Global Snow & Ice - January 2013
NH Snow Cover Extent
|January 2013||Snow Cover Extent||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)
Data were provided by the Global Snow Laboratory, Rutgers University. Period of record is 1967-2013 (47 years).
The Northern Hemisphere snow cover extent (SCE) during January 2013 was 48.64 million square km (18.78 million square miles), 1.88 million square km (730,000 square miles) above average, and the sixth largest January SCE on record. This was the largest January SCE since 2008 when the monthly SCE was 49.8 million square km (19.2 million square miles). Both the Eurasian and North American land areas experienced above-average SCE in January.
During January, the North American SCE was above average, ranking as the 13th largest January snow cover extent on record. The monthly SCE was 17.86 million square km (6.90 million square miles), which was 370,000 square km (142,000 square miles) above average. Above-average SCE was observed across the mountainous West and Northern Plains of the United States. Although much of the western U.S. was drier than average, below-average temperatures during most of the month allowed snow which fell during December to remain on the ground. Below-average snow cover was observed in the Central Plains and parts of the Ohio Valley in the United States. Below-average SCE was also observed in parts of the Great Lakes region of both the U.S. and Canada. For more information on the U.S. January 2013 snow events, please visit the U.S. January Snow/Ice Summary page.
Eurasian SCE was 30.78 million square km (11.88 million square miles), which was 1.51 million square km (579,000 square miles) above average. This marked the sixth largest January SCE on record and the largest since 2008. Above-average snow cover was observed for much of Europe and northeastern China, where several snow storms impacted both regions. Below-average snow cover was present for much of Turkey, Iran, parts of the Tibetan Plateau, and the Himalayas.
Sea Ice Extent
|January 2013||Sea Ice Extent||
(out of 34 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 (34 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 January 2013 was 13.78 million square kilometers (5.32 million square miles), 7.2 percent below the 1979-2000 average. This was the sixth smallest January extent on record but the largest since 2010. The last 10 years have experienced the ten smallest January sea ice extents on record in the Arctic. January 2013 is the 20th consecutive January and 140th consecutive month with below-average Arctic sea ice extent. January Arctic ice extent is decreasing at an average rate of 3.2 percent per decade.
According to analysis by the NSIDC, the Arctic gained approximately 1.36 million square km (525,000 square miles) of ice during January, which was slightly higher than average. The Kara Sea, which has experienced below-average ice coverage for the past several months, was completely ice covered by the end of January. However, the Barents Sea continued to have below-average ice coverage. Below-average ice coverage was also observed for the Gulf of St. Lawrence. On the Pacific side of the Arctic, sea ice extent was slightly above average in the Bering Sea.
The January 2013 Southern Hemisphere sea ice extent was 5.77 million square km (2.23 million square miles), 14.0 percent above average, and the seventh largest January sea ice extent in the 1979-2013 period of record. Much-above-average sea ice extent was observed in the Weddell Sea and the overall Antarctic daily ice extent was nearly two standard deviations above the mean for most of January. Antarctic sea ice extent during January has increased at an average rate of 2.5 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.