Antarctic sea ice is at record- high levels, but researchers are quick to point out that such conditions do not refute knowledge of global warming. Antarctica reached a total ice extent of 7.78 million square miles on Sept. 20, breaking a record set just one year before.
This sea ice is floating on water, and should not be confused with the frozen covering seen on the land. Those packs of ice are melting faster than expected.
This unusual buildup of sea ice around Antarctica suggests that complex processes may be affecting water around the continent. One theory holds that changing air patterns over the frozen continent are blowing cold winds out over the Southern Ocean, leading to the formation of ice. Another idea holds that fresh liquid water, released by melting glaciers on land, could be draining into the waterway. This would lower salt concentrations in the ocean, leading to greater quantities of frozen water. Additional research could reveal the process fueling creation of sea ice.
"There hasn't been one explanation yet that I'd say has become a consensus, where people say, 'We've nailed it, this is why it's happening.' Our models are improving, but they're far from perfect," Claire Parkinson, a senior scientist at NASA's Goddard Space Flight Center, said.
Near the North Pole, Arctic sea ice continues to recede with each passing season. The smallest amount of ice ever measured was seen in 2012, and this year was the sixth-lowest on record. The rate at which ice is disappearing in the Arctic is three times faster than it is building in the Southern Hemisphere. Sea ice, measured worldwide, has decreased since the start of the industrial revolution.
"The planet as a whole is doing what was expected in terms of warming. 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," Parkinson said.
Many factors affect the formation of sea ice in Polar Regions. These include water salinity, snowfall amounts, cloud cover, the ever-changing ozone hole and many other unpredictable conditions.
"It's really not surprising to people in the climate field that not every location on the face of Earth is acting as expected - it would be amazing if everything did. The Antarctic sea ice is one of those areas where things have not gone entirely as expected. So it's natural for scientists to ask, 'OK, this isn't what we expected, now how can we explain it?'" Parkinson stated in a NASA press release.