2011 marked by high temperatures, low sea ice: WMO Report
Creative Commons: Bo Insogna, 2010
The World Meteorological Organization, the United Nations’ authoritative voice on weather, climate and water has just launched this preliminary statement about the world climate in 2011. As expected, 2011 is on track to be one of the warmest years on record, with the second lowest Arctic sea ice volume.
2011: The warmest La Nina year on record
Global temperatures in 2011 have not been as warm as the record-setting values seen in 2010 but have likely been warmer than any previous strong La Niña year, based on preliminary data from data sources compiled by the World Meteorological Organisation (WMO). The global combined sea surface and land surface air temperature for 2011 (January–October) is currently estimated at 0.41°C ± 0.111°C (0.74°F ± 0.20°F) above the 1961–1990 annual average of 14.00°C/57.2°F. At present, 2011’s nominal value ranks as the equal 10th highest on record, and the 13 warmest years have all occurred in the 15 years between 1997 and 2011. Final annual figures for 2011 will be available once November and December data are available in early 2012.
Global climate in 2011 was heavily influenced by the strong La Niña event which developed in the tropical Pacific in the second half of 2010 and continued until May 2011. This event, which on most measures was one of the strongest of at least the last 60 years, was closely associated with many of the year’s notable regional climate events, including drought in east Africa, the central equatorial Pacific and the southern United States, and flooding in southern Africa, eastern Australia and southern Asia. Strong La Niña years are typically 0.10 to 0.15°C cooler than the years preceding and following them. 2011’s global temperatures followed this pattern, being lower than those of 2010, but were still warmer than the most recent moderate to strong La Niña years, 2008 (+0.36°C), 2000 (+0.27°C) and 1989 (+0.12°C). La Niña conditions have redeveloped in recent weeks but are not expected to approach the intensity seen in late 2010 and early 2011.
Courtesy: World Meteorological Organization, 2011
Surface air temperatures were above the long-term average3 in 2011 over most land areas of the world. The largest departures from average were over Russia, especially in northern Russia where January-October temperatures were about 4°C above average in places. The spring was especially warm in this region with some stations more than 9°C above average for the season, whilst European Russia had another hot summer (the third-hottest on record in Moscow), although not as extreme as that of 2010. The above-average temperatures in most northern polar regions were associated with the second-lowest Arctic sea ice minimum on record.
Record lows for sea ice volume
Arctic sea ice extent was again well below normal in 2011. After tracking at record or near-record low levels for the time of year through the first half of 2011, the seasonal minimum, reached on 9 September, was 4.33 million square kilometres (35% below the 1979-2000 average). This was the second-lowest seasonal minimum on record, 0.16 million square kilometres above the record low set in 2007. Unlike the 2007 season, both the Northwest and Northeast Passages were ice-free for periods during the 2011 summer. Sea ice volume was even further below average and was estimated at a new record low of 4200 cubic kilometres, surpassing the record of 4580 cubic kilometres set in 2010.
Read more: World Meteorological Organization Press Release >>
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