Monday, April 5, 2010

Arctic Sea Ice Extent returns to average trend

During March 2010 sea ice extent has continued to grow bucking the trend of a slow reduction in sea ice at this time of year. Sea Ice Extent is just below the 1979-2000 average sea ice extent. This data is still in accord with the long term trend of reduction in arctic sea ice.

One of the indicators of rapid global warming in polar regions is the area covered by winter and summer sea ice - the Sea Ice Extent. Other indicators are average thickness of sea ice and how much is 1st year ice as against older multi-year ice.

According to a report in the UK Telegraph - Arctic ice increased during freezing winter - the usual pattern of winds has changed around the North Pole resulting in more cold air than usual in lower latitudes. This pattern is known as the Arctic Oscillation, which has been in a strong negative phase this northern winter bringing freezing temperatures and snow to lower latitudes - a colder winter for North America, Britain and Europe.

Dr Mark Serreze, Director of the National Snow and Ice Data Centre (NSlDC), said the sea ice continued to grow through March but that other areas of the arctic were warmer than normal. 'What this doesn't show is any indication that global warming is over. If you look at the Arctic as a whole we might get to average amounts of sea ice for the time of year. But the ice is thin and quite vulnerable and it can melt very quickly.' he said.
You can see land surface tempature mapped for December, January and February at the NASA Earth Obervatory Page - Temperature Anomalies, Winter 2009-2010. These maps show clearly the results of the negative phase of the Arctic Oscillation with warmer temperatures in Newfoundland, Greenland, Alaska and eastern Siberia, while lower latitudes are much cooler.

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Takver is a citizen journalist from Melbourne who has been writing on Climate Change issues and protests including Rising Sea Level, Ocean acidification, Environmental and social Impacts since 2004.