厄尔尼诺事件的类型、强度对海南岛秋汛期降水的影响  

Impacts of Types and Intensities of El Nino Events on Precipitation in Autumn Flood Season of Hainan Island

作　　者：汪婉婷 吴慧[2,3] 蔡夏影[1] 徐实 Wang Wanting;Wu Hui;Cai Xiaying;Xu Shi(Hainan Meteorological Service Center,Haikou 570203,China;Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province,Haikou 570203,China;Hainan Climate Center,Haikou 570203,China)

机构地区：[1]海南省气象服务中心,海口570203 [2]海南省南海气象防灾减灾重点实验室,海口570203 [3]海南省气候中心,海口570203

出　　处：《气象与环境科学》2024年第1期88-96,共9页Meteorological and Environmental Sciences

基　　金：海南省气象局青年基金项目(HNQXQN202002);国家自然科学基金(41765005);海南省重点研发计划项目(ZDYF2019113)。

摘　　要：利用1961—2018年逐月Ni?o关键区海温指数资料、NCEP/NCAR再分析资料及国家气象观测站降水量资料,在定义了厄尔尼诺事件的类型和强度的基础上,利用相关分析和合成分析方法,分析了近58年厄尔尼诺事件的不同类型和强度对海南岛秋汛期降水的影响及其相应的大气环流和水汽输送场的差异。结果表明,厄尔尼诺事件总体有利于海南岛秋汛期降水偏少,但存在类型和强度上的差别。其中轻度中部型厄尔尼诺事件年全岛平均降水量偏少32.5%,偏少概率较气候概率上升了25.0%,降水异常的空间分布表现为西南局部地区的偏多、其余地区的偏少;中等及以上强度东部型厄尔尼诺事件年降水量平均偏少21.7%,偏少概率上升了11.7%,轻度东部型厄尔尼诺事件年降水量平均偏少15.8%,偏少概率上升了7.5%,两者的降水异常空间分布为一致性偏少。海南岛秋汛期降水异常与大气环流和水汽输送密切相关。不同类型和强度的厄尔尼诺事件年可能主要通过影响沃克环流的位置、强度的不同程度变化,造成风场、位势高度场、海平面气压场、垂直速度场、水汽通量及其散度场响应程度上的差异,最终使海南岛秋汛期降水发生不同程度的减少。By using the 19612018 monthly sea surface temperature(SST)index data in the Nino key area,NCEP/NCAR reanalysis data and precipitation data of National Meteorological Observatory as well as the correlation analysis and composite analysis methods,this article analyzes the impact of different types and intensities of El Nino events on precipitation in autumn flood season in recent 58 years of Hainan Island and the corresponding differences in atmospheric circulation and water vapor transport field on the basis of defining the types and intensities of El Nino events.The results demonstrate that El Nino events make for the decrease of the autumn precipitation generally,but they have differences in type and intensity.In the years with central Pacific El Nino events in light intensity,the probability of 32.5%less than average precipitation in the whole island of Hainan increases by 25%relative to the climatic probability.Moreover,the spatial distribution of precipitation anomaly is more in some southwestern areas but less in other areas of Hainan Island.In addition,the probability of 21.7%less than average precipitation increases by 11.7%compared to the climatic probability in the years with eastern Pacific El Nino events in medium and higher intensities,while the probability of 15.8%less than average precipitation increases by 7.5%relative to the climatic probability in the years with eastern Pacific El Nino events in light intensity.The spatial distributions of precipitation anomalies of both them are less consistent.The precipitation anomaly in autumn flood season of Hainan Island is closely related to atmospheric circulation and water vapor transport.In the years with different types and intensities of El Nino events,the El Nino events can result in differences in response degrees of wind field,geopotential height field,sea-level pressure field,vertical velocity field,water vapor flux and divergence field by affecting the changes in the location and intensity of Walker circulation in varying degrees,which finally re

关 键 词：厄尔尼诺事件 类型 强度 海南岛秋汛期降水 

分 类 号：P461.2[天文地球—大气科学及气象学]