Daily Ice Cover Time Series (30 years)
Introduction | Animations | Daily Grids | Daily Images | Daily Lake & River Averages
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.
Daily Grids
Zip File Name: YYYYNIC-grids.zip and YYYYCIS-grids.zip
YYYY = year (1973 - 2002), NIC
= National Ice Center, CIS
= Canadian Ice Service
Each .zip file has 182 Grid files. The Grid file name encodes the date
and type of data: no data, interpolated data, or observed data. Grids
prior to the date of the first and after the last ice chart each winter
are coded zero.
YY = winter season (for example, 73 for 1973, 74 for 1974,….02
for 2002)
ddd = day of the winter season (101=Dec 1, ...132=Jan 1, …282=May
31)
I = data indicator: I = 0 (no data), I = 1 (interpolated data), I = 2
(observed data)
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).
Introduction | Original
Ice Charts | First Ice,
Last Ice & Ice Duration | Daily
Ice Cover Time Series
Weekly Ice Cover Statistics
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