Sea ice is frozen seawater floating on the surface of the ocean, typically averaging a few meters in thickness. Some sea ice is semi-permanent, persisting from year to year, and some is seasonal, melting and refreezing from season to season. This animation shows how the seasonal global sea ice has changed from day to day in both the northern and southern hemisphere since 2002, when the Aqua satellite was launched. This series shows the daily global sea ice over both the Arctic and Antarctic from June 21, 2002 through September 22, 2008. Global data from the AMSR-E instrument on the Aqua satellite is shown on a Cartesian grid. The sea ice extent is derived from the daily AMSR-E 12.5 km sea ice concentration where the ice concentration is above 15%.
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