The Origin of Rotation in Tornadoes

本研究旨在探讨下沉气流和地表旋转在龙卷风旋转的“种子”形成中的相对作用。这项研究将有助于解释在不同情况下导致龙卷风形成的基本过程。具体地说，表面摩擦的作用将通过几个数值模拟以及摩擦参数化的不同实现来量化。除了培训研究生外，这项研究还将通过广播节目讨论研究和一般的恶劣天气，吸引公众参与。为了研究这些问题，涡度分解技术将应用于雷暴的高分辨率全物理模拟以及理想化的下沉气流模拟。本研究将应用沿轨迹涡度分解技术进行理想化数值模拟。对该问题的数学处理将把微分几何的各个方面引入强风暴领域，并为涡旋动力学的形式化描述提供了一个新的视角。

This study seeks to investigate the relative roles of downdrafts and surface rotation in the "seed" formation of rotation in tornadoes. This research will lead to explanations of the fundamental processes that lead to the formation of tornadoes in different situations. Specifically, the role of surface friction will be quantified using several numerical simulations as well as different realizations of friction parameterizations. In addition to the training of graduate students, this study will engage the public through radio segments discussing the research and severe weather in general. To investigate these problems, a vorticity decomposition technique will be applied to high-resolution full-physics simulations of thunderstorms as well as to idealized downdraft simulations. The research will apply a vorticity decomposition technique along trajectories to idealized numerical simulations. The mathematical treatment of the problem will introduce aspects of differential geometry into the severe storms community and offer a new perspective on the formal description of vortex dynamics.