CAREER: A Comprehensive Assessment of Over-Ocean Tropical Cyclone Weakening

由于美国沿海地区面临飓风威胁的人口不断增加，因此必须准确预测这些风暴的未来行为，并有足够的提前时间制定适当的、具有成本效益的行动，以保护生命和财产。研究飓风强度的工作很多，但对仍在海洋上空减弱的飓风的研究相对较少，尽管公众认为预期影响与飓风类别有关，比如2018年的飓风佛罗伦萨。该项目将探索远离陆地而减弱的飓风的性质，以及近风暴环境的特征，以量化所有热带盆地海洋上减弱的变化。这项研究将调查在接近陆地时减弱的飓风，以评估附近的陆地如何改变这些减弱的路径，并促进预测此类事件的进展。该项目开发的开源编程工具将被共享，以确保科学的透明度，并扩大更多用户的可访问性。垂直风切变可以减弱热带气旋，但切变强度的范围与热带气旋的减弱有关。增强的大气湿度支持深层对流，但这种增强的湿度相对于风暴中心的位置似乎会影响风暴的强度。为了探究在这些不同环境中导致热带气旋减弱的物理过程，本研究将评估近风暴环境特征的空间分布以及在所有热带盆地的海洋上减弱事件的风暴相对框架内这些特征变化的相对时间。最新的全球再分析将用于环境领域，对流及其随时间演变的空间评估（由地球同步红外图像显示）将突出热带气旋对其环境的响应。除了推进对这些风暴的基本了解之外，该项目还将制作一个由开源Python工具组成的热带气旋分析工具包，以加快更广泛的研究社区的科学研究时间。工具包示例将在课堂上开发和测试，以支持热带气旋动力学和编程实践的教学，从而形成可纳入各机构现有课程的模块。本项目由美国国家科学基金会（NSF）物理与动态气象计划（PDM）和促进竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The expanding population along U.S. coastlines who are at risk from hurricanes makes it essential to accurately predict the future behavior of these storms with sufficient lead time to enact appropriate, cost-effective actions that protect life and property. Much work has investigated hurricane intensification, but comparatively little effort has been invested in studying hurricanes that weaken while still over the ocean despite public perception of expected impacts being tied to hurricane category, such as Hurricane Florence in 2018. This project will explore the nature of hurricanes that weaken away from land, as well as characteristics of the near-storm environment, to quantify how over-ocean weakening varies across all tropical basins. The research will then investigate hurricanes that weaken on approach to land in order to evaluate how nearby land modifies these weakening pathways and facilitate advances in forecasting such events. Open-source programming tools developed by this project will be shared to ensure scientific transparency and expand accessibility to more users.Vertical wind shear can weaken a tropical cyclone, yet a range of shear magnitudes is associated with tropical cyclone weakening. Enhanced atmospheric moisture supports deep convection, but the location of this enhanced moisture relative to the storm center appears to affect the storm’s intensity. To interrogate the physical processes responsible for tropical cyclone weakening in these varied environments, this study will assess the spatial distribution of near-storm environmental characteristics and the relative timing of changes in those characteristics within a storm-relative framework for over-ocean weakening events in all tropical basins. The latest global reanalysis will be investigated for environmental fields, and spatial assessment of convection and its evolution over time—revealed by geostationary infrared imagery—will highlight the tropical cyclone’s response to its environment. Beyond advancing fundamental understanding of these storms, this project will craft a tropical cyclone analysis toolkit comprised of open-source Python tools to accelerate time-to-science for the broader research community. Toolkit examples will be developed and tested in the classroom to support teaching of tropical cyclone dynamics and programming practices, leading to modules that can be incorporated into existing curricula across institutions.This project is jointly funded by NSF Physical and Dynamic Meteorological program (PDM), and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.