MERRA-2 M2IUNXASM: Global Atmospheric Reanalysis with Hourly Diurnal Means

MERRA-2 is a global atmospheric reanalysis produced by NASA's Global Modeling and Assimilation Office using the GEOS model version 5.12.4. The M2IUNXASM collection provides instantaneous 2-dimensional monthly diurnal means of assimilated meteorological diagnostics at single levels, such as temperature, wind, surface pressure, and precipitable water. The dataset covers the period from 1980 to the present, with data latency of approximately three weeks after the end of each month.

Use Cases

• Modeling diurnal temperature cycles based on 2-meter and 10-meter temperature data
• Analyzing wind patterns based on wind components at 2-meter, 10-meter, and 50-meter levels
• Studying atmospheric moisture content based on total precipitable water measurements
• Investigating surface pressure variability for climate research

Strengths

• Data is produced by NASA's Global Modeling and Assimilation Office, an authoritative source
• Covers a long temporal range from 1980 to the present
• Provides hourly resolution within monthly diurnal means (00:00 to 23:00 UTC)
• Includes multiple meteorological parameters at different vertical levels

Limitations

• Column-level documentation is absent; field semantics must be inferred after download
• Data reprocessing history is documented separately, requiring manual verification
• Row count is unknown, which may limit suitability assessment

Provenance

Source

National Aeronautics and Space Administration

Collection Method

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

Time Range

1980-present

Freshness

Last updated 2026-03-13 00:30:32.015154; freshness should be verified

Geography

Global