EMBRACE-AGS-Growth: Diagnosing Kinematic Processes Responsible for Precipitation Distributions in Tropical Cyclones

热带气旋，也称为飓风或台风，通过强风，风暴潮和暴雨对沿海社区构成重大威胁。对热带气旋的预测不准确可能导致社区准备不足，加剧这些强大风暴的影响。该项目旨在了解不同类型的降水或降雨如何影响热带气旋最大持续风速。根据空气在云中上升的速度，降水被分为四类。具有更快上升空气的云被称为对流，最高的云被称为深对流，较浅的云被称为中度对流和浅对流。最轻的降水被称为层状雨，它具有最少的上升空气。降水的类型可以根据雷达测量结果来确定。该项目研究了每种类型的降水如何通过对风暴结构的影响来影响风暴的最大持续风速。由于雷达可以识别不同类型的降水，该项目可能为热带气旋最大持续风速的预测提供新的见解。此外，该项目还将支持本科生研究，本科生导师计划，为成绩优异的学生提供奖学金，以及帮助易受热带气旋影响的社区了解和准备其影响的外联活动。该项目将使用一个全面的机载多普勒雷达数据集来研究降水模式如何扰动三维速度、垂直涡度、散度和绝对角动量等运动学场。由于机载雷达数据不包含热力学测量，该项目将使用一个完整的物理数值天气预报模式，以进一步探索降水模式是否与运动学扰动或热力学扰动（如湿度）更密切相关。此外，该项目将显示降水模式如何导致不同的非绝热加热廓线，并将使用线性模型来研究非绝热加热廓线如何导致平均涡旋结构的变化。降水的影响将在垂直风切变幅度不同的环境中进行评估，这可能会影响降水模式的分布。该项目的成果将导致一个新的整体模型，关于热带气旋中不同降水模式的作用，以及这种作用如何被不同的垂直风切变环境控制。该奖项反映了NSF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。

Tropical cyclones, also called hurricanes or typhoons, pose a significant threat to coastal communities through high winds, storm surge, and heavy rainfall. Poor predictions of tropical cyclones can lead to underprepared communities, exacerbating the impacts of these powerful storms. This project aims to understand how different types of precipitation, or rainfall, impact tropical cyclone maximum sustained wind speed. Precipitation is divided into four categories based on how fast the air is rising in clouds. Clouds that have faster rising air are called convection, with the tallest clouds called deep convection and the shallower clouds called moderate convection and shallow convection. The lightest precipitation is called stratiform rain and has the least amount of rising air. The type of precipitation can be identified based on its appearance on radar measurements. This project addresses how each type of precipitation influences the maximum sustained wind speed of the storm through their impact on storm structure. Since different types of precipitation can be identified on radar, this project may offer new insights into forecasting of tropical cyclone maximum sustained wind speed. In addition, this project will support undergraduate student research, an undergraduate mentorship program, a scholarship for a high achieving student, and outreach activities that will help communities susceptible to tropical cyclones understand and prepare for their impacts. The project will use a comprehensive airborne Doppler radar dataset to examine how precipitation modes perturb kinematic fields such as the three-dimensional velocity, vertical vorticity, divergence, and absolute angular momentum. Since airborne radar data does not contain thermodynamic measurements, the project will use a full physics numerical weather prediction model to further explore if precipitation modes are more closely associated with kinematic perturbations or thermodynamic perturbations such as in humidity. Furthermore, the project will show how precipitation modes lead to differing diabatic heating profiles and will use a linear model to examine how the diabatic heating profiles lead to changes in mean vortex structure. The impacts of precipitation will be evaluated in environments with differing vertical wind shear magnitudes, which can impact the distribution of the precipitation modes. The results of this project will lead to a new holistic model about the role of different precipitation modes in tropical cyclones and how that role is controlled by different vertical wind shear environments.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.