[摘要] A first validation of water vapour total column amounts derived frommeasurements of the SCanning Imaging Absorption spectroMeter forAtmospheric CHartographY (SCIAMACHY) in the visible spectral region has beenperformed.For this purpose, SCIAMACHY water vapour data have been determined for the year2003 using an extended version of the Differential Optical AbsorptionSpectroscopy (DOAS) method, called Air Mass Corrected (AMC-DOAS).The SCIAMACHY results are compared with corresponding water vapour measurementsby the Special Sensor Microwave Imager (SSM/I) and with model data from theEuropean Centre for Medium-Range Weather Forecasts (ECMWF).
In confirmation of previous results it could be shown that SCIAMACHY derivedwater vapour columns are typically slightly lower than both SSM/I and ECMWFdata, especially over ocean areas.However, these deviations are much smaller than the observed scatter of thedata which is caused by the different temporal and spatial sampling andresolution of the data sets.For example, the overall difference with ECMWF data is only-0.05 g/cm2 whereas the typical scatter is in the order of0.5 g/cm2.Both values show almost no variation over the year.In addition, first monthly means of SCIAMACHY water vapour data have beencomputed.The quality of these monthly means is currently limited by theavailability of calibrated SCIAMACHY spectra.Nevertheless, first comparisons with ECMWF data show that SCIAMACHY (andsimilar instruments) are able to provide a new independent global water vapourdata set.
