摘要:根据气象行业标准（QT/T370-2017）对厄尔尼诺事件不同类型的划分结果以及国家气候中心最新颁布的华南前汛期业务监测标准，利用1961~2016年NCEP/NCAR日、月尺度再分析大气环流资料、海表温度资料（ERSST V4）以及华南261个国家气象观测站逐日降水资料，采用相关、合成等方法分析了不同类型、强度的厄尔尼诺事件特征以及与次年华南前汛期的关系，并探讨其海温和大气环流异常特征。结果表明，厄尔尼诺事件的类型、强度对次年华南前汛期降水的影响存在明显差异。中等及以上强度东部型厄尔尼诺事件次年，华南前汛期开汛早、结束晚，前汛期持续时间长、降水多；弱等级的东部型以及中部型厄尔尼诺事件次年则相反。在厄尔尼诺事件次年华南前汛期，中等及以上强度东部型厄尔尼诺相对弱东部型或中部型厄尔尼诺的大气环流存在明显差异。高层西风急流明显加强，中层北半球极涡加强，东亚大槽强，低层菲律宾以东存在反气旋异常环流，华南存在南北风的交汇和水汽辐合加强，有利于华南前汛期降水偏多。
关键词:厄尔尼诺事件/
类型/
强度/
前汛期降水/
华南
Abstract:Based on the meteorological industry standard(QT/T370-2017)for El Ni?o events of different types and the latest monitoring standard of the first rainy season in South China issued by National Climate Center, using the NCEP/NCAR daily and monthly reanalysis data, NOAA SST data (ERSST V4), and the data collected at 261 meteorological observational stations in South China from 1961 to 2016, the relationship between El Ni?o events of different types and intensity and precipitation in the subsequent first rainy season in South China and the characteristics of the atmospheric circulation and SST are analyzed by correlation and composite analysis methods. The results show that the impacts of El Ni?o events of different types and intensity on the subsequent first rainy season in South China are obviously different. Under the influence of the East Pacific El Ni?o events with medium and higher intensity, the onset date of the first rainy season in South China is earlier than normal while the ending date is later than normal and the duration is longer with higher than normal precipitation. The opposite is true when South China is under the influence of East Pacific El Ni?o events with weak intensity or under the influence of central Pacific El Ni?o events. The atmospheric circulation in the first rainy season in South China under the influence of East Pacific El Ni?o events with medium and higher intensity is obvious different from that under the influence of weak East Pacific El Ni?o events or central Pacific El Ni?o events. In the former condition, the westerly jet in upper levels intensify, the polar vortex in the Northern Hemisphere and the East Asia major deep trough both become stronger than normal, an anomalous anticyclone develops to the east of the Philippines in the middle levels, and moisture convergence occurs in South China where southerly and northerly winds converge.
Key words:El Ni?o events/
Types/
Intensity/
Precipitation in the first rainy season/
South China
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