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.
In 1984, there were 1.86 million square kilometers of old ice spread across the Arctic at its yearly minimum extent. In September 2016, there were only 110,000 square kilometers of old ice left.
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.
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.