The National Snow and Ice Data Center recently reported that the Antarctic has experienced an annual increase in sea ice averaging 7,300 square miles, covering 7.72 square miles–a record extent since data commences in 1979. This is in sharp contrast to the mean yearly loss of Arctic sea ice (20,800 square miles).
Climate scientists who observe and quantify glacial changes in the polar regions are not certain what has caused an increase in Antarctic sea ice. Possibilities include changes in the ozone layer above Antarctica, storm track and more powerful winds circulating around the region, confining ice in a favorable growth region.
Ohio State University atmospheric scientists keep a close track on the weather in the Antarctic Peninsula, and created a polar version of a numerical weather model (WRF) in the past decade. Ohio State research associate John Mercer, who joined the Institute of Polar Studies (now Byrd Polar Research Center) in 1960, was the first to propose a link melting of the West Antarctic Ice Sheet to rising global sea levels and temperatures in the 1970s.
Much uncertainty surrounds the behavior of Antarctic sea ice. Climate experts see the gradual loss of the West Antarctic Ice Sheet as irreversible, despite increasing ice coverage in the Ross Sea and other areas, due to complex factors resulting in different glacial responses.