MERRA-2: NASA Global Aerosol Diagnostics, 1980-Present

NASA's MERRA-2 reanalysis provides monthly diurnal means of assimilated aerosol diagnostics from 1980 onward. The collection includes column mass density for components like black carbon, dust, sea salt, sulfate, and organic carbon, plus aerosol optical thickness at 550 nm. Produced by NASA's Global Modeling and Assimilation Office, the data is updated with a latency of about three weeks after each month.

Use Cases

• Modeling long-term trends in particulate matter (PM1.0, PM2.5, PM10) based on derived formulas for aerosol components.
• Analyzing diurnal patterns of aerosol optical thickness at 550 nm for atmospheric visibility studies.
• Assessing global distribution and concentration of specific aerosol types like black carbon and sulfate.
• Validating satellite-derived aerosol measurements against assimilated model diagnostics.
• Studying the impact of sea salt and dust aerosols on regional climate and air quality.

Strengths

• Data covers a long temporal range from 1980 to the present.
• Includes multiple specific aerosol components: black carbon, dust, sea salt, sulfate, and organic carbon.
• Provides hourly time-stamped monthly means for diurnal analysis.
• Produced by NASA's Global Modeling and Assimilation Office using the GEOS 5.12.4 model.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and dataset size are unknown, which may limit suitability assessment.
• Data may reflect geographic or temporal bias inherent to the model assimilation process.

Provenance

Source

National Aeronautics and Space Administration (NASA) Global Modeling and Assimilation Office

Collection Method

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

Time Range

1980-present

Freshness

Updated with a latency of ~3 weeks after the end of a month; last metadata update was 2026-03-13.

Geography

Global, at 0.625 x 0.5 degree resolution.