Global Atmopheric Water Vapour Variability between 2003 and 2012
Fischer, Jürgen1; Doctor, Nicole2; Diedrich, Hannes2; Lindstrot, Rasmus2; Preusker, Rene2
1Free University Berln, Institute for Space Sciences, GERMANY; 2Free University Berlin, GERMANY

Water vapour is a key climate variable: It is the most important greenhouse gas in the atmosphere, accounting for about 60% of the natural greenhouse effect for clear skies. We present a global time series of total columnar water vapour from observations of MERIS (Medium Resolution Imaging Spectrometer) onboard ENVISAT. The unique dataset, generated within the framework of the ESA GlobVapour project, arebderived from the most accurate satellite measurements available. The resulting daily composites and monthly means of total columnar water vapour are available as global maps on rectangular latitude-longitude grids with a spatial resolution of 0.05°x0.05°. We compare the MERIS based total water vapour contents with results of the ERA-Interim reanalysis data and discuss the differences in both datasets.