Space-Time Variability of the Rainfall over Sahel: Observation of a Latitudinal Sharp Transition of the Statistical Properties

摘要: The rain statistics of 0–45° N area including equatorial, Sahelian, and mid-latitude regions, are studied using the probability distributions duration rainy dry events. Long time daily data set from ground measurements satellite observations fields used. This technique highlights a sharp latitudinal transition between equatorial all other regions (Sahel, mid-latitude). distribution 8° S to latitude band shows large-scale organization with slow decreasing (power law decrease) for space size observation is in agreement scaling, or macro turbulent, behavior fields. For Sahelian our clearly not this behavior. They show that largest systems have limited (well described exponential distribution). these non-equatorial it possible define local characteristic horizontal large These characteristics scales observed mesoscale convective could be sensible indicator detection trend properties due anthropogenic influence.