An example of vertical profile of tropospheric aerosol retrieved from radiance imagery measured by the MOS/A and MOS/B spectrometers over the Mediterranean Sea

The aerosol kernel functions relate, through a Fredholm integral equation of the first kind, the variations in radiance measured by satellites to the variations in aerosol extinction profile, and thus allow profile retrieval from radiance measurements by inverting the set of the radiative transfer equations for different spectral intervals. In the past, the kernel functions were evaluated for the red and near infrared spectral regions both outside and inside molecular absorption bands. In this article they are tailored to the spectral characteristics of MOS/A and MOS/B spectrometers flying onboard IRS-P3. Then, the inversion formulas are applied to real data acquired during a clear-sky day over the Mediterranean Sea to retrieve the variations in the aerosol vertical profile (with respect to the first-guess profile). The agreement between MOS data and the radiance values corresponding to the retrieved profile (through a LOWTRAN simulation) is always better than the agreement between MOS data and the radiances corresponding to a first-guess profile (through a LOWTRAN simulation, too). This gives evidence in favor of the developed retrieval scheme based on kernel functions.