The Teleconnection between Rainfall over the Northeastern Slope of the Tibetan Plateau and Downstream Regions:Insights from 20 Years of Heavy Rainfall Events  

作　　者：Wei SUN Rucong YU Jian LI Zewen LI 

机构地区：[1]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China [2]Institute of Tibetan Plateau Meteorology,China Meteorological Administration,Chengdu 610072,China [3]Department of Atmospheric Science,Yunnan University,Kunming 650091,China [4]Inner Mongolia Autonomous Region Mete-orological Service Center,Hohhot 010051,China

出　　处：《Advances in Atmospheric Sciences》2025年第2期327-341,共15页大气科学进展(英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant No.U2142204 and 42475013);the Beijing Nova Program(Z211100002121100);the National Key Research and Development Program of China(2023YFC3007504);the Science&Technology Development Fund of Chinese Academy of Meteorological Sciences(CAMS)(2022KJ007)。

摘　　要：The connection between rainfall over topographic regions and their downstream areas represents a phenomenon of great concern in atmospheric research.Focusing on the rainfall events of the past two decades,we analyzed the impact of rainfall over the Northeastern Slope of the Tibetan Plateau(NSTP)on rainfall in downstream areas.We discovered that rainfall followed two propagation routes,guided by two modes related to the three-dimensional circulation structure.In the first mode,dominated by cold(warm)anomalies along the west(east)direction,rainfall over the NSTP was concentrated between an upstream cyclonic and a downstream anti-cyclonic anomalous circulation(an upstream trough and a downstream ridge).This pattern was accompanied by upper-level divergence,low-level convergence,a deep moist layer,and a vertical updraft.As a consequence of the eastward movement of the trough-ridge system associated with the coldwarm anomalies,the rainfall over the NSTP moved eastward along 37°-40°N,reaching North China after about 36 h.In the second mode,the circulation structure was also dominated by cold-warm anomalies but rotated clockwise,introducing cold anomalies to the northeast and warm anomalies to the east of the plateau.Following the southeastward movement of the circulation structure,rainfall concentrated upstream of the anti-cyclonic circulation around the warm center before moving southeastward to the Sichuan Basin along the eastern edge of the plateau after 30-36 h.The findings of this study could broaden the understanding of rainfall-related teleconnection between two distant regions and offer helpful guidance for identifying early signals of rainfall disasters over the Chinese mainland.

关 键 词：TELECONNECTION rainfall propagation three-dimensional circulation structure upper-tropospheric temperature anomaly 

分 类 号：P426.6[天文地球—大气科学及气象学]