Interannual precipitation variations in the mid-latitude Asia and their association with large-scale atmospheric circulation  

作　　者：HUANG Wei CHEN FaHu FENG Song CHEN JianHui ZHANG XiaoJian 

机构地区：[1]MOE Key Laboratory of West China's Environmental System,Lanzhou University [2]School of Natural Resources,University of Nebraska-Lincoln

出　　处：《Chinese Science Bulletin》2013年第32期3962-3968,共7页

基　　金：supported by the National Basic Research Program of China (2012CB955303);the Program for New Century Excellent Talents in University (NCET-09-0439);the National Natural Science Foundation of China (41021091 and 41130102);the Program of Introducing Talents of Discipline to Universities (B06026);the Fundamental Research Funds for the Central Universities (lzujbky-2012-k45)

摘　　要：This study analyzed the spatial differences of the precipitation variations in the mid-latitude Asia and their possible physical mechanisms during 1960–2009.The annual precipitation showed an opposite variations between the westerlies-dominated arid Central Asia(ACA)and monsoon-dominated North China(NC)during the study period.Given the different contributions of seasonal precipitation to annual total precipitation in ACA and NC,the atmospheric circulation anomalies during the major precipitation seasons(winter in ACA/summer in NC)were analyzed.In winter,negative North Atlantic Oscillation may cause negative height anomalies over the north side and positive anomalies over the south side of the ACA.Together,the enhanced pressure gradient and anomalous westerly wind brings more water vapor to ACA,and leaves less precipitation in NC.In summer,the low-pressure anomalies in Northeast China,along with a weaker summer monsoon and negative height anomalies in Eastern Europe together contribute to reduced(excessive)summer precipitation in NC(ACA).The interactions between ENSO and NAO may result in the opposite precipitation variations between ACA and NC.A significant 2–3-year cycle is identified in ACA,which is linked to the variations of westerly circulation in the middle troposphere.This study analyzed the spatial differences of the precipitation variations in the mid-latitude Asia and their possible physical mechanisms during 1960-2009. The annual precipitation showed an opposite variations between the westerlies-dominated arid Central Asia （ACA） and monsoon-dominated North China （NC） during the study period. Given the different contributions of sea- sonal precipitation to annual total precipitation in ACA and NC, the atmospheric circulation anomalies during the major precipita- tion seasons （winter in ACA/summer in NC） were analyzed. In winter, negative North Atlantic Oscillation may cause negative height anomalies over the north side and positive anomalies over the south side of the ACA. Together, the enhanced pressure gradient and anomalous westerly wind brings more water vapor to ACA, and leaves less precipitation in NC. In summer, the low-pressure anomalies in Northeast China, along with a weaker summer monsoon and negative height anomalies in Eastern Eu- rope together contribute to reduced （excessive） summer precipitation in NC （ACA）. The interactions between ENSO and NAO may result in the opposite precipitation variations between ACA and NC. A significant 2-3-year cycle is identified in ACA, which is linked to the variations of westerly circulation in the middle troposphere.

关 键 词：大气环流异常 降水变化 中纬度地区 大尺度 关联 北卡罗来纳州 高度距平 北大西洋涛动 

分 类 号：P426.614[天文地球—大气科学及气象学]