前期青藏高原积雪与ENSO对南海夏季风强度的协同影响  

Synergistic effects of the Tibetan Plateau snow and ENSO as preceding signals on the intensity of South China Sea summer monsoon

作　　者：邓琪 赵平[2] 温之平 王慧美 王迎春[3] DENG Qi;ZHAO Ping;WEN Zhiping;WANG Huimei;WANG Yingchun(Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences,Fudan University,Shanghai 200438,China;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;Beijing Meteorological Administration,Beijing 100089,China)

机构地区：[1]复旦大学大气与海洋科学系/大气科学研究院,上海200438 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]北京市气象局,北京100089

出　　处：《气象学报》2022年第4期491-502,共12页Acta Meteorologica Sinica

基　　金：第二次青藏高原综合科学考察研究(2019QZKK020803);丝路环境先导专项(XDA2010030807)。

摘　　要：基于1980—2018年罗格斯大学全球积雪实验室积雪面积、英国气象局哈得来中心海温、欧洲中期天气预报中心(ECMWF)第5代再分析(ERA-5)土壤湿度、美国国家环境预报中心和美国国家大气研究中心(NCEP/NCAR)再分析、美国国家海洋大气管理局(NOAA)气候预测中心降水(CMAP)和全球降水气候计划降水(GPCP)等数据,采用相关、合成和回归等分析方法,分析了前期青藏高原积雪和厄尔尼诺-南方涛动(ENSO)年际尺度变化对南海夏季风强度及降水的协同影响。结果表明:在年际尺度上,青藏高原积雪、ENSO与南海夏季风变率有密切关系,当青藏高原春季积雪西部偏多且东部偏少时,夏季高原西部对流层温度偏低,在高原上空产生异常下沉气流并向外辐散,引起中国南海地区对流层中低层为异常下沉气流。另外,赤道中东太平洋海温异常偏高则会使夏季印度洋海温异常偏高,对流层温度偏高,在西北太平洋产生东北风异常,加强西北太平洋和中国南海上空的反气旋性环流异常。在青藏高原积雪和ENSO共同影响下,夏季850 hPa中国南海上空反气旋异常进一步加强,南海夏季风强度减弱,降水减少。Based on the Rutgers University Global Snow Lab snow cover,the British Meteorological Office Hadley Center sea surface temperature(SST),soil moisture of the European Centre for Medium-Range Weather Forecasts Fifth Generation Reanalysis(ERA-5),the National Centers for Environmental Prediction National Center for Atmospheric Research reanalysis,the National Oceanic and Atmospheric Administration(NOAA)Climate Prediction Center Merged analysis of Precipitation(CMAP)and the Global Precipitation Climatology Project(GPCP)precipitation,effects of the Tibetan Plateau(TP)snow and El Niño-Southern Oscillation(ENSO)as preceding signals on the South China Sea(SCS)summer monsoon and precipitation are analyzed using methods of correlation analysis,composite analysis and regression analysis.Results indicate that the SCS summer monsoon is associated with both the TP snow and ENSO on the interannual scale.When the TP snow is higher in the west and lower in the east in spring,the tropospheric temperature in the west of the TP is abnormally low in the subsequent summer,which generates downdrafts over the plateau that flow outward.Accordingly,there are also descending airflows over the South China Sea in the lower and middle troposphere.In addition,anomalously high SSTs in the east-central equatorial Pacific may cause positive SST and tropospheric temperature anomalies in the Indian Ocean with northeasterly wind anomalies over the Northwest Pacific Ocean,which further strengthens the anticyclonic circulation anomaly over the South China Sea.When the TP snow and ENSO are synergistic,their influences on the SCS summer monsoon are stronger.Their joint effect further strengthens the lower-tropospheric anticyclonic anomaly over the South China Sea in summer,weakens the SCS summer monsoon and decreases precipitation in the South China Sea.

关 键 词：南海夏季风 青藏高原积雪 ENSO 协同影响 

分 类 号：P466[天文地球—大气科学及气象学]