Monthly Diurnal Land Ice Surface Diagnostics from NASA MERRA-2 Reanalysis

MERRA-2 tavgU_2d_glc_Nx provides monthly diurnal means of assimilated land ice surface diagnostics, such as fractional glaciated snow cover and snow mass. This data collection is produced by NASA's Global Modeling and Assimilation Office using the GEOS model and covers the period from 1980 to the present. Data are timestamped at 3-hour intervals starting from 01:30 UTC.

Use Cases

• Modeling ice sheet surface mass balance using snow mass over glaciated surface and total snow mass residual due to densification fields.
• Analyzing seasonal snow cover variability on glaciers using the fractional area of glaciated surface snow cover data.
• Studying diurnal cycles in land ice surface properties across the 3-hourly timestamps (01:30, 04:30, etc.).
• Validating regional climate models against assimilated snow depth over glaciated surface diagnostics.
• Investigating long-term trends in glaciated snow mass from the continuous record starting in 1980.

Strengths

• Continuous global record from 1980 to present, updated with ~3 week latency.
• Data assimilated from observations using NASA's GEOS model version 5.12.4.
• Provides diurnal means at 3-hour intervals for detailed temporal analysis.
• Covers key land ice surface variables like snow mass and fractional snow cover.

Limitations

• Spatial resolution is 0.625 x 0.5 degrees, which may be coarse for local glacier studies.
• Data is reprocessed periodically, requiring users to check for version changes and filename differences.
• Assimilated model output contains uncertainties inherent to the reanalysis methodology.

Provenance

Source

NASA Global Modeling and Assimilation Office (GMAO) via the GES DISC.

Collection Method

Assimilated reanalysis produced using the Goddard Earth Observing System Model (GEOS) version 5.12.4.

Time Range

1980 to present.

Freshness

Updated monthly with a latency of approximately three weeks.

Geography

Global coverage at 0.625 x 0.5 degree resolution.