Antarctic Sea Ice

Unlike the Arctic—an ocean basin surrounded by land—the Antarctic is a large continent surrounded by ocean. Because of this geography, sea ice has more room to expand in the winter. But the ice also stretches closer to warmer, lower latitudes, leading to more melting in summer. Antarctic sea ice peaks in September (the end of Southern Hemisphere winter) and retreats to a minimum in February.


1979–2000 mean 18.7 2.9
1999/2000 19.0 2.8
2000/2001 19.1 3.7
2001/2002 18.4 2.9
2002/2003 18.2 3.9
2003/2004 18.6 3.6
2004/2005 19.1 2.9
2005/2006 19.1 2.7
2006/2007 19.4 2.9
2007/2008 19.3 3.9
2008/2009 18.5 2.9
2009/2010 19.2 3.2
2010/2011 19.2 2.5
2011/2012 19.0 3.6
2012/2013 19.4 3.9
2013/2014 19.8 3.8

Since the start of the satellite record, total Antarctic sea ice has increased by about 1 percent per decade. Whether the small increase in extent is a sign of meaningful change is uncertain because ice extents vary considerably from year to year around Antarctica. In September 2012 and 2103, for instance, satellites observed new highs for winter sea ice extent. These new highs occurred while the Arctic was seeing record lows.

There is also variation from place to place around the continent. The Ross Sea sector has had a significant positive trend, while sea ice extent has actually decreased in the Bellingshausen and Amundsen Seas. In short, Antarctic sea ice shows a small positive trend, but large-scale variations make the trend very noisy.




Antarctic Sea Ice

By Rebecca Lindsey
September 1999 & February 2000
Image Location