The Horizontal and Vertical Structure of Tropical Cyclones: Theory, Observations, and Idealized Modeling

建议的知识内容：准确预测热带气旋的大小和强度仍然是现代气象学的突出挑战之一。在这个项目中，两个不同但互补的工具将一起使用，以了解是什么过程控制和调节热带气旋风场的水平和垂直结构。这些工具将是：1)使用天气研究和预报模型（WRF）的一个版本进行高分辨率模拟，该模型已经过修改，以支持高度理想化和受控环境下的热带气旋模拟；2)由首席研究员（PI）在过去六年中开发和使用的线性但复杂的非对称和对称涡旋动力学模型，称为三维涡旋摄动分析和模拟（3DVPAS）。自20世纪80年代Kerry Emanuel关于成熟飓风垂直结构理论的开创性工作以来，人们很少关注垂直结构在控制当前强度和未来强度变化中的作用。PI将使用WRF模型来模拟具有各种垂直和水平结构的气旋，这些气旋嵌入在控制平均流量和平均切变速度的环境中。3DVPAS将用于评估这些结构变化对未来增强的影响，并分析对流不对称（如螺旋带）在改变对称风场的垂直和水平结构中的作用。两种研究方法的结果将与NOAA/HRD和雨带强度实验（RAINEX）期间获得的飓风风场雷达观测结果进行比较和验证。该提案的更广泛影响：这项工作的更广泛影响将是增加对飓风风场大小和结构演变的理解。这不仅可以更好地预测路径和强度，还可以更好地预测登陆风暴的观察和预警区域的大小，这对受影响地区造成了巨大的损失。进一步发展和最终传播理想化的建模系统将有利于研究界。

Intellectual content of the proposal: The accurate prediction of the size and intensity of tropical cyclones remains one of the prominent challenges in modern meteorology. In this project, two distinct but complementary tools will be used together to understand what processes control and modulate both the horizontal and vertical structure of the tropical cyclone wind field. These tools will be: 1) high-resolution simulations using a version of the Weather Research and Forecasting Model (WRF) which has been modified to support tropical cyclone simulations in highly idealized and controlled environments, and 2) a linear but sophisticated model of asymmetric and symmetric vortex dynamics that has been developed and used by the Principal Investigator (PI) over the last six years, known as Three-Dimensional Vortex Perturbation Analysis and Simulation (3DVPAS). Since pioneering work of Kerry Emanuel in the 1980s on the theory of the vertical structure of a mature hurricane, little attention has been paid to the role that vertical structure plays in controlling current intensity and future intensity changes. The PI will use the WRF model to simulate cyclones with a variety of vertical and horizontal structures, embedded in environments with controlled mean flow and mean shear speeds. 3DVPAS will be used to assess the implications of these structure changes for future intensification, and to analyze the roles of convective asymmetries (such as spiral bands) in changing the vertical and horizontal structure of the symmetric wind field. Results from both methods of study will be compared and validated against radar observations of the hurricane wind field, obtained from NOAA/HRD and during the Rainband Intensity Experiment (RAINEX). Broader impacts of the proposal: The broader impacts of this work will be to increase understanding of the evolution of the size and structure of the hurricane wind field. This potentially will lead to better forecasting of not only track and intensity, but also of the appropriate sizes for the watch and warning zones for landfalling storms, which have enormous cost impacts for the affected areas. Further development and eventual dissemination of the idealized modeling system will benefit the research community.