NSIDC's Polar Stereographic Projection was originally designed to be optimal for sea ice applications, though it is now used for many other products. It specifies a projection plane or grid tangent to the Earth's surface at 70° N/S (Figure 1), which means that the grid cells at 70° latitude are exactly equal to the nominal grid resolution. This translates to a 6% distortion of the grid at the poles but means there is little or no distortion of the grid in near the marginal ice zones. Many data sets archived at NSIDC, including many brightness temperature and sea ice products, use the NSIDC Polar Stereographic Projection precisely because of this minimal distortion around the marginal ice zone.

Figure 1. Northern Hemisphere (left) and Southern Hemisphere (right) NSIDC Polar Stereographic Projection coverage maps.


To learn more about projections and grids, including the polar stereographic grids discussed here, please refer to the following:

Knowles, Kenneth W. 1993. Points, Pixels, Grids, and Cells: A Mapping and Gridding Primer. Unpublished report to the National Snow and Ice Data Center, Boulder, CO USA.

Pearson, F. 1990. Map projections: Theory and applications. CRC Press. Boca Raton, Florida. 372 pages.

Snyder, J. P. 1987. Map projections - a working manual. U.S. Geological Survey Professional Paper 1395. U.S. Government Printing Office. Washington, D.C. 383 pages.

Snyder, J. P. 1982. Map Projections Used by the U.S. Geological Survey. U.S. Geological Survey Bulletin 1532.