Collaborative Research: Understanding the Turbulent Dynamics of Convective Bursts and Tropical Cyclone Intensification Using Large Eddy Simulations and High-Order Numerics

合作研究：利用大涡模拟和高阶数值了解对流爆发和热带气旋增强的湍流动力学

• 批准号: 2121367
• 负责人: Simone Marras
• 金额: $ 28.9万
• 依托单位: New Jersey Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2121367&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; Turbulent; Dynamics

Hurricane intensity changes are governed by a number of complex and competing processes that are difficult to simulate. This project will address one of the key uncertainties in hurricane intensity, the turbulent mixing of air and moisture in the inner core of a hurricane. In particular, the study will focus on convective bursts, which are roughly equivalent to large thunderstorms near the hurricane’s eyewall, and how they influence the intensification cycle. Rapid intensification changes have occurred in many recent high-impact storms and while forecasters know the general conditions that may lead to rapid intensification, the exact timing and magnitude of those changes are difficult to predict. This research will provide additional information to the scientific community which may result in improved numerical modeling of these storms. The project will also provide training and outreach opportunities to several students, thereby training the next generation of scientists.The goal of the project is to understand the fundamental physics of tropical cyclone intensification with an emphasis on the role of turbulent dynamics. The researchers aim to 1) understand the turbulent nature of the convective burst cycle from formation to maturation and decay during intensification, and 2) identify the roles of axisymmetric and asymmetric dynamics in the intensification of tropical cyclones in a fully turbulent regime characterized by a wide range of energetic length scales with a minimally dissipative dynamic core. To address these aims, the researchers plan to conduct very high-resolution Large Eddy Simulations (LES) of tropical cyclones at 50m horizontal and vertical grid spacing using the newly developed ClimateMachine community model. The model output will be analyzed using diagnostic budget calculations for angular momentum, kinetic energy, and thermal energy equations in a Eulerian and Lagrangian reference from to enable improved physical insight.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.

飓风强度的变化受许多复杂和相互竞争的过程控制，这些过程很难模拟。该项目将解决飓风强度的主要不确定性之一，即飓风内核中空气和水分的湍流混合。特别是，这项研究将集中在对流爆发，这大致相当于飓风眼壁附近的大雷暴，以及它们如何影响强化周期。在最近的许多高影响风暴中发生了快速强化变化，虽然预报员知道可能导致快速强化的一般条件，但这些变化的确切时间和幅度很难预测。这项研究将为科学界提供更多的信息，可能会改善这些风暴的数值模拟。该项目还将为若干学生提供培训和外联机会，从而培养下一代科学家，该项目的目标是了解热带气旋强化的基本物理学，重点是湍流动力学的作用。研究人员的目标是：1）了解对流爆发周期从形成到成熟和加强过程中的衰变的湍流性质; 2）确定轴对称和非对称动力学在热带气旋加强中的作用，该热带气旋处于完全湍流状态，其特征是具有最小耗散动力核心的各种能量长度尺度。为了实现这些目标，研究人员计划使用新开发的ClimateMachine社区模型，以50米的水平和垂直网格间距对热带气旋进行非常高分辨率的大涡模拟（LES）。模型输出将使用欧拉和拉格朗日参考中的角动量，动能和热能方程的诊断预算计算进行分析，以提高物理洞察力。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。