Statistical distributions of water content and sizes for clouds above Europe

Abstract. The statistics of quantities involved in the synthesis of cloud scenes have been investigated from an original data base. Frequency distributions of ice and water content (IWC), horizontal and vertical sizes (L and H), and top temperatures (T) of clouds above Europe have been derived for nine types of clouds (As, Cb, Ci, Cg, LwCg, OrCg, Cs, Ns, Sc). It appears that the cumulated frequency plots can be well fitted with log-normal or Weibull profiles, and that for IWC and T cloud types can be split into two or three classes according to slopes in logarithmic coordinates. Cross-correlation coefficients between IWC, L, H and T have been also derived. Implications for the physics of the cloud build-up processes are briefly outlined. Critical analysis and comparison of other published results are proposed.

Key words: Meteorology and atmospheric dynamics (climatology)