环球遥相关对东南亚低纬高原冬季降水年际变化影响的研究  

Influence of Circumglobal Teleconnection on the Interannual Variability of Winter Precipitation over the Southeast Asian Low-Latitude Highlands

作　　者：徐铭阳 曹杰[1] XU Mingyang;CAO Jie(Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion,Y unnan University,Kunming 650500,Yunnan,China)

机构地区：[1]云南省大湄公河次区域气象灾害与气候资源重点实验室,云南大学,云南昆明650500

出　　处：《高原气象》2024年第4期1011-1025,共15页Plateau Meteorology

基　　金：国家自然科学基金项目(42030603);云南大学研究生科研创新项目(KC-22221251)。

摘　　要：根据欧洲中期天气预报中心(ECMWF)提供的ERA5再分析资料、美国地质调查局与加州大学共同开发的气候灾害组融合站点(CHIRPS)月平均降水资料,以及全球降水气候项目提供的全球降水气候数据集(GPCP)月平均降水资料,利用统计诊断方法研究了冬季环球遥相关(circumglobal teleconnection,CGT)对东南亚低纬高原地区同期降水年际变化的影响。相关分析的结果表明,CGT呈现方差贡献大致相当的两个主要模态,垂直方向上呈现相当正压结构,水平方向上的四个异常中心分别为位于地中海附近和印度半岛附近的负异常中心,以及位于阿拉伯半岛附近和东南亚低纬高原附近的正异常中心。CGT第一模态与东南亚低纬高原冬季降水呈现显著的正相关关系,在年际时间尺度上,当冬季CGT处于正位相时,欧洲西部、阿拉伯半岛西北部、阿拉伯海和东南亚低纬高原分别为异常“反气旋、气旋、反气旋、气旋”控制。异常气旋东侧的西南风将增加孟加拉湾和中国南海进入东南亚低纬高原的水汽输送,并在东南亚低纬高原地区辐合上升,最终促使东南亚低纬高原地区冬季降水偏多;反之,当冬季CGT处于负位相时,欧洲西部、阿拉伯半岛西北部、阿拉伯海和东南亚低纬高原为异常“气旋、反气旋、气旋、反气旋”控制。异常反气旋东侧的东北风减弱了由孟加拉湾和中国南海进入东南亚低纬高原的水汽,加之东南亚低纬高原处于异常辐散下沉区,最终导致东南亚低纬高原地区冬季降水偏少。东南亚低纬高原12月、1月和2月的降水与同期CGT之间也呈现显著的正相关关系,联系两者的关键物理过程与整个冬季的一致。典型个例分析的结果进一步验证了相关分析所揭示的环球遥相关影响东南亚低纬高原冬季降水年际变化的关键物理过程。The influence of winter circumglobal teleconnection(CGT)on the interannual variability of winter precipitation in the Southeast Asian low-latitude highlands were statistically analyzed using ERA5 reanalysis data from the European Centre for Medium-Range Weather Forecasts(ECMWF),monthly mean precipitation data from the Climate Hazards Group Infrared Precipitation with Station data(CHIRPS)developed by the United States Geological Survey and the University of California and the monthly mean precipitation data of the Global Precipitation Climatology Project(GPCP)provided by the Global Precipitation Climatology Center.Results of correlation analysis show that the CGT presents two main patterns with approximately the same variance contribution rate.On the vertical direction,the CGT shows an equivalent barotropic structure with four anomalous centers.During the CGT positive phase,the negative anomalous centers are located near the Mediterranean Sea and the Indian Peninsula,and the positive anomalous centers near the Arabian Peninsula and Southeast Asian low-latitude highlands.The first mode of CGT(CGT1)significantly correlates with winter precipitation over the Southeast Asian low-latitude highlands on the interannual time scale.When the CGT1 is in the positive phase in winter,the anomalous"anticyclone,cyclone,anticyclone,cyclone"control the Western Europe,the northwestern Arabian Peninsula,the Arabian Sea and Southeast Asian low-latitude highlands,respectively.The anomalous southwesterly wind on the east side of the anomalous cyclone will increase the water vapor from the Bay of Bengal and the South China Sea to the Southeast Asian low-latitude highlands.The more water vapor converged and condensed in Southeast Asian low-latitude highlands finally results in heavier winter precipitation over the Southeast Asian low-latitude highlands.On the contrary,when the CGT1 is in the negative phase in winter,the Western Europe,the northwestern Arabian Peninsula,the Arabian Sea and the Southeast Asian low-latitude highlands are co

关 键 词：环球遥相关 东南亚低纬高原 冬季降水 年际变化 

分 类 号：P461[天文地球—大气科学及气象学]