Nearly 10 inches (250 millimeters) of snow fell in 2009, a record dumping not seen in the past 60 years, according to snow cores, which were detailed in a separate study published May 10 in the journal Geophysical Research Letters. After July 2009, the weather station saw almost no snowfall until October 2010.
"This sector has the least amount of moisture transported into the continental interior, and all of a sudden it had a very big anomaly in 2009," said Tsukernik, an atmospheric scientist at the National Center for Atmospheric Research in Boulder, Colo.
Tsukernik, who studies Antarctica's cyclones, wanted to see if the spectacular storms somehow caused the sudden uptick in snowfall. With an international team of colleagues, she scanned weather satellite data and discovered a huge water vapor plume heading straight for East Antarctica on May 19, from offshore of Madagascar. "This image looked a hell of a lot like this atmospheric river phenomenon," she said.
The anomaly was several thousand kilometers long but only a few hundred kilometers wide (like a river) and carried lots of water vapor. "This feature in the Southern Ocean very much qualified for all of the parameters of an atmospheric river," Tsukernik said.