CMG: Analysis of Transport, Mixing, and Coherent Structures in Hurricane Intensity

CMG：飓风强度中的传输、混合和相干结构分析

• 批准号: 0715426
• 负责人: Michael Montgomery
• 金额: $ 139.57万
• 依托单位: Naval Postgraduate School
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0715426&HistoricalAwards=false
• 关键词: CMG; Analysis; Transport; Mixing; Coherent

This project studies hurricane dynamics with a particular emphasis on processes that affect the intensity of the tropical cyclone by mixing in moist air or dry air from different sources. Since penetration to the storm core or eye-wall is a nonlinear mixing problem, the investigators intend to apply methods from dynamical systems theory to help them understand transport and mixing processes, both on the scale of the eye/eye-wall system with its mesovortices in the eye-wall, and on the scale of the vortex as a whole. Part of the motivation for this work is that existing theory for maximum wind intensity, based on assumptions of axisymmetry can significantly under-predict the intensities seen in high-resolution numerical models of hurricanes. The formation of eye-wall mesovorticies and latent heat release from moist air transported asymmetrically into the hurricane eye-wall may help explain this difference.The work to be done includes analyzing output from high-resolution hurricane simulations to determine distinguished hyperbolic orbits and their stable and unstable manifolds, implementing new methods for analyzing Lagrangian mixing, finding low-dimensional approximations to phases of hurricane evolution, and a search for a set of parameters that may be used to predict maximum wind intensity.It is anticipated that the results of this theoretical work will help in the design of future field experiments, contribute to a better understanding of the processes responsible for fluctuations in hurricane intensity, and provide a basis for better predictions of hurricane intensity.

该项目研究飓风动力学，特别强调通过混合不同来源的潮湿空气或干燥空气来影响热带气旋强度的过程。 由于穿透风暴核心或眼壁是一个非线性混合问题，研究人员打算应用动力系统理论的方法来帮助他们理解传输和混合过程，无论是在眼壁中存在中涡的眼/眼壁系统的规模上，还是在整个涡旋的规模上。 这项工作的部分动机是，基于轴对称假设的现有最大风强度理论可能会严重低估高分辨率飓风数值模型中的强度。 眼壁中涡的形成和不对称地输送到飓风眼壁的潮湿空气的潜热释放可能有助于解释这种差异。要做的工作包括分析高分辨率飓风模拟的输出，以确定独特的双曲轨道及其稳定和不稳定流形，实施分析拉格朗日混合的新方法，找到飓风相位的低维近似值 预计，这项理论工作的结果将有助于未来现场实验的设计，有助于更好地理解造成飓风强度波动的过程，并为更好地预测飓风强度提供基础。