Collaborative Research: Dynamic and Thermodynamic Control of Tropical Cyclone Intensity in Sheared Environments

合作研究：切变环境中热带气旋强度的动态和热力学控制

• 批准号: 0649946
• 负责人: Michael Montgomery
• 金额: $ 33.09万
• 依托单位: Naval Postgraduate School
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0649946&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamic; Thermodynamic; Control

In this collaborative research effort, the Principal Investigators will undertake a comprehensive investigation of the physics of the interaction between tropical cyclones and sheared flow in which they are embedded, focusing on the mutual operation of dynamic and thermodynamic processes. They hypothesize that tropical cyclones are weakened by the injection of low-entropy, middle level air into the vortex core by vortex Rossby waves excited by the interaction between the vortex and environmental shear flow. The research emphasis (mutual importance of dynamical and thermodynamical processes) departs from most previous investigations, which have focused almost exclusively on direct dynamical effects. The research will have a direct path to improved prediction of tropical cyclones through the improvement of an operational forecast model.The starting point of the research is two key theoretical developments that have matured over the previous decade: the quantitative theory of thermodynamic control of hurricane intensity, and the theory governing the generation, behavior and wave/mean flow interaction of vortex Rossby waves. From these points, the Principal Investigators will develop an extended theory for the generation and maintenance of vortex Rossby waves as a consequence of the interaction between vortices and ambient shear flow, addressing as well the rate at which these waves flux passive tracers in and out of the vortex core region. This theory will be used as guidance in modifying the thermodynamic cycle to account for dry air injection at middle levels by vortex Rossby waves. Having developed this theoretical framework, the Principal Investigators will test it using a suite of models, focusing on fully three dimensional simulations at high resolution using a nonhydrostatic model. It is expected that the theory will be modified based on the results of these tests. Finally, the researchers will use this theory to develop a parameterization of Rossby wave-induced fluxes of low entropy air, for use in axisymmetric models, including the aforementioned operational forecast model.The intellectual merit of the project: The nature of the interactions between tropical cyclones and the ambient wind field has remained enigmatic for many years. Previous efforts to understand and quantify this interaction have focused almost exclusively on the dynamics. In this project, the researchers will marry thermodynamic and dynamic aspects of the interaction to create a general and complete description of the process.The broader impacts of the project: The skill of hurricane intensity forecasts remains poor in spite of substantial advances in the skill of storm track forecasts. Research on tropical cyclone intensity is a high priority under the U.S. Weather Research Program. This research may well lead to an advanced understanding of the effect of environmental shear on hurricane intensity; such advanced understanding will be directly incorporated into an existing hurricane intensity prediction model, thereby leading directly, and within the time frame of this award, to improved hurricane intensity forecasts. In the process of carrying out this research, the Principal Investigators will train advanced graduate students in the science of hurricanes and hurricane prediction, thereby helping to foster a new generation of researchers and forecasters.

在这项合作研究工作中，首席研究人员将对热带气旋与嵌入的剪切流量之间相互作用的物理学进行全面研究，重点是动态和热力学过程的相互操作。 他们假设通过向涡流和环境剪切流量之间的相互作用激发的涡旋rossby波触发了低渗透性，中层空气中的热带气旋削弱。 研究的重点（动力学和热力学过程的相互重要性）与以前的大多数研究相偏离，这些研究几乎完全关注直接动态效应。 这项研究将通过改进操作预测模型来改善热带气旋的预测直接途径。研究的起点是在过去十年中成熟的两个关键理论发展：飓风强度的热力学控制的定量理论，以及vortsex rosss by vorvesby wavesby wavesby wavesby wavesby wavesby wavesby wavesby wave soss her飓风控制的定量理论。 从这些角度来看，主要研究人员将开发出一种扩展的理论，用于生成和维持涡旋波浪波，这是由于涡流与环境剪切流之间的相互作用的结果，并解决了这些波在涡旋核区域内外的磁波无源示踪剂的速度。 该理论将用作修改热力学循环的指导，以说明涡旋波浪在中间级别的干燥空气注射。 在开发了这个理论框架之后，主要研究人员将使用一系列模型对其进行测试，并使用非静态模型以高分辨率的全部三维模拟进行测试。 预计该理论将根据这些测试的结果进行修改。 最后，研究人员将使用该理论来开发罗斯比波诱导的低熵空气通量的参数化，以用于轴对称模型，包括上述操作预测模型。 以前的理解和量化这种相互作用的努力几乎完全集中在动态上。 在这个项目中，研究人员将结合相互作用的热力学和动态方面，以对该过程进行一般和完整的描述。该项目的更广泛影响：尽管飓风强度预测的技能在风暴轨道预测的技巧方面取得了重大进展，但仍很差。 在美国天气研究计划下，对热带气旋强度的研究是高度重视。 这项研究很可能会导致对环境剪切对飓风强度的影响的深入了解。这种先进的理解将直接纳入现有的飓风强度预测模型中，从而直接领导该奖项的时间范围，以改善飓风强度的预测。 在进行这项研究的过程中，首席研究人员将培训飓风和飓风预测科学的高级研究生，从而帮助培养新一代的研究人员和预报员。