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Spatial patterns and possible mechanisms of precipitation changes in recent decades over the Tibetan Plateau in the context of intense warming and weakening winds
  • xiaoyu Guo,
  • Lide Tian
xiaoyu Guo
Institute of Tibetan Plateau Research, Chinese Academy of Sciences

Corresponding Author:[email protected]

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Lide Tian
Institute of International Rivers and Eco-security, Yunnan University
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Abstract

The Tibetan Plateau (TP) significantly affects its surroundings and the global climate through thermal and dynamic processes. Precipitation is a key driver of hydrological, meteorological, and ecological processes. In general, the precipitation over the TP displays a wetting trend over the past half century, with large spatial heterogeneity. However, the causes of such spatially variable trends in TP precipitation and the driving forces have not been well quantified. Here we investigate the spatial variations in precipitation trends and their possible mechanisms, using ground-based observations from 132 CMA (China Meteorological Administration) stations (1970–2016) and CMFD (China Meteorological Forcing Dataset) reanalysis data (1980–2016) over the TP. The major findings are: (1) Pronounced spatial patterns of precipitation changes (increasing on the inner TP and decreasing for regions around the TP) are observed in both CMA and CMFD data. (2) Maximum precipitation decreases generally occurred in stations that experienced a southwesterly daily maximum wind speed (Ws). (3) Positive correlations between mean precipitation amount and corresponding temperature (or Ws) are obtained in directions of maximum precipitation increase (decrease), which are further verified by the qualitative and quantitative analysis of the CMFD dataset. Therefore, we suggest that intensified local recycling in a warming and hydrologically unbalanced environment has led to precipitation increases on the central TP, whereas precipitation decreases in areas bordering the TP may be the result of a weakening Indian monsoon.