AIRS Satellite Mid-Tropospheric CO2 8-Day Gridded Retrievals

The AIRS instrument aboard NASA's Aqua satellite provides mid-tropospheric carbon dioxide concentration data averaged into 2.5x2 degree grid cells. Each file covers an 8-day period, containing mean values, standard deviations, and counts of individual retrievals per grid box. This Level 3 gridded product is managed by NASA's GES DISC.

Use Cases

• Analyzing spatial patterns of mid-tropospheric CO2 concentrations using the gridded mean values.
• Assessing retrieval uncertainty for climate models by referencing the standard deviation maps per grid cell.
• Tracking changes in CO2 levels over time by comparing sequential 8-day files.
• Validating ground-based or model-derived CO2 estimates against satellite observations.
• Studying CO2 distribution between latitudes -60 and +90 degrees using the geospatial grid.

Strengths

• Data originates from the AIRS grating spectrometer, a high-resolution (R=1200) instrument on a dedicated satellite platform.
• Each grid cell provides a standard deviation and a count of input retrievals, enabling statistical assessment of the mean.
• The dataset has a cross-platform presence on NASA EarthData and Data.gov, indicating its importance and official status.
• The spatial grid is well-defined, covering longitudes from -180.0 to +180.0 and latitudes from -60.0 to +90.0 degrees.

Limitations

• The last update date conflicts between sources: NASA EarthData lists 2017-02-21, while Data.gov lists a future date of 2026-03-13.
• Key metadata such as row count, file size, and specific column names are not provided on any platform.
• The license is unclear; NASA EarthData does not specify, while Data.gov lists 'other-license-specified'.

Provenance

Source

NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

Collection Method

Retrievals from the Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite, averaged and binned into 8-day, 2.5x2 degree grids.

Time Range

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Freshness

2017-02-21 23:59:59.999000

Geography

Global coverage from -180.0 to +180.0 degrees longitude and -60.0 to +90.0 degrees latitude.