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Balloon Data Confirms Antarctic Warming Trend

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Posted by lkgeo1 on April 1, 2006, 10:31 pm
 


Balloon Data Confirms Antarctic Warming Trend



 Image: NASA

Launching weather balloons has been a nearly daily habit at some
Antarctic research facilities since 1957. Carrying
radiosondes--instruments that measure atmospheric conditions such as
temperature and wind speed--the balloons travel as high as 12 miles or
more. A new analysis of the past 30 years of records from nine research
stations, including Amundsen-Scott at the South Pole, reveals that the
air above the entirety of Antarctica has warmed by as much as 0.70
degree Celsius per decade during the winter months.
John Turner of the British Antarctic Survey and his colleagues report
in today's issue of Science that this warming trend is consistent
across data from multiple stations run by multiple countries using
multiple types of instruments. Previous studies had shown that
Antarctica's surface temperatures had warmed by roughly 2.5 degrees C
over the last half century, but this study provides the most complete
look at atmospheric trends to date.






"The rapid surface warming of the Antarctic Peninsula and the enhanced
global warming signal over the whole continent shows the complexity of
climate change," Turner says. "Greenhouse gases could be having a
bigger impact in Antarctica than across the rest of the world and we
don't understand why."

This warming has implications for snowfall on the continent as well as
the melting of land-based ice reserves, potentially leading to global
sea-level rise, the researchers warn. Although they cannot ascribe a
particular cause to the warming, they ruled out several other potential
explanations, including heat transfer from other regions (there was no
observed change in wind patterns) and solar radiation changes (the sun
is either at or below the horizon throughout the winter months in
question).
And although current computer models fail to predict this warming
trend, the scientists argue that the data is consistent with what would
be expected as a result of increasing greenhouse gases. "Our next
step," Turner says, "is to try to improve the models." --David Biello


http://www.scientificamerican.com/article.cfm?chanID=sa003&articleID