Greenland Ice Sheet Daily Melt Extent (1979-Present)

Since 1979, this dataset provides daily (or every-other-day prior to August 1987) binary estimates of wet snow extent on the Greenland ice sheet, derived from passive microwave satellite data using the Cross-Polarized Gradient Ratio method. It serves as a proxy for melt activity, based on brightness temperature changes from SMMR and SSM/I instruments. Data are provided on a 25 km resolution polar stereographic grid in multiple formats, including raw ASCII, binary, and GeoTIFF.

Use Cases

• Analyzing long-term trends in Greenland ice sheet melt onset and duration based on daily binary melt indicators.
• Validating regional climate model outputs against satellite-derived melt extent observations from 1979 onward.
• Correlating annual melt extent anomalies with atmospheric circulation patterns using the gridded time series climatologies.

Strengths

• Provides a continuous, long-term record spanning from 1979 to the present, offering a multi-decadal perspective on melt.
• Derived from a physically-based, peer-reviewed method (Cross-Polarized Gradient Ratio) applied to consistent satellite sensor data (SMMR, SSM/I).

Limitations

• Metadata completeness is low; specific column names, row counts, and author information are not provided across sources.
• The data is a binary proxy for melt state, not a direct quantitative measure of snow wetness or meltwater volume.
• Update dates conflict between sources (2007 vs. 2026), creating uncertainty about the most recent data version or maintenance status.

Provenance

Source

NASA Program for Arctic Regional Climate Assessment (PARCA).

Collection Method

Derived from passive microwave brightness temperature characteristics of the Scanning Multi-channel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) instruments.

Time Range

1979 to present (ongoing).

Freshness

Last updated dates conflict: one source indicates 2007-12-31, another indicates 2026-04-10.

Geography

Greenland ice sheet, gridded on a 60 x 109 pixel Northern Hemisphere polar stereographic projection.