Global Snow & Ice - March 2013
NH Snow Cover Extent
|March 2013||Snow Cover||1981-2010 Anomaly||Trend
(out of 47 years)
|million km2||million mi2||million km2||million mi2||million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: Global Snow Laboratory, Rutgers University. Period of record: 1967–2013 (47 years)
The Northern Hemisphere snow cover extent (SCE) during March 2013 was 41.14 million square km (15.88 square miles), 1.30 million square km (0.5 million square miles) above the 1981-2010 average. This was the 16th largest March SCE on record. Both the North American and Eurasian land areas had an above-average March SCE. March Northern Hemisphere snow cover extent is decreasing at an average rate of 440,000 square km (170,000 square miles) per decade.
During March, the North American SCE was above average, ranking as the sixth largest March SCE on record. The monthly SCE was 16.54 million square km (6.38 million square miles), which was 0.98 million square km (380,000 square miles) above average. This was the largest March SCE for North America since 1979. Above-average snow cover was observed across much of the eastern U.S., and the Canadian Prairie Provinces and Rockies. Below-average snow coverage was present for most of the western United States. March SCE across North America is decreasing at an average rate of 60,000 square km (20,000 square miles) per decade.
Eurasian SCE was 24.60 million square km (9.50 million square miles), 320,000 square km (120,000 square miles) above average, and the 22nd largest March SCE on record. Above-average snow cover was present for much of western and central Europe and northeastern China. Below-average snow cover was observed across central China and Mongolia, Kazakhstan, Iran, Turkey, and the Balkans. Eurasian SCE during March is decreasing at an average rate of 390,000 square km (150,000 square miles) per decade.
Sea Ice Extent
(out of 35 years)
|million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2013 (35 years)
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 March 2013 was 15.04 million square km (5.81 million square miles), 2.92 percent below the 1981-2010 average, and the fifth smallest March sea ice extent on record. The monthly extent was 610,000 square km (236,000 square miles) above the record low for the month, which occurred in 2006. March Arctic sea ice extent is decreasing at an average rate of 2.6 percent per decade. During the month, most regions of the Arctic region had below-average sea ice extent with the exception of the Bering Sea, which had slightly more ice coverage compared to average for this time of year.
On March 15th the Arctic sea ice reached its annual maximum extent at 15.13 million square km (5.84 million square miles), which is 510,000 square km (197,000 square miles) below the 1981-2010 average maximum extent. This marks the end of the annual growth season and beginning of the annual melt cycle, which typically ends in September when the Arctic sea ice extent reaches its annual minimum extent. During the entire 2012-2013 growth season, the Arctic sea ice extent grew by a record 11.72 million square km (4.53 million square miles), driven largely by the record small sea ice extent which occurred in September 2012. The 2013 annual maximum extent was the sixth smallest on record, the ten smallest maximum extents have occurred in the last ten years, between 2004 and 2013.
The March 2013 Southern Hemisphere sea ice extent was 5.32 million square km (2.05 million square miles), 20.77 percent above the 1981-2010 average, marking the second largest March extent on record. March 2008 had a larger monthly sea ice extent for the Antarctic region. March Southern Hemisphere sea ice extent is increasing at an average rate of 3.9 percent per decade, with substantial interannual variability.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.