Released on December 18, 2008
Sea ice is frozen seawater floating on the surface of the ocean. Some sea ice is semi-permanent, persisting from year to year, and some is seasonal, melting and refreezing from season to season. The sea ice cover reaches its minimum extent at the end of each summer and the remaining ice is called the perennial ice cover.
In this animation, the globe slowly rotates one full rotation while the Arctic sea ice and seasonal land cover change throughout the years. The animation begins on September 21, 2005 when sea ice in the Arctic was at its minimum extent, and continues through September 20, 2008. This time period repeats twice during the animation, playing at a rate of one frame per day. Over the terrain, monthly data from the seasonal Blue Marble Next Generation fades slowly from month to month. Over the water, Arctic sea ice changes from day to day. This is a modification of animation ID #3404 : Global Rotation showing Seasonal Landcover and Arctic Sea Ice, which only covered a one-year time period.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 188.8.131.52.0