RAPID: Collection and Analysis of Data in Major Landfalling Hurricanes (2017)

飓风哈维的登陆是自2005年以来首次在美国登陆的主要飓风，也是现代气象雷达时代为数不多的4级或更高级别飓风之一。由这笔拨款资助的研究小组使用多普勒轮式雷达卡车从哈维的眼睛内部测量哈维。对数据的初步观察揭示了一个复杂的小规模强风结构组合。该奖项将允许该团队分析这些数据，并部署到飓风厄玛登陆时进行测量，与哈维进行比较和对比。该项目的影响应该是更好地了解强飓风中的低层风结构，这将通过向预报员、应急管理人员和工程师提供相关信息来改善公共安全。该项目是为了响应美国国家科学基金会关于哈维飓风研究的致同事信（NSF 17-128）。研究小组计划提高对登陆飓风的小规模流动的理解，重点是量化飓风边界层（HBL）的平均和湍流特性。在飓风哈维的观测资料中，观测到HBL中有卷状和条状的连续结构，眼壁上还有中涡旋和龙卷风级的环流。对这些数据的分析，连同来自飓风Irma的潜在数据，将用于解决以下问题：1)与较弱风暴相比，HBL特征（如卷状和条纹）是否相对更有能量，因此对调节飓风强度的贡献更大？眼壁环流的特点是什么？什么类型的环境支持这些眼壁循环？3)眼壁中涡旋、龙卷风尺度环流和HBL条纹等特征如何与局部高端损害相关？

The landfall of Hurricane Harvey was the first major hurricane landfall since 2005 in the United States, and one of only a handful of Category 4 or higher hurricane landfalls in the modern weather radar era. The research team that is funded by this grant made measurements of Harvey from inside the eye, using a Doppler on Wheels radar truck. An initial look at the data reveals a complex assembly of small scale, intense wind structures. This award will allow the team to analyze this data and to deploy to the landfall of Hurricane Irma to make measurements to compare and contrast with Harvey. The impact of the project should be a better understanding of the low-level wind structure in intense hurricanes, which would improve public safety by providing relevant information to forecasters, emergency managers, and engineers. The project is in response to the NSF Dear Colleague Letter on Hurricane Harvey research (NSF 17-128).The research team plans to improve understanding of small-scale flow in landfalling hurricanes, with a focus on quantifying the mean and turbulent properties of the hurricane boundary layer (HBL). Coherent structures in the HBL such as rolls and streaks were observed in the Hurricane Harvey data, along with mesovortices and tornado-scale circulations in the eyewall. Analysis of this data, along with potential data from Hurricane Irma, will be used to address the following questions: 1) Are HBL features such as rolls and streaks comparatively more energetic than in weaker storms and hence contribute more to modulating hurricane intensity? 2) What are the characteristics of eyewall circulations? What type of environment supports these eyewall circulations? 3) How do features such as eyewall mesovortices, tornado-scale circulations and HBL streaks correlate with localized high-end damage?