Released on September 25, 2004
This animation shows the global advance and retreat of daily snow cover along with daily sea ice surface temperature over the Northern Hemisphere from September 2002 through May 2003. The snow cover was measured by the MODIS instrument on the Terra satellite, while the sea ice surface temperature was measured by the MODIS instrument on the Aqua satellite. Since these instruments cannot take measurements through clouds, in cloud-covered regions or areas with suspect data quality, the prior day's value is retained until a valid data reading is obtained. This visualization designates an area as covered by snow when the instrument takes a valid measurement showing greater than ~50% snow coverage in that area. This area is assumed to be snow covered until the instrument takes a valid measurement showing less than 40% snow coverage in that same area. A color bar indicates the sea ice surface temperature values. The satellite instruments are unable to collect data through darkness. The region in polar darkness is shown as a gray cap over the pole that grows and shrinks seasonally. A date slider indicates the progression of time. SeaWiFS Land Reflectance shows the seasonal changes in land cover.
This animation shows the daily advance and retreat of snow cover, and sea ice surface temperature over the Northern Hemisphere during the
winter of 2002-2003. Snow cover over the tip of South America is also shown during the summer of 2000.
This color bar shows the colors used to represent the sea ice surface temperature. The coldest water is shown in light blue. The warmest sea ice is shown in shades of pink. As the sea ice surface temperatures cool
below -15 degrees Celsius, the color is shown in shades of purple. The sea ice
surface below -28 degrees Celsius is shown in shades of blue-grey.
Please give credit for this item to: NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio. NOTE: All SeaWiFS images and data presented on this web site are for research and educational use only. All commercial use of SeaWiFS data must be coordinated with GeoEye (NOTE: In January 2013, DigitalGlobe and GeoEye combined to become DigitalGlobe).
Short URL to share this page: http://svs.gsfc.nasa.gov/2981
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 18.104.22.168.0