Nimbus-7 SMMR Polar Gridded Radiances and Sea Ice Concentrations
This data set contains gridded brightness temperatures and sea ice concentrations for both polar regions. It spans the period from October 1978 through August 1987, when the Nimbus-7 SMMR scanner was turned off. The data were collected every other day at 6.60, 10.69, 18.00, 21.00 and 37.00 GHz. Due to spacecraft power limitations, the scanner operated only on alternate days. There are usually at least foutreen days of coverage per month, although major data gaps occurred during the month of August. In August 1982, the following days are missing for both polar regions: 4th, 8th, and 16th; in August 1984, the 13th through the 23rd are missing for both polar regions; and in August 1985, the 6th through 8th are missing for the Southern Hemisphere.
Brightness temperature and sea ice concentration grids have 25 x 25 km grid elements in polar stereographic projection. Volume 7 contains all SMMR sea ice concentrations for both polar regions, plus five months of brightness temperature grids for the North polar region.
Brightness temperature grids are stored as 16-bit integers, one day of brightness temperature data is 0.27 mbytes for the North polar region, 0.21 mbytes for the South. Ice grids are stored as 8-bit integers. Files contain 136192 bytes and 104912 bytes for the North and South respectively. The NASA Team Algorithm (Cavalieri et al. 1984, Gloersen and Cavalieri 1986) was used to calculate ice concentrations from the brightness temperatures. The data were produced by Dr. P. Gloersen, NASA/GSFC, Oceans and Ice Branch, and are available via FTP.
Notice to Data Users: SMMR TCT tapes comprised the input data set, unlike the SMMR Digital Media product distributed by NSIDC in 1979.
The following example shows how to cite the use of this data set in a publication. For more information, see our Use and Copyright Web page.
Gloersen, P. 2006. Nimbus-7 SMMR Polar Gridded Radiances and Sea Ice Concentrations. [indicate subset used]. Boulder, Colorado USA: NASA DAAC at the National Snow and Ice Data Center.