一次近海台风的移动、发展和结构的分析

AN ANALYSIS OF THE MOVEMENT, GROWTH AND STRUCTURE OF AN OFF-SHORE TYPHOON

本文对国际台风业务试验(TOPEX)期间的8211(Cecil)台风的近海右折北上、强烈发展及其结构作了综合分析指出,这次台风的近海右折北上与来自南半球经非洲沿岸的越赤道气流的加强和维持有密切关系;台风的近海强烈发展与台风所处的有利环境流场有关。在涡度平衡中,散合项及积云对流作用很重要,涡度的垂直输送作用也不容忽视;在台风近海发展期间其温度结构并不对称,涡度从低层向高层加强和发展,涡度和垂直速度分布大体呈对称状态。

A comprehensive analysis is made of the off-shore right-turning and north-moving,violent growth and structure of typhoon 8211 (Cecil) during the International Typhoon Operational Experiment (TOPEX). It is noted that the right-turning and northward movement of the typhoon is closely related to the intensification and maintenance of the cross-equatorial flow which set out in the southern hemisphere and moved along the African coast, and its off-shore violent growth has much to do with the favorable environmental flow field. The divergence or convergence term and cumulative convection play an important role in the vortex equilibrium and the vertical vortex transport should not beoverlooked. The temperature structare is not in symmetry during the off-shore development.The vortex develops and intensifies from the lower to higher level, and the vortex and the vertical velocity distribution are roughly in symmetry.