NOAA's National Centers for Environmental Information
NH Snow Cover Extent
Analyses of NOAA data were provided by the Global Snow Laboratory, Rutgers University. Period of record is 1967-2010.
During March 2010, snowfall across the Northern Hemisphere was variable. In North America, warmer-than-average temperatures led to rapid snow melt, while parts of Eurasia had below-average temperatures and above average snow cover extent. These conditions contributed to a near average Northern Hemisphere snow cover extent. The average Northern Hemisphere snow cover extent during March 2010 was 0.3 million square kilometers above average, resulting in the 18th largest March snow cover extent on record. The average Northern Hemisphere March snow cover extent for the 1967-2010 period of record is 40.3 million square kilometers.
Across North America, snow cover extent for March 2010 was below average, the eighth lowest extent since satellite records began in 1967. The average North American March snow cover extent is 15.7 million square kilometers for the 1967-2010 period of record. The low cover extent across the continent can be attributed to the anomalously warm conditions that enveloped much of North America, resulting in rapid snow melt. According to Environment Canada, many locations across Ontario, Canada received no snow or traces of snow during March 2010—setting new low snowfall records. Toronto City, which typically receives 22 cm (8.7 inches) of snow during March recorded no snow this year. This broke the low snowfall record which dates as far back as 1898. For information on the U.S. March 2010 snow events, please visit the U.S. 2009-2010 Snow Season Summary page.
Unlike the past four years, the average Eurasian snow cover extent during March 2010 was 1.0 million square kilometers above average, the tenth-largest snow cover extent on record. The 44-year average Eurasian snow cover extent in March is 24.6 million square kilometers for the period of record. The above-average snow cover extent might be attributed to the below-average conditions that engulfed parts of Eurasia. According to Beijing Climate Center (BCC), parts of China had heavy snow and frost during March 2010, resulting in more than 4.8 billion yuan (703 million U.S. dollars) in direct economic losses.
Sea Ice Extent
Arctic sea ice usually expands during the cold season to a March maximum, then contracts during the warm season to a September minimum. According to the National Snow and Ice Data Center (NSIDC), the March 2010 Northern Hemisphere sea ice extent—which is measured from passive microwave instruments onboard NOAA satellites—was 15.1 million square kilometers (4.1 percent or 650,000 square kilometers below the 1979–2000 average), resulting in the fifth least sea ice extent since records began in 1979. This was also the 17th consecutive March with below-average Arctic sea ice extent. The maximum Arctic sea ice extent during March 2010 occurred on March 31st—the latest date for the maximum sea ice extent since records began in 1979. The previous record for latest date was set on March 29, 1999. By March 31st the maximum extent for the year reached 15.2 million square kilometers, which was near the 1979-2000 average levels for this time of the year. The record low sea ice extent for March was set in 2006. March Arctic sea ice extent has decreased at an average rate of 2.6 percent per decade since 1979.
The Antarctic sea ice extent usually expands during the cold season to a September maximum, then contracts during the warm season to a March minimum. Unlike the two previous years which were above average, the March 2010 Southern Hemisphere sea ice extent was 6.9 percent below the 1979–2000 average. This was the eighth least sea ice extent in March. Southern Hemisphere sea ice extent for March has increased at an average rate of 4.0 percent per decade.
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).