Monthly Mid-Tropospheric Carbon Dioxide Grids from AIRS/Aqua Satellite

Atmospheric Infrared Sounder (AIRS) mid-tropospheric carbon dioxide retrievals, gridded monthly at 2.5° longitude by 2° latitude resolution. The product contains mean CO2 mole fractions, standard deviations, and data counts for each grid cell, produced by NASA's Goddard Earth Sciences Data and Information Services Center (GES DISC). Data collection occurred via the AIRS instrument aboard the Aqua satellite, with the last update recorded in February 2017.

Use Cases

• Analyze spatial patterns of mid-tropospheric CO2 mole fraction using the gridded mean values across the -60° to +90° latitude range.
• Assess retrieval uncertainty for specific grid cells by examining the corresponding standard deviation maps.
• Evaluate data density and sampling reliability for a region by referencing the integer counts map of points per bin.
• Track monthly changes in free troposphere CO2 concentrations over time using the calendar-month time series.
• Validate atmospheric transport models by comparing simulated CO2 fields against the satellite-retrieved mean values weighted by the AIRS sensitivity function.

Strengths

• Global spatial coverage from -180.0 to +180.0 degrees longitude and -60.0 to +90.0 degrees latitude.
• Provides three consistent data layers per grid cell: mean CO2, standard deviation, and input counts.
• Data is gridded at a consistent 2.5° x 2° resolution, facilitating spatial analysis.

Limitations

• Data is not a total column quantity, as retrievals are weighted by an instrument sensitivity function peaking between 6-10 km altitude.
• Temporal coverage is limited to calendar months, with no finer temporal resolution available.
• The dataset's last update was in 2017, limiting analysis of recent CO2 trends.

Provenance

Source

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

Collection Method

Retrievals from the Atmospheric Infrared Sounder (AIRS) grating spectrometer aboard the EOS Aqua satellite, averaged and binned into a global grid.

Time Range

Coverage is for individual calendar months; specific start date unknown.

Freshness

Monthly updates during active collection; last updated 2017-02-28.

Geography

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