Friday, July 22, 2016

Will more snow over Antarctica offset rising seas? Don't count on it

Public Release: 19-May-2016
Will more snow over Antarctica offset rising seas? Don't count on it
University of Washington

Many factors related to warming will conspire to raise the planet's oceans over coming decades -- thermal expansion of the world's oceans, melting of snow and ice worldwide, and the collapse of massive ice sheets.

But there are a few potential brakes. One was supposed to be heavier snowfall over the vast continent of Antarctica. Warmer air will hold more moisture and thus generate more snow to fall inland and slightly rebuild the glacier, according to climate model projections.
Not so fast, says a University of Washington study published in Geophysical Research Letters, a journal of the American Geophysical Union. The authors looked at evidence from the West Antarctic Ice Sheet Divide ice core to get a first clear look at how the continent's snowfall has varied over 31,000 years.

"It's allowed us to look at the snow accumulation back in time in much more detail than we've been able to do with any other deep ice core in Antarctica," said lead author T.J. Fudge, a UW postdoctoral researcher in Earth and space sciences. "We show that warmer temperatures and snowfall sometimes go together, but often they don't."

For example, the record includes periods before 8,000 years ago, as Earth was coming out of its last ice age, when the air temperature went up by several degrees without any boost in the amount of snowfall.


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