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Great Lakes Ice Cover Data Set and Climatology Introduction Original Ice Charts First Ice, Last Ice and Ice Duration Daily Ice Cover Time Series Weekly Ice Cover Statistics Questions / Contact GLERL home  
   
 

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


1973 - 1979

1973cis-image.zip
1974cis-image.zip
1975cis-image.zip
1976cis-image.zip
1977cis-image.zip
1978cis-image.zip
1979cis-image.zip


1980 - 1989

1980cis-image.zip
1981cis-image.zip
1982cis-image.zip
1983cis-image.zip
1984cis-image.zip
1985cis-image.zip
1986cis-image.zip
1987cis-image.zip
1988cis-image.zip
1989cis-image.zip
1989nic-image.zip


1990 - 1999

1990cis-image.zip
1990nic-image.zip
1991cis-image.zip
1991nic-image.zip
1992cis-image.zip
1992nic-image.zip
1993cis-image.zip
1993nic-image.zip
1994cis-image.zip
1994nic-image.zip
1995cis-image.zip
1995nic-image.zip
1996nic-image.zip
1997nic-image.zip
1998nic-image.zip
1999nic-image.zip

 


2000 - 2002

2000nic-image.zip
2001nic-image.zip
2002nic-image.zip

 

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.

 

 
 

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