MERRA-2: Hourly Cloud Properties from Satellite Simulator, 1980-Present

MERRA-2's hourly cloud simulator data provides parameters like ISCCP total cloud area fraction and MODIS cloud particle size means. NASA's Global Modeling and Assimilation Office produces this global atmospheric reanalysis using the GEOS model version 5.12.4. The dataset covers from 1980 to the present with a latency of approximately three weeks.

Use Cases

• Validate cloud feedback models based on CFMIP Observations Simulator Package parameters.
• Analyze global cloud fraction trends based on hourly time-averaged ISCCP and MODIS data.
• Compare simulated cloud particle properties against direct satellite measurements.
• Study diurnal cycles of cloud coverage based on hourly timestamps starting at 00:30 UTC.

Strengths

• Covers a long temporal range from 1980 to the present.
• Provides hourly time-averaged data with timestamps at the central time of each hour.
• Includes specific parameters like MODIS cloud fraction low, mid, and high mean.
• Produced by NASA GMAO using the GEOS version 5.12.4 model.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data reprocessing has occurred, and filename conventions differ for reprocessed files.

Provenance

Source

National Aeronautics and Space Administration, Global Modeling and Assimilation Office

Collection Method

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

Time Range

1980-present

Freshness

Last updated 2026-03-13 00:29:42.821953; freshness should be verified.

Geography

Global, at 0.625 x 0.5 degree resolution