Daily Ice Cover Time Series (30 years)

Introduction | Animations | Daily Grids | Daily Images | Daily Lake & River Averages

Daily Image files of color-coded ice concentrations over the Great Lakes were produced from the Daily Grid files. Image files for a given winter (1973 -2002) and source (CIS or NIC) are compressed in a .zip file.

Daily Images

Zip File Name: YYYYNIC-image.zip and YYYYCIS-image.zip
YYYY = year (1973 - 2002), NIC = National Ice Center, CIS = Canadian Ice Service

Each .zip file has 182 image files. The image 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.

Image File Names: YYdddI.png

YY = winter season (for example, 73 = 1973, 74 = 1974…. 02 = 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).
png. = Image file format.

Introduction | Original Ice Charts | First Ice, Last Ice & Ice Duration | Daily Ice Cover Time Series
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