Update from April 20, 2008
BLOGGER'S NOTE: Leon from Holland has posted a comment linking to this graph (please click to enlarge) from the National Snow and Ice Data Center, Boulder, Colorado:Link to graph: http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png
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by Liz Kalaugher, environmental research web, April 18, 2008
In summer 2007 the Arctic experienced record ice loss. So the big questions now are, how well did the ice recover over the winter and how likely is another record minimum in ice extent this summer?
Having thrown these two queries into the mix at the European Geosciences Union General Assembly in Vienna, Julienne Stroeve of the National Snow and Ice Data Center at the University of Colorado, US, proceeded to detail the latest thinking.
"The ice loss penetrated much further into the central area than ever seen before [in summer 2007]," said Stroeve. "There was some recovery in the extent of winter ice in 2007/2008 but it was still well below normal."
According to Stroeve, there were also anomalies in ice concentration, with levels above normal in the east and below normal in the west.
This spring, first-year ice made up 72% of the Arctic basin, compared to the 2007 spring level of 59%. Stroeve says this is partly because so much ice melted last summer, but also because of a return to a positive Arctic oscillation, which exports older ice out of the Arctic basin.
This is potentially a problem because younger ice is thinner and will melt out more easily. What's more, satellite measurements indicate that first-year ice is 5-10 cm thinner this year than last, and that older ice is thinner this year too.
So what could this mean for summer 2008? Stroeve says it seems like the Arctic is heading for a very low extent ice year, whether it's a record or not. And what happens will depend on natural variability in atmospheric circulation patterns.
About the author
Liz Kalaugher is editor of environmentalresearchweb.
Link to article (free registration required): http://environmentalresearchweb.org/cws/article/research/33829
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