Global Snow & Ice - October 2013
NH Snow Cover Extent
|October 2013||Snow Cover||1981-2010 Anomaly||Trend
(out of 46 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 (46 years)
October marks the beginning of the cold season for the Northern Hemisphere and storms begin bringing snow to the higher latitudes and elevations. During October 2013, the Northern Hemisphere snow cover extent (SCE) was 21.0 million square km (8.1 million square miles), which was 3.5 million square km (1.3 square miles) above the 1981-2010 average of 17.5 million square km (6.8 million square miles). This marked the seventh largest October SCE in the 46-year satellite record and the largest October SCE since 2009.
Across North America, the SCE during October 2013 was above average — the contiguous U.S. had much above-average SCE, Canada had above-average SCE, and Alaska had below-average SCE. The continentally-averaged October SCE was 8.2 million square km (3.2 million square miles), 111,000 square km (42,000 square miles) above the 1981-2010 average, and the 20th largest October SCE in the 46-year period of record. Regionally, the north-central United States, in addition to central and eastern Canada, had above-average snow cover during October. Much of Alaska and northwestern Canada had below-average October snow cover.
Eurasian SCE was above average during October, with a spatial extent of 12.9 million square km (5.0 million square miles), 3.4 million square km (1.3 million square miles) above the 1981-2010 average, and the fourth largest October SCE on record. This was the largest October SCE since 2002 for Eurasia. During October, most of Russia, Mongolia, and the Tibetan Plateau had above-average snow cover. Below-average snow cover was observed in the northern regions of India, Pakistan, and Afghanistan.
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 October 2013 was 8.10 million square kilometers (3.13 million square miles), 9.09 percent below the 1981-2010 average, and the 6th lowest October extent in the 35-year period of record. Over the course of the month ice grew at a rate faster than average with the Arctic gaining 3.21 million square km (1.24 million square miles) of new ice. Even though the Arctic sea ice extent was below average, it was the largest since 2008, when the October Arctic sea ice extent was 8.42 million square km (3.25 million square miles). During October, the Beaufort, Chukchi, and Kara seas had below-average ice coverage, while the rest of Arctic had near-average ice cover. October Arctic sea ice extent is decreasing at an average rate of 7.1 percent per decade.
The October 2013 Southern Hemisphere sea ice extent was 19.43 million square km (7.5 million square miles), 5.98 percent above the 1981-2010 average, and the largest October Antarctic sea ice extent on record. The previous record large October sea ice extent occurred in 2006 when the monthly average Antarctic sea ice extent was 18.99 million square km (7.33 million square miles). October Southern Hemisphere sea ice extent is increasing at an average rate of 1.1 percent per decade, with substantial interannual variability.
When combining the Northern Hemisphere and Southern Hemisphere sea ice extents, the globally-averaged sea ice extent during October was 27.53 million square km (10.63 million square miles), 1.06 percent above the 1981-2010 average, tying with 1990 as the 13th largest October global sea ice extent on record. This marked the first October since 2006 with above-average global sea ice extent and the largest since 1999.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page.