梅雨季西太平洋副热带高压异常主要模态及其对东亚降水的可能影响  

Principal modes of the Western Pacific Subtropical High anomaly and their possible impacts on precipitation in East Asia during Meiyu season

作　　者：钱代丽 管兆勇[1] QIAN Daili;GUAN Zhaoyong(Key Laboratory of Meteorological Disaster,Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/International Joint Laboratory on Climate and Environment Change,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验室南京信息工程大学,南京210044

出　　处：《气象科学》2020年第5期649-660,共12页Journal of the Meteorological Sciences

基　　金：国家重点研发计划项目(2019YFC1510201);国家自然科学基金资助项目(41975073,41905061)。

摘　　要：利用近42 a NCEP/NCAR再分析资料,NOAA(National Oceanic and Atmospheric Administration)海表温度,CPC(Climate Prediction Center)降水以及中国台站降水观测资料等,对6-7月西太平洋副热带高压(Western Pacific Subtropical High,WPSH)变动的主要模态和形成原因,及其对中国梅雨期降水分布的影响进行了探讨。结果表明,WPSH主要异常模态依次为全区一致型(Ⅰ),南北异常型(Ⅱ)、东西异常型(Ⅲ)和中心异常型(Ⅳ)。不同异常型的出现受中纬度上游西风带准定常扰动和低纬扰动的不同影响,而后者又与对流层低层大气对不同海温异常型热力强迫响应有关。来自热带中东太平洋的海平面气温异常(Sea Surface Temperature Anomaly,SSTA)信号有利于副热带高压出现第Ⅰ、Ⅱ型异常;第Ⅲ、Ⅳ型异常则分别受海洋性大陆或西北太平洋下垫面热力影响。长江-黄河-日本沿线以及江南和东北地区降水与副热带高压第Ⅰ、Ⅲ、Ⅳ型异常密切联系。By using NCEP/NCAR reanalysis,NOAA Sea Surface Temperature(SST),merged precipitation from Climate Precipitation Center(CPC),and precipitation data from CMA,in recent 42 years,the main modes of variations of the Western Pacific Subtropical High(WPSH)from June to July and their possible impacts on the precipitation during the Meiyu period were investigated.Results show that the four leading modes are a zonally extended triple pattern(Ⅰ),a north-south dipole pattern(Ⅱ),an east-west dipole pattern(Ⅲ),and a central pattern(Ⅳ).Different patterns are affected by different anomalous circulation patterns in westerlies in the middle and lower latitudes.The anomalous circulation patterns in lower latitudes are related to the atmospheric response to the abnormal thermal forcing of SST Anomalies(SSTA).The SSTAs in the equatorial central East Pacific are favorable for WPSH to behave in a way with patterns of typeⅠandⅡ.If the remote forcing in earlier period of time is not so strong,the WPSH will be affected by the thermal forcing of the underlying surface over the Marine Continent or the Northwest Pacific,which is conducive to the occurrences of type III and type IV patterns.The typeⅠ,ⅢandⅣanomalies are found to have possibly strong impacts on the precipitation in regions including Yangtze River,Yellow River,South China,Northeast China,and Japan.These results are helpful for better understanding the mechanisms of WPSH variations and finding clues to climate predictions.

关 键 词：西太平洋副热带高压 主模态 梅雨 热力强迫 遥相关 

分 类 号：P434[天文地球—大气科学及气象学]