Desert climate and its dynamics

Abstract

Basic characteristics of desert climate are discussed in relation to aridity indices based on water balance and energy balance consideration. The dynamical aspects of the underlying causes in terms of tropical Hadley cell, orographically forced subsidence and large scale ocean-atmosphere interactions are elaborated. Climatological aspects of the Thar desert (Rajasthan) in India and a review of the present and past climates of the region are presented. Interannual fluctuations of arid conditions are discussed in terms of several parameters. Local and regional dynamical aspects of the desert climate as revealed by recent field experiments are discussed. Anthropogenic causes of desertification are discussed in terms of the biogeophysical feedback processes such as albedo, soil moisture and roughness length. Recent work of several workers, employing general circulation modelling experiments to study the sensitivity of land surface processes to desert climate are briefly reviewed.