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

飓风哈维是2005年以来登陆美国的第一个大型飓风，也是现代天气雷达时代为数不多的四级或更高级别飓风之一。 由该基金资助的研究小组使用多普勒雷达卡车从眼睛内部对哈维进行了测量。 对数据的初步研究揭示了一个复杂的小规模，强烈的风结构。 该奖项将允许该团队分析这些数据，并部署到飓风厄玛的登陆地进行测量，以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烈飓风中的低空风结构，这将通过为预报员，应急管理人员和工程师提供相关信息来改善公共安全。 该项目是对NSF致同事关于飓风哈维研究的信（NSF 17-128）的回应。研究团队计划提高对登陆飓风中小尺度流动的理解，重点是量化飓风边界层（HBL）的平均和湍流特性。 在飓风哈维的数据中观察到了高强度边界层中的相干结构，如卷和条纹，沿着眼壁中的中涡旋和龙卷风尺度环流。 对这些数据的分析，沿着飓风厄玛的潜在数据，将用于解决以下问题：1）HBL特征（如卷和条纹）是否比较弱的风暴更具活力，因此对调节飓风强度的贡献更大？ 2)眼壁环流的特征是什么？ 什么样的环境支持这些眼壁循环？ 3)眼壁中涡、龙卷风尺度环流和HBL条纹等特征如何与局部高端破坏相关联？

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?