VALIDATION OF CARBON MONOXIDE VERTICAL COLUMN DENSITIES RETRIEVED FROM SCIAMACHY INFRARED NADIR OBSERVATIONS

摘要

This validation study examines the accuracy of carbonmonoxide (CO) total columns derived from nadirmeasurements of the SCanning Imaging AbsorptionspectroMeter for Atmospheric CHartographY (SCIAMACHY).Therefore, an intercomparison of the COcolumns estimated from SCIAMACHY measurementswith coincidented and colocated retrievals provided byseveral ground-based (g-b) stations affiliated to the Networkfor the Detection of Atmospheric CompositionChange (NDACC) and the Total Carbon Column ObservingNetwork (TCCON) had been performed. The studydemonstrated that the SCIAMACHY CO total columnvalidation results depend on many aspects. The resultsindicate particularly the importance of appropriate postprocessingof the BIRRA retrievals (esp. filtering). Itshows that the CO product is sensitive to settings in retrievalalgorithm. Furthermore, the analysis gives evidenceof a degrading channel 8 detector in later years. Inconclusion, for most cases monthly mean SCIAMACHYCO total columns agree within the standard deviationwhen compared to g-b measurements.