Antarctic Snow Constant for 50 Years

Contrary to expectations, there has been no increase in precipitation over Antarctica in the past half-century.

Computer models assessing global climate change call for an increase in Antarctic precipitation as atmospheric temperatures rise. But the most precise record of Antarctic snowfall ever generated shows no change.

But it's unclear what 50 years of data can actually show.

"The year-to-year and decadal variability of the snowfall is so large that it makes it nearly impossible to distinguish trends that might be related to climate change from even a 50-year record," said Andrew Monaghan, a research associate with Ohio State University's Byrd Polar Research Center and lead author of an article on the topic published in the Aug. 10 edition of the journal Science.

"There were no statistically significant trends in snowfall accumulation over the past five decades, including recent years for which global mean temperatures have been warmest," Monaghan said.

The study also suggest thickening of Antarctica's massive ice sheets has not reduced the slow-but-steady rise in global sea levels, as some climate-change critics have argued.

The study looked at both the West Antarctic Ice Sheet (WAIS), a marine ice sheet with a base below sea level, and the much thicker East Antarctic Ice Sheet (EAIS) that sits atop dry land. In recent years, large volumes of ice along the WAIS coast have melted at a faster rate than previously seen. Some observers have argued that global warming is contributing to the melting and the increased calving of icebergs along the continent's margin.

The study was conducted by 16 researchers from nine institutions in seven countries, and it was supported by the National Science Foundation.

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