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投稿时间：2015-01-08 修订日期：2015-11-02
投稿时间：2015-01-08 修订日期：2015-11-02
中文摘要: 通过分析处于厄尔尼诺事件发展阶段的我国东部汛期(6—8月)降水异常与海温的关系，指出热带西太平洋海温异常对厄尔尼诺发展阶段汛期降水的异常可能起到重要作用。尽管已有研究显示，处于厄尔尼诺事件发展阶段的夏季容易出现长江以南少雨的分布特征，但本文利用最新资料(1951—2014年)对于所有处于厄尔尼诺发展阶段的夏季降水的分析显示，降水与ENSO指标（Ni〖AKn~D〗o3和Ni〖AKn~D〗o3.4指数）的关系并不显著，却与热带西太平洋海温之间存在显著的相关。同样处于厄尔尼诺发展阶段，降水可能出现截然不同的异常特征，当热带西太平洋海温偏冷时，夏季降水容易出现以长江为界“南少北多”的分布特征，而当热带西太平洋海温偏暖时，降水则容易出现以长江为界“南多北少”的分布特征。分析还指出，当热带西太平洋海温冷、暖不同时，热带（太平洋至印度洋）海温的分布会呈现出不同的特征，从而对热带大气及东亚副热带大气产生不同的影响，最终导致我国东部降水出现不同的异常分布。对于刚刚过去的2014年夏季，热带西太平洋海温异常偏暖可能是导致降水异常分布的原因之一。2014年夏季处于厄尔尼诺事件的发展阶段，同时热带西太平洋海温是1951年以来历次厄尔尼诺发展年夏季之中的最高值，而相应于热带西太平洋偏暖的特征，降水呈现出明显的“南多北少”的异常分布。夏季降水与海温的这种显著关系说明，除了用来定义厄尔尼诺事件的热带中东太平洋海温之外，热带西太平洋海温对于汛期降水的预测也具有重要的指示意义。
中文关键词: 汛期降水， 热带西太平洋， 海温异常， 厄尔尼诺
Abstract:The possible impacts of the tropical western Pacific SSTA on China’s precipitation during the El Ni〖AKn~D〗o developing phases are emphasized in this paper. Analyses of all the 17 summers during the El Ni〖AKn~D〗o developing phases show that precipitation in these summers varies from year to year and does not exhibit a significant relationship with the El Ni〖AKn~D〗o indices (Ni〖AKn~D〗o3 and Ni〖AKn~D〗o3.4 index). However, further analyses reveal that the precipitation is closely related to the tropical western Pacific SSTA during these summers. When the tropical western Pacific is warmer, it is wetter in the south of the Yangtze River and drier in the north, and vice versa. The possible mechanism is also proposed. The different conditions of the western Pacific SST anomalies indicate different distribution features of the SSTA in the tropic Oceans. The different tropical SST patterns can induce different responses to the tropical and the subtropical atmospheric circulation near East Asia. Therefore, the precipitation in the east of China is affected. Besides, the anomalous warm SST in the western Pacific may contribute to the precipitation anomaly in the summer of 2014. The tropical western Pacific in the summer of 2014 is warmer than all the previous 17 summers during the El Ni〖AKn~D〗o developing phases. Such a condition of the tropical western Pacific favors more precipitation in the south of the Yangtze River and less in the north. And the observation of precipitation is also characterized by such a feature. Thus, the tropical western Pacific SSTA may exert an impact on the summer precipitation in 2014.
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基金项目:国家重点基础研究发展计划（973计划）(2013CB430203)、国家科技支撑计划（2015BAC03B04）和公益性行业(气象)科研专项(GYHY201306031)共同资助
| Author Name | Affiliation |
| GU Wei | Laboratory of Climate Studies of CMA, National Climate Centre, Beijing 100081 |
引用文本：
顾薇,2016.夏季热带西太平洋海温对厄尔尼诺发展阶段我国东部汛期降水的影响分析[J].气象,42(5):548-556.
GU Wei,2016.Possible Impact of the Western Tropical Pacific SSTA on Precipitation During the El Ni〖AKn~D〗o Developing Summers in the Eastern Part of China[J].Meteor Mon,42(5):548-556.
顾薇,2016.夏季热带西太平洋海温对厄尔尼诺发展阶段我国东部汛期降水的影响分析[J].气象,42(5):548-556.
GU Wei,2016.Possible Impact of the Western Tropical Pacific SSTA on Precipitation During the El Ni〖AKn~D〗o Developing Summers in the Eastern Part of China[J].Meteor Mon,42(5):548-556.