MERRA-2 M2T3NXGLC: 3-Hourly Land Ice Surface Diagnostics

1980-present time series of assimilated land ice surface diagnostics produced by NASA's Global Modeling and Assimilation Office (GMAO). The dataset provides 3-hourly time-averaged values for variables like fractional glaciated snow cover, snow mass, and snow depth, starting from 01:30 UTC. It is part of the MERRA-2 global atmospheric reanalysis and is updated with a latency of approximately three weeks after the end of each month.

Use Cases

• Modeling snow mass changes over glaciated surfaces based on the snow mass variable.
• Analyzing temporal patterns of snow cover extent based on the fractional area of glaciated surface snow cover.
• Studying snowpack densification processes based on the total snow mass residual due to densification.
• Validating hydrological models using snow depth over glaciated surface data.
• Assessing climate reanalysis performance for cryosphere components using the assimilated diagnostics.

Strengths

• Data covers a long temporal range from 1980 to the present.
• Provides high temporal resolution with 3-hourly time-averaged values.
• Produced by NASA GMAO using the GEOS version 5.12.4 model, indicating a authoritative source.
• Includes specific land ice surface diagnostics like snow mass and snow depth.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic or temporal bias inherent to the reanalysis model.

Provenance

Source

National Aeronautics and Space Administration (NASA) Global Modeling and Assimilation Office (GMAO)

Collection Method

Assimilated global atmospheric reanalysis using the Goddard Earth Observing System Model (GEOS).

Time Range

1980-present

Freshness

Updated with a latency of ~3 weeks after the end of a month; last metadata update was 2026-03-13.

Geography

Global, with a spatial resolution of 0.625 x 0.5 degree.