新疆夏季降水主模态年代际变化及影响因子分析  

Interdecadal variations and influencing factors in the leading modes of summerprecipitation in Xinjiang

作　　者：刘精 郑育琳 刘艳 李晗薇 LIU Jing;ZHENG Yulin;LIU Yan;LI Hanwei(Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,Xinjiang,China;Xinjiang Climate Center,Urumqi 830002,Xinjiang,China;Xinjiang Meteorological Observatory,Urumqi 830002,Xinjiang,China;Xinjiang Branch China Meteorological Administration Training Centre,Urumqi 830013,Xinjiang,China)

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [2]新疆维吾尔自治区气候中心,新疆乌鲁木齐830002 [3]新疆维吾尔自治区气象台,新疆乌鲁木齐830002 [4]中国气象局气象干部培训学院新疆分院,新疆乌鲁木齐830013

出　　处：《干旱区研究》2025年第4期577-588,共12页Arid Zone Research

基　　金：中央级公益性科研院所基本科研业务费专项资金项目(IDM2020008);自治区重点研发计划项目课题(2023B02044-1);新疆气象局科学研究项目(YD2024031)。

摘　　要：为探讨新疆夏季降水主模态形成机制及潜在外强迫影响,本文采用1979—2023年新疆89个站降水资料及滑动EOF方法获取降水主模态演变特征,并围绕主模态及其环流配置和相关海温积雪变化进行对比分析。结果表明:新疆夏季降水主模态在2005年前后由全区一致型转变为南疆西部型。全区一致型降水偏多(偏少)分布与乌山阻塞强盛(减弱)、中亚低涡活跃(衰减)、孟加拉湾反气旋偏强(偏弱)以及东亚-太平洋遥相关(EAP)正(负)位相密切相关,高、中、低纬系统异常分布导致来自北冰洋、西北太平洋、孟加拉湾以及里咸海等地的4条水汽输送带增强(减弱),环流异常受到赤道中东太平洋海温、热带印度洋海盆一致型(Indian Ocean Basin-Wide,IOBW)海温及北大西洋三极型(North Atlantic Tripole,NAT)海温异常的影响。南疆西部型降水偏多(偏少)主要受里海至贝湖的反气旋-气旋(气旋-反气旋)径向偶极波列以及塔什干低涡增强(减弱)影响,其与前冬东欧-西西伯利亚积雪东多西少(东少西多)偶极异常显著相关。关键区积雪异常可通过“积雪-土壤湿度-大气反馈”过程促使西西伯利亚至贝湖的纬向偶极波列及东欧至伊朗高原的经向三极波列形成,进而调整新疆北部东西风辐合辐散异常及塔什干低涡强度变化,建立影响南疆西部型降水分布的物理途径。To investigate the formation mechanisms and potential external forcing impacts of the dominant sum-mer precipitation patterns in Xinjiang,this study analyzed precipitation data from 89 stations spanning 1979 to 2023 using the sliding Empirical Orthogonal Function method.The evolutionary traits of these patterns were ex-plored through a comparative analysis of precipitation patterns,circulation configurations,and correlated varia-tions in sea surface temperature(SST)and snow cover.The results show that the main mode of summer precipita-tion in Xinjiang shifted around 2005 from a region-wide consistent pattern to a western-southern Xinjiang pat-tern.The distribution of regionally consistent high(low)precipitation was closely related to the strong(weak-ened)Ural blocking highs,active(attenuated)Central Asian vortex,strong(weak)Bay of Bengal anticyclone,and the positive(negative)phase of the East Asia-Pacific Remote Correlation(EAP).The abnormal circulation patterns at high,middle,and low latitudes led to the strengthening(weakening)of four key water vapor conveyor belts originating from the Arctic Ocean,the Northwest Pacific Ocean,the Bay of Bengal,and the Aral Sea.The SST anomalies in the equatorial Middle Eastern Pacific Ocean,the tropical Indian Ocean Basin-Wide,and the North Atlantic Triple influenced the circulation anomalies.The high(low)precipitation of the western-southern Xinjiang pattern was mainly influenced by the anticyclone-cyclone(cyclone-anticyclone)radial dipole wave train from the Caspian Sea to Lake Baikal as well as the strengthening(weakening)of the Tashkent low vortex.The pattern correlated significantly with the dipole anomaly of more east than west(less east than west)of the previ-ous winter’s snow cover in Eastern Europe and Western Siberia.The snow cover anomalies in key areas can be induced by the“snow cover,soil moisture,and atmosphere feedback”process forming a zonal dipole wave train from West Siberia to Lake Baikal and a meridional triple wave train from Eastern Europe to the Ira

关 键 词：夏季 降水主模态 年代际变化 大气环流 新疆 

分 类 号：P426.6[天文地球—大气科学及气象学]