AIRS/Aqua L3 Monthly CO2 in the free troposphere (AIRS-only) 2.5 degrees x 2 degrees V005 (AIRS3C2M)

The quantity is what results when the true atmospheric CO2 profile is weighted, level-by-level, by the AIRS sensitivity function. The file format is HDF-EOS 2.12 corresponding to HDF4. This AIRS mid-tropospheric CO2 Level 3 Monthly Gridded Retrieval Product contains standard retrieval means, standard deviations and input counts as well as the latitude and longitude arrays giving the centers of the grid boxes.

Each file covers a calendar month. The mean values are simply the arithmetic means of the individual CO2 retrievals which fall within that grid box over the month. The mid-tropospheric CO2 retrievals have been averaged and binned into 2.5 degree longitude x 2 degree latitude grid cells, from -180.0 to +180.0 deg longitude and from -60.0 to +90.0 deg latitude.

For each grid map of 4-byte floating-point mean values there is a corresponding 4-byte floating-point map of standard deviation and a 2-byte integer grid map of counts. The counts map provides the user with the number of points per bin that were included in the mean.