Discussion of the“warming and wetting”trend and its future variation in the drylands of Northwest China under global warming  

作　　者：Fahu CHEN Tingting XIE Yujie YANG Shengqian CHEN Feng CHEN Wei HUANG Jie CHEN 

机构地区：[1]Group of Alpine Paleoecology and Human Adaptation(ALPHA),State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources(TPESER),Institute of Tibetan Plateau Research(ITPCAS),Chinese Academy of Sciences(CAS),Beijing 100101,China [2]Key Laboratory of Western China’s Environmental Systems(Ministry of Education),College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China [3]Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security,Institute of International Rivers and Eco-Security,Yunnan University,Kunming 650500,China [4]Key Laboratory of Tree-Ring Physical and Chemical Research of the Chinese Meteorological Administration,Xinjiang Laboratory of Tree-Ring Ecology,Institute of Desert Meteorology,Chinese Meteorological Administration,Urumqi 830002,China [5]College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China

出　　处：《Science China Earth Sciences》2023年第6期1241-1257,共17页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41988101&42101149);the National Key Research and Development Program of China(Grant No.2018YFA0606404).

摘　　要：Since Shi et al.proposed that the climate in the drylands of Northwest China experienced a significant transition from a“warming and drying”trend to a“warming and wetting”trend in the 1980s,researchers have conducted numerous studies on the variations in precipitation and humidity in the region and even in arid Central Asia.In particular,the process of the“warming and wetting”trend by using obtained measurement data received much attention.However,there remain uncertainties about whether the“warming and wetting”trend has paused and what its future variations may be.In this study,we examined the spatiotemporal variations in temperature,precipitation,the aridity index(AI),vegetation,and runoff during 1950-2019.The results showed that the climate in the drylands of Northwest China and the northern Tibetan Plateau is persistently warming and wetting since the 1980s,with an acceleration since the 1990s.The precipitation/humidity variations in North China,which are mainly influenced by summer monsoon,are generally opposite to those in the drylands of Northwest China.This reverse change is mainly controlled by an anomalous anticyclone over Mongolia,which leads to an anomalous easterly wind,reduced water vapor output,and increased precipitation in the drylands of Northwest China.While it also causes an anomalous descending motion,increased water vapor divergence,and decreased precipitation in North China.Precipitation is the primary controlling factor of humidity,which ultimately forms the spatiotemporal pattern of the“westerlies-dominated climatic regime”of antiphase precipitation/humidity variations between the drylands of Northwest China and monsoonal region of North China.The primary reasons behind the debate of the“warming and wetting”trend in Northwest China were due to the use of different time series lengths,regional ranges,and humidity indices in previous analyses.Since the EC-Earth3 has a good performance for simulating precipitation and humidity in Northwest and North China.By using its

关 键 词：The drylands of Northwest China “Warming and wetting”transition Sustained“warming and wetting” Westerliesdominated climatic regime Moderate warming 

分 类 号：P46[天文地球—大气科学及气象学]