台风风场简化理论模型的对比研究

Comparative Study among Various Parameterizations on the Modelling of Tropical Cyclone Wind Field

台风风场模型的研究对于台风风场极值风速、巨浪的精确预报以及与之相关的灾害评估研究是极具现实意义的。系统介绍了Kepert提出的台风风场线性解析模型和Foster提出的基于相似理论求解的半解析模型。在Kepert解析模型的基础上进行改进,引入沿高度变化湍流扩散系数模型和受速度影响的拖曳系数模型,用半解析的方法对风场进行求解。借助Dropsonde现场观测台风风速剖面数据对本文提出改进模型的准确性进行验证。利用三种理论模型对实测海上台风表面风场进行模拟,与H*wind风场数据进行比较,验证不同模型之间的差别,并定量分析不同模型对台风表面风场特性的模拟能力。

In order to investigate the dynamics and to predict the development of tropical cyclones(TC)boundary layer,theoretical and engineering models depicting the TC boundary layer flow are of great academic and practical interests.The engineering models have been widely utilized in the prediction of TC intensity,storm surge simulation and TC induced damage evaluation.Two widely accepted semi-theoretical models,including the analytical model proposed by Kepert and the similarity model by Foster,are reviewed systematically in the present study.An improved height-resolving model is proposed on the basis of Kepert’s model,where the turbulent diffusivity and drag coefficient parameterizations are incorporated.The improved model is validated through comparison with the observational data gathered from typhoon reconnaissance projects.Utilizing a set of archived over ocean surface wind field information provided by the H*wind database,rigorous comparisons among the three models are performed to examine their capability for accurately estimating the intensity,inflow angle,asymmetric characteristics and spatial distribution of the TC surface wind field.