The semianalytical cloud retrieval algorithm for SCIAMACHY II. The application to MERIS and SCIAMACHY data

摘要

The SemiAnalytical CloUd Retrieval Algorithm (SACURA) is appliedto the SCanning Imaging Absorption spectroMeter for AtmosphericCHartographY (SCIAMACHY) data. In particular, we derivesimultaneously cloud optical thickness (COT) and cloud topheight (CTH), using SCIAMACHY measurements in the visible(442 nm, COT) and in the oxygen A-band (755–775 nm, CTH). Someof the results obtained are compared with those derived from theMedium Resolution Imaging Spectrometer (MERIS), which has betterspatial resolution and observes almost the same scene asSCIAMACHY. The same cloud algorithm is applied to both MERIS andSCIAMACHY data. In addition, we perform the vicarious calibrationof SCIAMACHY at the wavelength 442 nm, using MERIS measurements atthe same wavelength. Differences in the retrieved COT for the samecloud field obtained using MERIS and SCIAMACHY measurements arediscussed.