Retrieving atmospheric CO2 profile over Southern Ocean from underway and AIRS data

Basing on the shipboard measurements obtained during the 24th CHINARE campaigns and radiance of AIRS, we get the initial value from the statistical regression according to latitude-based classification. The atmospheric CO2 vertical profile was computed by line-by-line radiative transfer model using the temperature from AMSU and radiance from the thirteen selected AIRS channels. The results were compared with measurements from WDCGG, which show the accuracy change with latitude and relative errors are 0.31%, 1.17% and 2.63% from low to high latitude respectively. The results were compared with CO2/AIRS from NASA, which show the relative errors are 1.11% and 1.07% respectively.