MERRA-2 M2TUNXCHM: Monthly Diurnal Means of Carbon Monoxide and Ozone Diagnostics

Monthly diurnal means of assimilated carbon monoxide and ozone diagnostics from NASA's MERRA-2 global atmospheric reanalysis. The dataset covers the period from 1980 to the present, with a latency of approximately three weeks after each month. It is produced by NASA's Global Modeling and Assimilation Office using the GEOS version 5.12.4 model.

Use Cases

• Analyze diurnal patterns of carbon monoxide column burden based on hourly time-averaged data.
• Model chemical production of carbon monoxide based on assimilated diagnostic fields.
• Study trends in total column ozone based on monthly mean data spanning decades.
• Validate atmospheric chemistry models based on assimilated surface concentration data.

Strengths

• Data spans from 1980 to the present, providing a long-term historical record.
• Produced by NASA's Global Modeling and Assimilation Office, an authoritative source.
• Provides hourly data fields timestamped from 00:30 to 23:30 UTC for diurnal analysis.

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; filename conventions differ for reprocessed files.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Assimilated from satellite-era observations using the GEOS version 5.12.4 model.

Time Range

1980-present

Freshness

Last updated 2026-03-13 00:50:56.597446; freshness should be verified.

Geography

Global, at a 0.625 x 0.5 degree spatial resolution.