September 19, 2012
Arctic Cyclone Breaks Up Sea Ice
Watch how the winds of a large Arctic cyclone broke up the thinning sea ice cover of the Arctic Ocean in early August 2012. The storm likely contributed to the ice cap’s shrinking to the smallest recorded extent in the past three decades.
The frozen cap of the Arctic Ocean likely reached its annual summertime minimum extent and broke a new record low on Sept. 16, the National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder has reported. Analysis of satellite data by NASA and the NASA-supported NSIDC showed that the sea ice extent shrunk to 1.32 million square miles (3.41 million square kilometers), or 293,000 square miles less than the previous lowest extent in the satellite record, set in mid-September, 2007.
“Climate models have predicted a retreat of the Arctic sea ice; but the actual retreat has proven to be much more rapid than the predictions,” said Claire Parkinson, a climate scientist at NASA Goddard Space Flight Center, Greenbelt, Md. “There continues to be considerable interannual variability in the sea ice cover, but the long-term retreat is quite apparent.”
This year, the cyclone formed off the coast of Alaska and moved on Aug. 5 to the center of the Arctic Ocean, where it churned the weakened ice cover for several days. The storm cut off a large section of sea ice north of the Chukchi Sea and pushed it south to warmer waters that made it melt entirely. It also broke vast extensions of ice into smaller pieces more likely to melt.
“The storm definitely seems to have played a role in this year’s unusually large retreat of the ice,” Parkinson said. “But that exact same storm, had it occurred decades ago when the ice was thicker and more extensive, likely wouldn’t have had as prominent an impact, because the ice wasn’t as vulnerable then as it is now.”
Sea ice data courtesy of the Defense Meteorological Satellite Program. Wind data courtesy of the National Centers for Environmental Prediction.
Visualization credit: Scientific Visualization Studio/NASA Goddard Space Flight Center