AGS-PRF: Examining the Response of Tropical Cyclone Precipitation Structure to Climate Change Using Idealized and Realistic Models

AGS-PRF：使用理想化和现实模型检查热带气旋降水结构对气候变化的响应

• 批准号: 2204138
• 负责人: Alyssa Stansfield
• 金额: $ 19万
• 依托单位: Stansfield, Alyssa M
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2204138&HistoricalAwards=false
• 关键词: AGS; PRF; Examining; Response; Tropical

Tropical cyclones (TCs) are weather systems made up of rotating thunderstorms that usually form in the tropics and that can cause injuries, fatalities, and expensive property damage when they move over land. While coastal residents are often most concerned about flooding from TC landfalls, TC precipitation and associated flooding can extend hundreds of miles inland. Although it is well-established that TC precipitation rates are expected to increase in the future due to climate change, the scientific community is less certain about how the patterns of TC precipitation may change, which has implications for issuing the most accurate flood warnings and evacuation mandates ahead of TC landfalls. This project will explore how TC precipitation structure will be impacted by climate change since structural changes may shift the distribution of precipitation within TCs, which could impact flooding patterns. TC precipitation comes from both the inner core, commonly known as the eye wall, and outer rainbands. A more complete understanding of how TC precipitation in the inner core and outer rainband regions is related and how precipitation may change in these two regions because of climate change can aid TC forecast modelers in adapting their models to the changing climate, which will in turn help emergency managers and decision makers save lives in areas prone to TC landfalls.Previous modeling studies on TC precipitation and climate change have used coarse-resolution models that cannot resolve TC precipitation structures. Recent observational studies using about 20 years of satellite data found a decreasing trend in TC inner core precipitation and an increasing trend in TC outer rainband precipitation, while models using grid spacings of tens of kilometers or coarser have projected conflicting changes in inner core versus outer rainband precipitation increases due to climate change. This research will use an idealized high-resolution model with explicitly-resolved convection to increase the understanding of how three-dimensional precipitation structures within TCs are impacted by atmospheric and sea surface temperature warming. Results will provide insight into discrepancies between observed trends and climate model predictions of changes in TC precipitation structure. Physical mechanisms behind any notable changes in precipitation structure will be explored. Beyond the idealized simulations, an analysis of pseudo-global warming simulations run at the same resolution as the idealized simulations will show if the results discovered with the idealized simulations apply to TCs in more Earth-like environments and how precipitation during TC landfalls may change in the future.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.

热带气旋(TC)是由通常在热带形成的旋转雷暴组成的天气系统，当它们在陆地上移动时，可能会造成人员伤亡和昂贵的财产损失。虽然沿海居民通常最担心热带气旋登陆引发的洪水，但热带气旋降水和相关洪水可能会向内陆延伸数百英里。尽管众所周知，由于气候变化，未来热带气旋的降雨率将会增加，但科学界对热带气旋降水模式可能如何变化不太确定，这对在气旋登陆之前发布最准确的洪水警报和疏散命令具有影响。本项目将探讨热带气旋降水结构将如何受到气候变化的影响，因为结构变化可能会改变热带气旋降水的分布，这可能会影响洪水模式。TC降水既来自内部核心，也就是通常所说的眼壁，也来自外部雨带。更全面地了解热带气旋内、外雨带降水的关系，以及这两个区域的降水可能因气候变化而发生变化，有助于热带气旋预报模型师调整他们的模式以适应气候变化，从而帮助应急管理人员和决策者拯救易发生热带气旋登陆地区的生命。以往对气旋降水和气候变化的模拟研究使用的是无法解析气旋降水结构的粗分辨率模式。最近利用近20年的卫星资料进行的观测研究发现，由于气候变化，热带气旋核心降水呈减少趋势，而热带气旋外部雨带降水呈增加趋势，而使用数十公里或更粗网格间距的模式则预测出内部核心降水与外部雨带降水增加的相互矛盾的变化。这项研究将使用一个具有显式分解对流的理想化高分辨率模式，以增加对TCS内三维降水结构如何受到大气和海洋表面温度变暖的影响的理解。结果将提供关于TC降水结构变化的观测趋势和气候模型预测之间的差异的洞察。将探索降水结构任何显著变化背后的物理机制。除了理想化的模拟，以与理想化的模拟相同的分辨率运行的伪全球变暖模拟的分析将表明，理想模拟发现的结果是否适用于更类似地球的环境中的TC，以及TC登陆期间的降水在未来可能会发生什么变化。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。