MERRA-2 M2IMNXGAS: Monthly Aerosol Optical Depth Analysis

MERRA-2 M2IMNXGAS is an instantaneous 2-dimensional monthly mean data collection for aerosol optical depth analysis. The dataset is produced by NASA's Global Modeling and Assimilation Office using the GEOS model version 5.12.4. It covers the period from 1980 to the present, with a latency of approximately three weeks after the end of each month.

Use Cases

• Analyze long-term trends in aerosol optical depth based on monthly mean assimilation data
• Study the variance of atmospheric aerosol parameters based on the included variance fields
• Validate satellite-derived aerosol measurements against the assimilation analysis
• Model atmospheric radiative forcing based on aerosol optical depth analysis increments

Strengths

• Produced by NASA's Global Modeling and Assimilation Office, an authoritative source
• Covers a long temporal range from 1980 to the present
• Provides both analysis and analysis increment fields for aerosol optical depth

Limitations

• Column-level documentation is absent; field semantics must be inferred after download
• Row count is unknown, which may limit suitability assessment
• Data reprocessing may result in filename changes, requiring careful version tracking

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Assimilation produced by NASA GMAO using the Goddard Earth Observing System Model (GEOS) version 5.12.4.

Time Range

1980-present

Freshness

Updated monthly with a latency of ~3 weeks after the end of a month.

Geography

Global, 0.625 x 0.5 degree resolution