AIRX3C2M: Mid-Tropospheric CO2 from Aqua Satellite

NASA's AIRS/Aqua L3 Monthly CO2 dataset provides gridded retrievals of mid-tropospheric carbon dioxide concentrations. Data is derived from the Atmospheric Infrared Sounder and AMSU instruments aboard the Aqua satellite, representing a sensitivity-weighted average peaking between 6-10 km altitude. Each monthly file contains gridded mean values, standard deviations, and observation counts at a 2.5x2 degree resolution.

Use Cases

• Tracking global and regional trends in mid-tropospheric CO2 based on monthly gridded means.
• Validating atmospheric transport models using the dataset's spatial coverage from -60 to +90 degrees latitude.
• Assessing retrieval uncertainty for specific grid cells using the provided standard deviation maps.
• Analyzing data density and sampling frequency per region using the integer counts map.

Strengths

• Provides a long-term, spatially consistent record from a well-characterized satellite instrument (AIRS/AMSU on Aqua).
• Includes uncertainty metrics (standard deviation) and data density information (counts) for each grid cell.
• Has a defined spatial resolution (2.5x2 degrees) and sensitivity profile (peaks 6-10 km), clarifying the data's representativeness.

Limitations

• Metadata conflicts exist: one platform shows a last update date of 2026-04-10, while another shows 2012-02-29, creating uncertainty about data currency.
• The dataset's sensitivity is weighted to the mid-troposphere (6-10 km), so it does not represent total column or surface CO2 concentrations.
• Specific column names, file sizes, and row counts are not provided in the available metadata.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Satellite retrieval from the AIRS and AMSU instruments aboard the EOS Aqua polar-orbiting platform.

Freshness

2026-04-10 17:45:00.595916 (Note: This future date from one source conflicts with a 2012 date from another.)

Geography

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