Dynamics of the Tropical Troposphere

本项目涉及几个与飓风动力学和热带辐合带（ITCZ）相关的研究课题。研究的目的是增加对这些热带现象的动力学认识，并提高热带环流数值模拟的准确性。新发展的动力学理论是建立和扩展，并将利用数值模型的层次来实现研究的目标。以往对飓风中中旋涡和与位涡混合相关的地表压力快速下降的研究将扩展到三维数值模拟，并提供更好的物理方程，以提供对真实飓风流动的更完整的类比。冰效应和微观物理方面将在扩展模型的框架内进行研究。这将有助于更好地理解飓风近核动力学。对ITCZ和Hadley环流的模拟将扩展到包括潮湿动力学，并将以高分辨率进行，因为对地面风的观测表明ITCZ内的涡度结构表现出精细尺度的结构。这些都可能影响ITCZ的波动和击穿过程。另一类模式将用于研究热带和亚热带水汽的大尺度动力学控制。实地试验的观测数据将与理论和数值工作结合使用。湿动力学理论的发展将对热带气象学的广泛应用产生更广泛的影响。这将最终改善对热带气旋和飓风强度变化的预报。与水汽场相关的部分工作将改善天文设备驻扎地区的天气预报。通过让学生接触到数值模型的层次结构，将对研究生教育产生相当大的影响。

This project addresses several research topics that are relevant to the dynamics of hurricanes and the intertropical convergence zone (ITCZ). The objectives of the research are to increase the dynamical understanding of these tropical phenomena and to improve the accuracy of numerical simulations of tropical circulations. Recently developed dynamical theories are built upon and extended, and a hierarchy of numerical models will be utilized to achieve the objectives of the research. Previous studies of meso-vortices and rapid surface pressure falls associated with potential vorticity mixing in hurricanes will be extended to three dimensional numerical modeling with better physics equations to provide a more complete analogy to the flow of real hurricanes. Ice effects and microphysical aspects will be studied in the framework of the extended model. This will lead to better understanding of hurricane near-core dynamics. The simulation of the ITCZ and Hadley circulation will be extended to include moist dynamics and will be done at high resolution, because observations of surface winds suggest that vorticity structures within the ITCZ exhibit fine-scale structures. These may affect the undulation and breakdown process of the ITCZ. Another hierarchy of models will be employed to study the large-scale dynamical controls of water vapor in the tropics and subtropics. Observational data from field experiments will be used in conjunction with the theoretical and numerical work.Broader impacts of the development of the theory of moist dynamics will cover a wide range of applications in tropical meteorology. This will eventually lead to improved forecasting of tropical cyclones and of intensity changes of hurricanes. The part of the work related to water vapor fields will lead to improved weather prediction in areas where astronomical equipment is stationed. There will be a considerable impact on graduate student education by giving students access to a hierarchy of numerical models.