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 series shows the global sea ice throughout 2005, when the maximum extent occurred on March 7th and the minimum extent occurred on September 21st. Here global data from the AMSR-E instrument on the Aqua satellite is shown on a Cartesian grid. The false color in these images is derived from the daily AMSR-E 6.25 km 89 GHz brightness temperature while the sea ice extent is derived from the daily AMSR-E 12.5 km sea ice concentration.
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 126.96.36.199.0