NH Snow Cover Extent
|November 2014||Snow Cover Extent||1981-2010 Anomaly||Trend
(out of 49 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: 1966–2014 (49 years)
During November 2014, the Northern Hemisphere snow cover extent (SCE) was 36.57 million square km (14.12 million square miles), 2.61 million square km (1.01 million square miles) above the 1981-2010 average and the 5th largest November SCE in the 49-year period of record. This was the sixth consecutive November with above-average snow cover for the hemisphere. The autumn (September-November) SCE was 3.32 million square km (1.3 million square miles) above the 1981-2010 average and the second largest autumn SCE on record for the hemisphere. Only the autumn SCE in 1969 was larger. The 2014 autumn Northern Hemisphere SCE consisted of the third largest September and October SCE and the fifth largest November SCE. This was the sixth consecutive autumn with above-average SCE for the Northern Hemisphere.
The November North American snow cover extent was 15.39 million square km (5.94 million square miles), 1.91 million square km (740,000 square miles) above the 1981-2010 average and the record largest November SCE on record for the continent. This bested the previous record set in 1985 by about 500,000 square km (193,000 square miles), or approximately the size of Spain. This was also the first November that the monthly SCE exceeded 15.00 million square miles (5.79 million square miles). During the month, most of the contiguous U.S. and Canada were much cooler than average, contributing to the largest November SCE for the contiguous U.S. and the second largest for Canada. The largest November SCE for Canada occurred just last year. Conversely, Alaska was much warmer than average, and the state had its fifth smallest November SCE. Overall, the southern two-thirds of Canada and most of the contiguous U.S. had above-average SCE, while below-average SCE was observed in the American Southwest and western Alaska.
For the autumn season, the North American SCE was 1.26 million square km (230,000 square miles) above average and the second largest September-November SCE on record. The largest autumn SCE for North America occurred in 1969. This was the fifth consecutive autumn with above-average SCE for North America.
The Eurasian November SCE was 21.18 million square km (8.18 million square miles), 710,000 square km (280,000 square miles) above average. This was the 15th largest November SCE. Above-average SCE was observed across northern Scandinavia, central and eastern Russia, central and northwestern China, much of Kazakhstan, and the Himalayas. Below average SCE was observed across central and eastern Europe, Mongolia, and much of the Tibetan Plateau.
The autumn Eurasian SCE was 2.06 million square km (500,000 square miles) above average and the fourth largest on record, marking the sixth consecutive autumn with above average SCE and the largest seasonal SCE since 1976.
Sea Ice Extent
|November 2014||Sea Ice Extent||
(out of 36 years)
|million km2||million mi2||Year(s)||million km2||million mi2|
Data Source: National Snow and Ice Data Center (NSIDC). Period of record: 1979–2014 (36 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 November 2014 was 10.36 million square km (4.00 million square miles), 630,000 square km (240,000 square miles), or 5.73 percent, below the 1981-2010 average, and the ninth smallest November extent in the 36-year satellite record; however, it was also this was the largest since 2008. The Arctic sea ice extent grew at a near-average rate during November, gaining 2.15 million square km (830,000 square miles) of ice. Below-average ice extent was observed on the Pacific side of the Arctic, especially in the Chukchi Sea which was ice free for much of November. Near-average ice was observed across much of the Atlantic side of the Arctic. November Arctic sea ice extent is decreasing at an average rate of 4.6 percent per decade.
The November 2014 Southern Hemisphere sea ice extent was 16.63 million square km (6.42 million square miles), 330,000 square km (130,000 square miles), or 2.02 percent, above the 1981-2010 average, ranking as the eighth largest November Antarctic sea ice extent on record. Sea ice in the Southern Hemisphere has rapidly declined over the past few months after reaching a record-large extent in September. According to the NSIDC, large ice reductions in the Bellingshausen Sea and the southern Indian Ocean were the main causes of the Antarctic-wide decrease, driven in large part by persistent northerly winds. November Southern Hemisphere sea ice extent is increasing at an average rate of 0.9 percent per decade.
When combining the Northern Hemisphere and Southern Hemisphere sea ice extents, the globally-averaged sea ice extent during November was 26.99 million square km (10.42 million square miles), 1.10 percent below the 1981-2010 average and the 13th smallest November global sea ice extent on record. Global sea ice extent during November is decreasing at an average rate of 1.3 percent per decade.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.