塔里木河流域夏季降水年际和年代变化的环流异常  

Circulation Anomalies of Interannual and Interdecadal Changes in Summer Precipitation over the Tarim River Basin

作　　者：李红军[1,2] 姚梦莹 李淑娟 陈平[1,2] 陈静 LI Hongjun;YAO Mengying;LI Shujuan;CHEN Ping;CHEN Jing(Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,China;Center for Central Asian Atmosphere Science Research,Urumqi 830002,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]中亚大气科学研究中心,新疆乌鲁木齐830002

出　　处：《沙漠与绿洲气象》2024年第3期1-8,共8页Desert and Oasis Meteorology

基　　金：新疆重点自然科学基金(2022D01D86);中国气象局项目(JCZX2023015);科研院所科研业务费(IDM202202)。

摘　　要：基于1961-2020年夏季(6-8月)NCAR/NCEP再分析资料和塔里木河流域38个气象站降水资料,使用5 a滑动平均分离出该流域夏季降水年代际和年际变化,选出年际变化典型的干年和湿年与年代际变化的干期(1963-1986年)和湿期(1989-2018年),分析与这两种时间尺度变化相关联的大气环流异常。结果表明:影响年代际变化的大气环流异常主要是大西洋和欧亚大陆的对流层位势高度场从西北至东南交替出现反气旋和气旋距平环流。在湿期,分别在蒙古国和中亚的反气旋和气旋距平环流加强,塔里木河流域东部和西部分别出现明显的东风和西南风异常,来自西北太平洋和印度洋的水汽增多;在干期则相反。影响年际变化的大气环流异常主要是:在湿年,塔里木河流域之外的西北部和东北部的对流层都为显著的反气旋距平环流,塔里木河流域西部对流层为气旋距平环流,流域东部对流层为反气旋和气旋距平环流影响区;从南北方向向塔里木河流域输送的水汽增多,北风的水汽输送增加较多,南风的水汽输送增加较少,来自北冰洋和印度洋水汽增多;在干年则相反。The interdecadal and interannual changes in summer precipitation in the Tarim River Basin(TRB)were analyzed by using the NCAR/NCEP reanalysis data in summer(June-August)from 1961 to 2020 and precipitation data from 38 meteorological stations.A 5-year running average was employed to distinguish between interdecadal and interannual changes.Typical dry and wet years,as well as dry periods(1963-1986)and wet periods(1989-2018)with interannual variations,were identified.Furthermore,the atmospheric circulation anomalies related to these two time-scale changes were investigated.The analysis reveals distinct differences in the changes between interdecadal and interannual patterns of precipitation.Moreover,the atmospheric circulations influencing these changes also exhibit dissimilarities.The interdecadal variations in atmospheric circulation anomalies primarily manifest as alternating anticyclonic and cyclonic anomalies in the tropospheric geopotential height fields of the Atlantic and Eurasia,extending from northwest to southeast.During the wet period,the anticyclone and cyclone intensify in Mongolia and Central Asia,respectively.Noticeable easterly and southwesterly wind anomalies occur in the eastern and western regions of the basin,respectively.Additionally,the increased water vapor mainly originates from the northwest Pacific Ocean and the Indian Ocean.Conversely,during the dry period,the opposite conditions prevail.The primary atmospheric circulation anomalies influencing the interannual variations are as follows:during wet years,significant anticyclonic anomalies occur outside the TRB in the northwest and northeast regions of the troposphere,while cyclonic anomalies dominate in the western part of the TRB.Moreover,the eastern region of the basin experiences an intersection of anticyclonic and cyclonic anomalies.The transport of water vapor from the north and south to the TRB increases,with the north wind water vapor flux anomaly exhibiting greater transport to the basin.Conversely,the south wind water vapor flux an

关 键 词：大气环流异常 降水量 年代际和年际变化 塔里木河流域 

分 类 号：P426.614[天文地球—大气科学及气象学]