Great Lakes Ice Concentration Grids from Digitized Historical Charts

Over 2800 historical ice charts were digitized to create this geospatial data base of ice concentration grids for the Great Lakes. The dataset was provided by the NOAA Great Lakes Environmental Research Laboratory (GLERL) to the National Snow and Ice Data Center (NSIDC). It captures a continuous 20-year record of winter ice conditions from 1960 through 1979.

Use Cases

• Analyzing long-term trends in winter ice cover extent across Lake Superior, Michigan, Huron, Erie, and Ontario.
• Validating and calibrating regional climate or lake ice models using historical concentration grids.
• Correlating historical ice conditions with atmospheric circulation patterns from the same period.
• Studying the interannual variability of ice formation and melt timing for each lake.

Strengths

• Derived from a substantial foundation of over 2800 original ice charts, providing dense temporal sampling.
• Covers a consistent and significant 20-year time period (1960-1979) for trend analysis.
• Sourced from the authoritative NOAA Great Lakes Environmental Research Laboratory (GLERL).
• Has a cross-platform presence on Data.gov and NASA Earthdata, indicating recognized importance.

Limitations

• The exact data structure, column names, and row counts are not documented on any platform.
• There is a conflict in the 'last updated' metadata: Data.gov lists 2026 (likely an administrative placeholder), while NASA Earthdata lists 1979.
• The specific terms of the 'other-license-specified' are not provided.

Provenance

Source

NOAA Great Lakes Environmental Research Laboratory (GLERL), Ann Arbor, MI, provided to NSIDC.

Collection Method

Digitization of over 2800 historical ice concentration charts.

Time Range

1960 to 1979

Freshness

1979-05-01 23:59:59.999000

Geography

The Great Lakes (Superior, Michigan, Huron, Erie, Ontario).