前期西太平洋暖池热含量异常对中国东北地区夏季降水的影响

摘要

利用日本气象厅历史海温资料、NCEP/NCAR再分析资料、哈得来环流中心海表温度资料和降水资料,研究了1951-2010年中国东北地区夏季降水与前期西太平洋暖池(简称暖池)热含量异常的关系,并对可能影响途径进行了探讨.结果表明,中国东北地区夏季降水与前期暖池热含量有密切的负相关,前期10-11月暖池关键区(15.5°-20.5°N,125.5°—135.5°E)0-200m热含量高(低)是预报中国东北地区夏季旱(涝)的一个很好的指标.前期暖池热含量异常激发的夏季东亚-太平洋型遥相关(EAP)和中纬度高层沿亚洲西风急流东传波列的存在,可能是影响中国东北地区夏季降水的主要原因.当前期10-11月暖池区热含量为负异常时,菲律宾反气旋异常持续存在,夏季东亚-太平洋遥相关型出现,导致西太平洋副热带高压西伸加强,中国东北地区局地异常低气压和鄂霍次克海阻塞高压形成.同时,高空存在沿西风急流传播的遥相关波列,使得中国东北地区局地异常低气压和西太平洋副热带高压在日本附近增强,有利于中国东北地区夏季降水偏多；反之亦然.%The relationship between the summer rainfall over Northeast China and the previous heat content anomaly in the western Pacific warm pool (WPWP) and the way how heat content anomaly probably affects the precipitation in Northeast China has been investigated by using the historical ocean temperature analysis data provided by Japan Meteorological Agency,the NCEP/NCAR reanalysis data,the Hadley Centre sea surface temperature (SST) dataset and rainfall data.The results show that there is a close negative correlationship between the summer rainfall over Northeast China and the previous heat content anomaly in the WPWP,through which a good predictor,i.e.the 0-200 m heat content averaged over October to November in the key area (15.5°-20.5°N,125.5°-135.5°E) of the WPWP,is found for the precipitation of the following summer in Northeast China.The East Asia-Pacific (EAP) teleconnection stimulated by the previous heat content anomaly of the WPWP,and the wave train propagating eastward along the Asian westerly jet stream in the upper level of the mid-latitude region may be the main reason that influences the summer rainfall over Northeast China.When the 0-200 m heat content anomaly averaged over the previous October to November in the key area is negative,the anomalous Philippine Sea anticyclone persists and EAP teleconnection appears during the summertime,leading to the westward extending and enhancing of the western Pacific subtropical high (WPSH) as well as the formation of the local anomalous cyclone over Northeast China and the Okhotsk blocking high.Meanwhile there exists a teleconnection wave train propagating eastward along the Asian westerly jet stream in the upper troposphere so that the local anomalous cyclone over Northeast China and WPSH near Japan can be enhanced,which is conducive to more rain in Northeast China.Otherwise,the summer rainfall is suppressed.