This map shows sea ice extent around Antarctica on September 22, 2013, when ice covered more of the Southern Ocean than at any other time in the satellite record.
These satellite-based maps show sea ice concentration in the Arctic and Antarctic during September 2008 and February 2009, the months of the sea ice maximums and minimums in the respective hemispheres.
This pair of images shows Antarctic sea ice concentrations at the 2008 winter maximum and the 2009 summer minimum compared to the median ice extent from 1979–2000.
New elevation measurements will give researchers an unprecedented understanding of the thickness of sea ice, which will be used to help improve climate modeling and forecasts.
Since satellites began monitoring sea ice in 1979, researchers have observed a decline in the average extent of Arctic sea ice in every month of the year.
The extent of Arctic sea ice peaked at 15.24 million square kilometers on March 18, 2012. It was the ninth consecutive year of maximum extents below the long-term average.