Retrieval of Co from Sciamachy Onboard Envisat

SCIAMACHY onboard the environmental research satellite ENVISAT is a UV/visible/near-infrared grating spectrometer providing 3 near infrared channels covering wavelengths from 1-1.75μm, 1.94-2.04μm and 2.262.38μm with moderate spectral resolution (0.22-1.5nm) (Bovensmann et al. 1999). Among the absorbers in these regions are the greenhouse gases CO2, CH4, N2O and H2O as well as CO. A modified DOAS algorithm basing on optimal estimation (IMAP-DOAS) has been developed at the University of Heidelberg to account for the peculiarities of the near infrared spectral region (Frankenberg et al. 2004). Especially for the proper retrieval of CO in channel 8 of SCIAMACHY, the calibration of the raw spectra with respect to dark current issues and nonlinearity were analysed in detail and substantially improved. This paper focusses on first results of the CO retrieval where some very interesting sources like biomass burning events can be clearly identified.