MERRA-2 Monthly Diurnal Land Surface Diagnostics

MERRA-2 tavgU_2d_lnd_Nx provides monthly diurnal means of land surface diagnostics from NASA's global atmospheric reanalysis. The dataset includes hourly time-averaged fields such as baseflow flux, runoff, and soil temperature across six layers, covering the period from 1980 to the present. It is produced by NASA's Global Modeling and Assimilation Office using the GEOS version 5.12.4 model.

Use Cases

• Modeling soil moisture dynamics using surface soil wetness and root zone soil wetness fields across hourly timestamps.
• Analyzing hydrological fluxes by correlating baseflow flux and runoff data with precipitation events.
• Studying soil thermal profiles through soil temperature data at six different depth layers.
• Investigating diurnal cycles in land surface variables by comparing hourly means from 00:30 to 23:30 UTC.
• Validating land surface models against reanalysis data for fields like water at surface layer and water at root zone layer.

Strengths

• Provides continuous global coverage from 1980 to present, offering over 40 years of historical data.
• Includes multiple diagnostic layers, specifically soil temperature at six distinct depths.
• Offers hourly diurnal resolution with time-stamped data for each hour of the day.
• Generated by a well-documented NASA reanalysis system, GEOS version 5.12.4.

Limitations

• Data has a latency of approximately three weeks after the end of each month, limiting real-time analysis.
• The spatial resolution is 0.625 x 0.5 degrees, which may be coarse for regional-scale studies.
• Reprocessing events change file names, complicating version tracking and data continuity.

Provenance

Source

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

Collection Method

Generated by the Goddard Earth Observing System Model (GEOS) version 5.12.4 atmospheric reanalysis assimilation.

Time Range

1980-present

Freshness

Updated monthly with a latency of ~3 weeks.

Geography

Global coverage at 0.625 x 0.5 degree resolution.