November 12, 2012
Shifting Wind Patterns Behind Increase In Sea Ice In Antarctica
redOrbit Staff & Wire Reports - Your Universe Online
While global warming has caused extensive melting of sea ice in the Arctic region in recent years, the opposite phenomenon has been occurring in Antarctica, and now experts believe they've discovered the reason why.In a report released Sunday, a team of scientists revealed that shifting wind patterns surrounding the southernmost continent have resulted in slight increase in regional sea ice. That conclusion comes following an extensive analysis of nearly 20 years worth of measurements obtained from American military satellites, said Damian Carrington of The Guardian.
Scientists from the British Antarctic Survey (BAS) and NASA's Jet Propulsion Laboratory (JPL) collaborated on the research, which the Wall Street Journal said was based on more than five million daily ice-motion measurements recorded by four different satellites that are part of the U.S. Defense Meteorological Satellite Program (DMSP).
"Until now these changes in ice drift were only speculated upon, using computer models of Antarctic winds," lead author Dr. Paul Holland of the BAS said of the study, according to the website PhysOrg. "This study of direct satellite observations shows the complexity of climate change."
"The total Antarctic sea-ice cover is increasing slowly, but individual regions are actually experiencing much larger gains and losses that are almost offsetting each other overall," he added. "We now know that these regional changes are caused by changes in the winds, which in turn affect the ice cover through changes in both ice drift and air temperature. The changes in ice drift also suggest large changes in the ocean surrounding Antarctica, which is very sensitive to the cold and salty water produced by sea-ice growth."
Holland and collaborator Ron Kwok of the California-based NASA facility on the project detail their work in this week's edition of the journal Nature Geoscience.
While northward winds are causing slight growth in ice levels near the South Pole, Bloomberg News reporter Justin Doom notes that ice levels in the Arctic reached their smallest total amount ever earlier this year.
The ice cap in the Arctic dipped to 3.41 million square kilometers on September 16, he said -- the lowest number recorded in 33 years of satellite observation there, according to the Colorado-based US National Snow and Ice Data Center (NSIDC).
"The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent," Kwok told Carrington on Sunday.