西北太平洋双热带气旋相互作用统计分类及其特征分析

STATISTICAL CLASSIFICATION AND CHARACTERISTICS ANALYSIS OF BINARY TROPICAL CYCLONES OVER THE WESTERN NORTH PACIFIC OCEAN

采用中国气象局与上海台风研究所提供的1949—2007年西北太平洋热带气旋最佳路径资料,统计分析了西北太平洋上的双(多)热带气旋相互作用现象。针对统计出的双热带气旋样本,根据相互作用两气旋的单独移动路径和它们相互作用的路径特征,归纳得到7种相互作用类型(A^G),并用聚类分析方法拟合得到每种类型的平均回归路径。分析讨论了各相互作用类型的登陆情况、季节规律和两气旋共存时间等一般特性,着重分析在相互作用过程中大尺度背景场的变化特征。利用7种类型双热带气旋6小时一次的整层平均引导气流图,从每种类型中选取10个典型相互作用的个例,将它们相互作用发生、发展和结束阶段的整层平均引导气流进行平均,得到各相互作用类型在不同阶段的典型引导流场。

Using the best track data of tropical cyclones provided by the China Meteorology Agency and Shanghai Typhoon Institute over the western north Pacific from 1949 to 2007, we pick out the binary tropical cyclones and multi-tropical cyclones interaction samples. According to the features of each tropical cyclone track and their interaction track in the binary system interaction sample, seven interaction types are established. A cluster analysis technique is used to obtain the mean trajectory of the west and east tropical cyclone in each type. These types are then analyzed in terms of trajectory, landfall, seasonality and coexistent lifetime. In addition, the large-scale patterns of atmospheric circulation with each interaction type are emphatically investigated. According to the mean steering stream figures per six hours of every binary system, the mean steering stream of ten representative interaction examples which are chose from each interaction type are averaged. Then, the model figures of mean stream in each type at the beginning, middle and final phase are got to describe the binary tropical cyclones interaction.