010 was the fourth largest such snow cover extent on record, 1.1 million square kilometers above average. The 44-year average Eurasian snow cover extent in winter is 28.1 million square kilometers for the period of record.
Sea Ice Extent
For a twelfth consecutive February, the Arctic sea ice extent was below average. According to the National Snow and Ice Data Center (NSIDC), the February 2010 Northern Hemisphere sea ice extent—which is measured from passive microwave instruments onboard NOAA satellites—was 14.6 million square kilometers (6.8 percent or 1.1 million square kilometers below the 1979–2000 average), resulting in the fourth lowest February sea ice extent since satellite records began, behind 2005, 2006, and 2007. It was reported that unusually low sea ice extent was observed in the Atlantic area; however, it was above normal in the Bering Sea. February Arctic sea ice extent has decreased at an average rate of 2.9 percent per decade since 1979. Arctic sea ice usually expands during the cold season to a March maximum, then contracts during the warm season to a September minimum.
Meanwhile, the Antarctic reached its minimum extent for the year. The February 2010 Southern Hemisphere sea ice extent was 7.3 percent or 88,500 square kilometers above the 1979–2000 average. This was the eighth largest sea ice extent in February. Southern Hemisphere sea ice extent for February has increased at an average rate of 3.1 percent per decade. Antarctic sea ice usually expands during the cold season to a September maximum, then contracts during the warm season to a March minimum.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page, provided by NOAA's National Snow and Ice Data Center (NSIDC).