Synergistic use of AIRS and MODIS radiance measurements for atmospheric profiling

Retrieval of atmospheric profiles from combined radiance measurements of the Atmospheric InfraRed Sounder (AIRS) and the MODerate resolution Imaging Spectroradiometer (MODIS) onboard the NASA Aqua satellite is investigated. The collocated operational MODIS cloud mask product and the clear‐sky InfraRed (IR) radiance measurements are used to characterize the AIRS sub‐pixel cloud fraction and improve the atmospheric sounding and the surface parameters at the AIRS single field‐of‐view (SFOV) resolution. The synergistic algorithm employs an eigenvector based regression with additional information from MODIS measurements. The regression coefficients are derived from a global dataset containing atmospheric temperature, moisture, and ozone profiles. Evaluation of the retrieved profiles is performed by comparisons between AIRS soundings, European Centre for Medium‐Range Weather Forecasts (ECMWF) analysis fields and radiosonde observations from the Cloud And Radiation Testbed (CART) in Oklahoma. Spectral radiance calculations from the sounding retrievals agree with the observations from AIRS adjacent clear neighbor footprint quite well. These comparisons demonstrate the potential advantage of synergistic use of high‐spectral sounder and high‐spatial imager over either system alone.