|October 09, 2014|
Antarctic sea ice reaches record levels, NASA reports
|Sea ice on the southern oceans surrounding the Antarctic has reached record levels, according to NASA scientists, covering the most area since tracking started in 1979.|
But the records being set in the south do not ease scientists' concerns about global warming, saying the gains in the Antarctic are only about a third of what is being lost rapidly in the Arctic, according to Science World Report.
"The planet as a whole is doing what was expected in terms of warming," Claire Parkinson of NASA's Goddard Space Flight Center says in a news release. "Sea ice as a whole is decreasing as expected, but just like with global warming, not every location with sea ice will have a downward trend in ice extent."
According to the news release from NASA, the Arctic has lost an average of 20,800 square miles of ice a year since the late 1970s. The Antarctic has gained an average of 7,300 square miles.
On Sept. 19, Antarctic sea ice extent exceeded 7.72 million square miles for the first time since it's been tracked, according to the National Snow and Ice Data Center. The average maximum extent between 1981 and 2010 was 7.23 million square miles (18.72 million square kilometers).
The single-day maximum extent this year was reached on Sept. 20 when the sea ice covered 7.78 million square miles.
Scientists admit the growing ice in the Antarctic is "a bit of a mystery." Walt Meier, a research scientist at Goddard, says changing weather patterns caused by climate change can bring cooler air to such as the Antarctic, where sea ice circles the continent and covers such a large area it doesn't take that much additional ice extent to set a new record.
Melting ice on the edges of the Antarctic continent could be leading to more fresh, just-above-freezing water, which makes refreezing into sea ice easier, Parkinson said. Or changes in water circulation patterns, bringing colder waters up to the surface around the landmass, could help grow more ice.
"Some people have looked at the Antarctic increasing trend and use that to suggest that global warming isn't happening, or that the increase in the Antarctic is offsetting the decrease in the Arctic and that's simply not true," Meier says in a video on the record extent (see video below). "If you look at the magnitudes of the changes we're seeing in the wintertime, the Arctic is decreasing about twice as fast as the Antarctic is increasing."