No abstract

In the Asian monsoon margin of Northwest China, the impact factors for variations in the aridity and humidity of the summer climate are complex and unclear. In this study, we selected the Alashan Plateau, located in the midlatitude arid zone and the Asian monsoon margin of Northwest China, as the study area. Changes in the aridity index K (a proxy for the arid-humid variations in the summer climate of the Alashan Plateau) were calculated for the period 1960-2010 using meteorological data. Relationships among the aridity index K, changes in the intensity of atmospheric circulations, and local precipitation and evaporation in summer are discussed. The results indicated that the