Northern Hemisphere Monthly Snow Cover Extent from Satellite Observations

1966 to 2001 satellite-derived data shows monthly snow cover extent across the Northern Hemisphere at multiple spatial scales (1.0, 0.5, and 0.25 degree). This dataset, derived from the NSIDC EASE-Grid product and provided by NASA, represents the percentage of days with snow present each month. It was the first combined representation of snow and sea ice measurements from satellites for this period.

Use Cases

• Analyzing long-term trends in monthly snow cover percentage using the gridded snow extent values.
• Modeling seasonal fluctuations and creating monthly climatologies of snow probability and variance.
• Validating climate or hydrological models against historical satellite observations of snow presence.
• Studying the combined cryosphere by examining snow cover data alongside sea ice extent (1978-2001).

Strengths

• Provides a long temporal record, with snow cover data spanning 35 years from 1966 to 2001.
• Offers data at three spatial resolutions (1.0, 0.5, and 0.25 degree) for analysis at multiple scales.
• Derived from the first satellite-based combined snow and sea ice extent product, providing a foundational record.

Limitations

• Key metadata such as row count, column names, and exact file size are unavailable from all sources.
• Sources conflict on the 'last updated' date, with one listing 1995-12-31 and others listing 2026-03 13.
• Missing data is encoded with sentinel values (-99 for water, -88 for land), which requires preprocessing.

Provenance

Source

National Aeronautics and Space Administration (NASA), derived from the National Snow and Ice Data Center (NSIDC) Northern Hemisphere EASE-Grid product.

Collection Method

Satellite observations converted from yearly tabular format to multi-scale geospatial maps using an ISLSCP II land/sea mask.

Time Range

1966-06-01 to 2001-06-30

Freshness

2026-03-13 01:32:20.188219

Geography

Northern Hemisphere land areas.