Characteristics of Precipitation Change over the Qinghai-Xizang Plateau from 1961 to 2099 based on CMIP6 Models

Abstract

The Qinghai-Xizang Plateau （QXP） is a sensitive area of the land-sea-air interaction， its precipitation changes play a crucial role in the local and Asian water cycle.However， there is not enough knowledge of the Spatio-temporal variability of precipitation changes over the QXP during the 21st century so far.In this study， based on 25 Earth-Climate system models’ simulation data from the Coupled Model Intercomparison Project Phase 6 （CMIP6）， the ability of 25 CMIP6 models to simulate precipitation changes was analyzed and compared with the precipitation data measured at 76 meteorological stations over the QXP during the period of 1961 -2014.It was found that the multi-model ensemble mean showed a better skill than most of single models in simulating precipitation over the QXP.Therefore， we analyzed the Spatio-temporal characteristics of precipitation changes through the multi-model ensemble mean under SSP1-2.6， SSP2-4.5， SSP3-7.0 and SSP5-8.5 scenario over the QXP during the period of 2015 -2099.It was found that the annual precipitation will demonstrate a significant increase tendency with obvious inter-decadal fluctuations in the future over the QXP.Spatially， the precipitation changes showed a feature of increasing from northwest to southeast， and the increase of precipitation is more significant for the high emission scenario.Compared with the baseline period of 1995 -2014， the increase in precipitation showed a characteristic of positive north and negative south in the near-term （2020 -2039）， and the largest increase areas are distributed in the central and western of the Northern Tibetan Plateau and Kunlun Mountains.The opposite characteristics of precipitation change will disappear in the mid-term （2040 -2059） and the long-term （2080 -2099）， and the increasing trend was showed in the north and south.The largest increase areas of precipitation are distributed in the southern region， and the smallest increase areas of precipitation are distributed in the Qaidam Basin and the Pamirs.The increase of precipitation will be more significant and the spatial difference will be greater under the high emission scenario in the mid-term and the long-term.Compared with the baseline period of 1995 -2014， the annual precipitation of the Tibetan Plateau will increase by about 65 mm， 94 mm， 146 mm， and 180 mm under the SSP1-2.6， SSP2-4.5， SSP3-7.0 and SSP5-8.5 scenario at the end of 21st century， respectively.At the same time， the 400 mm and 800 mm isohyet will move northward.It indicates that the arid areas will reduce and the Wetness areas will expand over the QXP， and the area of Wetness areas will expand significantly under the high emission scenario.

Keywords

• qinghai-xizang plateau（qxp）
• precipitation
• cmip6
• ssp scenario
• spatio-temporal variation