Daily Ice Cover Time Series (30 years)
Daily Grid files were produced by linear interpolation between consecutive ice charts each winter. Grid files for a given winter (1973 -2002) and source (CIS or NIC) are compressed in a .zip file.
Zip File Name: YYYYNIC-grids.zip and YYYYCIS-grids.zip
YYYY = year (1973 - 2002), NIC
= National Ice Center, CIS
= Canadian Ice Service
YY = winter season (for example, 73 for 1973, 74 for 1974,….02
Grid File Format: 510 records, each record has 516 "grid cells" in I2 format.
Ice Concentration Codes: -1 = land, 0 to 99 = fraction of grid cell covered by ice, expressed as a percent, 100% ice cover was coded as 99 to save room.
Coordinates: The latitude and longitude coordinate of the center of each grid cell is given in the following two fixed formatted text files: Latgrid.zip and Longrid.zip. There are 510 records in each file. The format of each record is: 516 (f 9.5,1x).