ISLSCP Initiative II | Related Pages |
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ISLSCP Initiative II Home General Data Overview Snow, Sea Ice, Oceans Data Overview |
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ISLSCP Initiative II |
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Snow, Sea Ice, & Oceans Data
This International Satellite Land Surface Climatology Project (ISLSCP)
Initiative 2 data set is based on the Goddard Space Flight Center (GSFC) Sea Ice
Concentrations from Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR)
and the Defense Meteorological Satellites Program (DMSP) Special Sensor
Microwave/Imager (SSM/I) Passive Microwave Data. These original data were re-
gridded by NSIDC from their original 25km spatial resolution and EASE-Grid into
equal angle Earth grids with 1/4, 1/2 and 1 degree spatial resolutions in
latitude/longitude. The ISLSCP2 staff have taken the 1 degree resolution
original data provided by the Principal Investigator and created global maps of
monthly sea ice concentration on a global 1 degree grid using the latitude and
longitude coordinates that were provided. Individual monthly files were created
and written to the ASCII format. The ISLSCP2 staff have also adjusted the re-
gridded 1 degree original data to match the 1 degree ISLSCP2 land/water mask.
The user should always refer to the dataset documentation for more details on
the processing of this dataset.
This data was originally in a yearly tabular format. It was converted to multi-scale maps by plotting each point in the tabular data onto a map of -99 (water) and -88 (land) created from the standard ISLSCP II Land/Sea Masks.
Data Provider: Richard L. Armstrong, Ken Knowles
 Data Files (ISLSCP II Disc #1) |
 Data Set Documentation |
 Image Viewing Tutorial |
There are two kinds of sea ice data files, table data and map data. The original table data are ASCII files and contain gridded monthly sea ice concentrations, in percent, arranged within 10 yearly files.
The map files contain ASCII text at 1 degree (360 values per line, and 180 lines, labeled "1d"), 0.5 degrees (720 values per line, and 360 lines, labeled as "hd"), and 0.25 degrees (1440 values per line, and 720 lines, labeled as "qd"). Each line is terminated by a newline character. These values represent the percentage of days in that month where sea ice was present -- 100 means 100% of the month, 80 means 80% of the month, etc. Missing data is represented by -99 for water and -88 for land. The data are structured so that the upperleft corner of the first pixel is located at 90 North latitude and 180 West longitude.
The data files have all been compressed using the PKZip program.
Each file name is image for a given month.
Example: sea_ice_data_1d_1990.csv contains the sea ice tabular data at 1 degree for all of 1990.
Example: sea_ice_map_1d_19900900.asc contains the sea ice map at 1 degree for September 1990.
Related Pages:
ISLSCP Initiative II Home
General Data Overview
Snow, Sea Ice, Oceans Data Overview
Global Sea Ice Extent Data
Revision Date: April 25, 2003