在分析热带风暴眼壁和螺旋雨带中尺度波动特征最新研究的基础上,指出这些研究所忽略的问题,其中包括重力惯性波和涡旋Rossby波波解存在的前提条件和约束、理论分析与观测研究存在的差异等。提出一种基于准平衡动力条件下,热带风暴内中尺度扰动涡散运动共存时,区别于标准模混合的不可分的混合涡旋Rossby-重力惯性波,并讨论了位涡守恒条件下这一类不可分混合波的可能成波机制。利用高分辨率的模式大气资料,采用非对称波分量的分解方法分析了Bonnie飓风中的中尺度波动特征,结果表明,热带风暴中1波型扰动既具有涡旋波性质,但也存在散度扰动的变化,而2波型扰动则体现了明显的不可分混合波的特性。
In this study, recent advances in studying wave characteristics in tropical storms are reviewed and some key issues that have been neglected in previous studies are discussed, including the limitations in wave solutions of inertial-gravity waves and vortex Rossby waves as well as departures of theoretic analyses from observational research. Furthermore, mixed vortex Rossby inertial-gravity waves in tropical storms are explored in the context of quasi-balanced dynamics, showing the co-existence of rotational and divergent flows associated with these waves. The mixed-wave dynamics are investigated using the potential vorticity conservation principle, and then the high resolution simulation of Hurricane Bonnie (1998) is used to diagnose these wave characteristics with the method of asymmetric wave decomposition. It is shown that vortex Rossby waves are more prominent with the wavenumberone component which still have strong divergent flow, while the mixed wave features are more significant with wavenumber-two component.