Rainfall Distribution over Central and Southern Israel Induced by Large-Scale Moisture Flux

Abstract

A map of annual rainfall in Israel was obtained from the real-time calculation of the net condensation in large-scale moisture transport through the eastern Mediterranean, sea surface evaporation, and orographic condensation above the Judean mountain range. The averaged rainfall efficiency of condensation over the rainy season is assumed to be a function of the vertically and time-averaged temperature. The calculated rainfall map correlates well with statistical annual rainfall distribution, correlation coefficient 0.9, and allows the effect of the three sources of precipitation mentioned above to be estimated. The condensation within large-scale moisture transport, the main source of precipitation in the Israel region, yields approximately two-thirds of the bulk rainfall in the Mediterranean Sea shore region. The rest results from the contribution of the sea surface evaporation. Orographic condensation starts near the Mediterranean Sea shore and increases in the direction of the Judean mountains, where its contribution to rainfall is approximately equal to the contribution of the condensation within the large-scale moisture flux.