Monthly average polar sea-ice concentration 1978 through 1991

This data set represents the results of calculations carried
out on sea-ice-concentration data from the SMMR and SSM/I
instruments. The original data were obtained from the
National Snow and Ice Data Center (NSIDC). The data set also
contains the source code of the programs that made the
calculations. The objective was to derive monthly averages
for the whole 13.25-year series (1978-1991) and to derive a
composite series of monthly averages representing the
variation of an average year. The resulting file set contains
monthly images for each of the polar regions for each year,
yielding 160 files for each pole, and composite monthly
averages in which the years are combined, yielding 12 more
files. Averaging the images in this way tends to reduce the
number of grid cells that lack valid data; the composite
averages are designed to suppress interannual variability.
Also included in the data set are programs that can retrieve
seasonal ice-concentration profiles at user-specified
locations. These nongraphical data retrieval programs are
provided in versions for UNIX, extended DOS, and Macintosh
computers. Graphical browse utilities are included for the
same computing platforms but require more sophisticated
display systems.