VALIDATION OF AEROSOL PRODUCTS DERIVED FROM SCIAMACHY

摘要

The present approaches of retrievals of aerosolrnparameters from SCIAMACHY top-of-atmospherern(TOA) rerectance within the nadir mode suu000bersrnfrom the present status of the absolute radiance (processorrnversion 4.02b) calibration, giving a signifcantrnunderestimation of the TOA rerectance. Thus thernaerosol optical thickness (AOT) and the absorbingrnaerosol index (AAI), derived directly from L1B datarngives physically unrealistic results and no regularrnproduct from SCIAMAYHY for validation is currentlyrnavailable.rnAttempts for scientifc products are undertaken usingrncorrection factors for the TOA rerectance by Universityrnof Bremen and KNMI. Comparisons, made withrndiu000berent instruments (MERIS), enables the determinationrnof correction factors for the TOA rerectancernfor selected bands. Tests for the application of suchrncorrection factors brings the AOT and AAI into thernright physical magnitude, showing, that principallyrna determination of aerosol parameters from SCIAMACHYrnTOA rerectance with SCIAMACHY observationsrncan be made. This task requires an urgentrnimprovement of the radiometric key data for the calibrationrnof SCIAMACHY L1b data.