Analysis of the spatial Distribution of precipitation and topography with GPM data in the Tibetan Plateau

Abstract

The topography of the Tibetan Plateau (TP) plays an important role in the formation of the Asian monsoon as well as global climate change. In particular, the water vapor transport patters shows redistribution under the influence of high mountains, which profoundly impacts the landscape of the local and surrounding areas. Based on satellite precipitation data of global precipitation measurements from 2015 to 2018, the influence of the topography on the spatial and temporal distributions of the precipitation in the TP was evaluated. The results show that the precipitation distribution is clearly affected by the topography, and decreases from southeast to northwest. Precipitation mainly concentrates in the southern foothills of the Himalayas. In the hinterland of the TP, the gradient distance increases from southeast to northwest, with value changes from 100 mm / 60 km to 100 mm / 150 km. The maximum annual precipitation height in the windward side of the TP (west of Tianshan Mountains, south of Himalayas, and southwest of Hengduan Mountains) is below 2000 m, while in the northern and inner areas, it exceeds 4000 m. The precipitation isoline in the south and northwest of the TP is consistent with the elevation contour. However, in the northeastern and interior areas, the precipitation isoline is consistent with the orientation of the mountain structural belt.