摘要
利用“登陆台风Winnie(1997)的数值模拟研究Ⅰ”的数值模拟结果 ,讨论了Winnie(1997)台风在登陆后变性阶段和重新加强阶段的环流、动力和热力结构特征以及演变过程。在结构上 ,变性阶段主要完成了从基本对称的垂直分布到斜压非对称分布的转换。在变性阶段的初期 ,热力和动力以及环流结构上都还留有一些热带气旋的影子 ,但是在强度和空间分布上已经发生了明显的变化 ,同时也反映了台风登陆后由于下垫面的变化 ,使来自海面的暖湿水汽输送呈明显的不对称分布 ,导致热力结构上的不对称分布。到变性阶段的后期 ,无论从环流结构还是动力结构上 ,都形成了和冷暖锋相对应的倾斜分布特征 ,并且和冷空气对应的锋区在低层侵入到气旋中心 ,使热带气旋经过变性阶段最终演变为锋面气旋。在重新发展阶段 ,通过与西风带低槽的结合 ,变性后的气旋获得了重新发展的机会。并且在此过程中得到了一次来自附近洋面的高暖湿能量的输送 ,也为发展提供了有利的条件 ,使变性后的气旋进一步加强为成熟的温带气旋。
By use of the result of simulation in part I of this study, the characteristics of typhoon during transformation stage and re-intensification stage are analyzed in circulation and dynamical and thermodynamic structures. The main course during the transformation stage is the transform from a symmetric tropical cyclone to a baroclinic asymmetric cyclone. At the beginning of transformation stage, some characters remain as those of tropical cyclone though the intensity and distribution of variables have changed obviously. Also the transporting of warm and wet air from ocean is asymmetric distribution due to the change of underlying surface after landfall. At the end of transformation stage a frontal cyclone is formed, since that the front zone intruded into the cyclone center in the lower level, and the slant characteristics of circulation and dynamical structure associated with front are developed. The neutral cyclone developed again in the re-intensification stage after combining the west trough in the upper level, the import of warm and moist flow from sea when the cyclone located at Bohai Sea does favor of its development during the stage.
出处
《气象学报》
CSCD
北大核心
2002年第5期560-567,共8页
Acta Meteorologica Sinica
基金
国家重点基础研究项目 (G19980 40 90 7)
高等学校实验室访问学者基金。
关键词
台风
变性
数值模拟
结构分析
下垫面
纬度
Typhoon transformation, Numerical simulation, Structure analysis.