Satellite multi-frequency observations of severe convective systems in the Mediterranean

In the present work two convective episodes in the Mediterranean are studied by means of nearly simultaneous Meteosat Visible-Infrared and SSM/I Passive Microwave data. The two datasets are carefully co-located and an estimate of the uncorrected errors is given in order to have a reliable pixel-by-pixel matching in the images, where possible. The aim of this work is to provide detailed observation of such cloud systems on a pure satellite basis. The two severe convective events are investigated by estimating absorbing and scattering cloud layers in terms of conceptual models available for these cloud systems. The use of microwave derived scattering and absorption indicators, coupled with the cloud top Meteosat observations, is able to describe at least qualitatively relevant features of convective clouds, such as the onset of precipitation and the structure of the anvil. Rain areas computed by two (one for Meteosat IR and one for SSM/I) single-threshold rainfall estimation techniques are compared and significant discrepancies are found.