MERRA-2: 3-Hourly Global Cloud Diagnostics at 72 Model Layers

NASA's MERRA-2 reanalysis provides global 3-hourly time-averaged cloud diagnostics from 1980 to the present. The dataset contains assimilated variables like cloud fraction for radiation and relative humidity across 72 atmospheric model layers. It is produced by NASA's Global Modeling and Assimilation Office using the GEOS model version 5.12.4.

Use Cases

• Modeling cloud radiative effects based on cloud fraction for radiation data.
• Analyzing atmospheric humidity profiles based on relative humidity fields.
• Studying cloud microphysics based on in-cloud ice and liquid water content.
• Validating satellite-derived cloud properties against assimilated model-level diagnostics.

Strengths

• Data covers a long temporal range from 1980 to present.
• Provides high-resolution 3-hourly time averages.
• Includes data across 72 vertical atmospheric model layers.
• Produced by NASA's Global Modeling and Assimilation Office (GMAO).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data has a latency of approximately 3 weeks after the end of a month.

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 00:51:53.022201; freshness should be verified.

Geography

Global