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Trend analysis of MERIS water vapour measurements over cloud free land areas for a period of five years.

Ronny Leinweber(1), Kai Hermann(1) and Juergen Fischer(1)

(1) Fu-Berlin, Carl-Heinrich-Becker-Weg 6-10, 12165 Berlin, Germany


Global water vapour total column amount over cloud free land areas have been retrieved from spectral data provided by the imaging spectrometer MERIS placed on the polar orbiter ENVISAT. A trend analysis over cloud free land surface has been performed on a monthly mean global dataset of water vapor distributed by ACRI-ST. From May 2002 to April 2007 the trend was examined for the global, hemispheric and the Mediterranean area. Assuming a significance of 0.05, the results show that there is a slight and insignificant increase over the Southern Hemisphere and a positive trend of 2.3% or 0.026g/cm² for this period over the northern areas. The global examination reveals a small upwards movement of 1.28% or 0.019 g/cm². A strong increase of 4.9% or 0.056 g/cm² over the Mediterranean area is recovered.


Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry