CAREER: From Dust to Drought: Understanding the Multi-Scale Relationship between the Saharan Air Layer and Caribbean Water Stress

撒哈拉空气层(SAL)是一种众所周知的气象现象，来自撒哈拉沙漠的干燥空气和沙尘平流越过大西洋。由于SAL在空气质量和抑制热带气旋形成方面发挥的作用，SAL受到了重大的科学关注。最近的研究还表明，沙尘暴可能会影响加勒比地区的干旱。该项目将处理导致加勒比旱灾发展的因素，并特别侧重于波多黎各。该项目的社会影响很大，因为加勒比群岛严重依赖定期降水来满足农业、生态和城市用水需求。首席研究员是加勒比干旱资源组织SECARIBE的创始成员之一，将与当地水资源管理人员和业务天气预报员分享研究成果。该项目还包括一个重要的教育和宣传部分，包括为期两周的强化暑期课程、喷雾讲习班、参加海洋骚乱K-8活动，以及与当地电视台一起制作一个兴趣片段。该项目将开创三大创新：(1)开发一个数十年的SAL事件及其形态行为的数据集；(2)评估SAL中的形态行为；(1)作为嵌入的沙尘负荷的函数；以及(3)确定SAL目的地区域的蒸发需求作为沙尘负荷的函数。虽然之前的研究明确认为沙尘是一种降雨抑制剂，但这是第一次尝试通过蒸发需求将沙尘变暖效应扩展到地表干旱动态。该项目将使用气候分析和使用WRF-Chem的数值模拟来解决三个主要假设：1)在加勒比海干旱年份，SAL更频繁和/或更强，2)SAL内的悬浮沙尘积极影响大西洋SAL的演变，3)沙尘驱动的变暖增加了SAL附近的蒸发需求，促进了闪旱。该项目由物理和动力气象学、已建立的刺激竞争研究计划(EPSCoR)以及气候和大型动力共同资助。该奖项反映了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。

The Saharan Air Layer (SAL) is a well-known meteorological phenomenon where dry air and dust from the Saharan Desert is advected across the Atlantic Ocean. The SAL has received significant scientific attention due to the role that it plays in air quality and inhibiting tropical cyclone formation. Recent work has also shown that the SAL can impact drought in the Caribbean. This project will address the factors that lead to the development of drought in the Caribbean, with a specific focus on Puerto Rico. The societal impact of this project is significant because the Caribbean Islands rely heavily on regular precipitation to meet agricultural, ecological, and municipal water needs. The lead researcher is a founding member of the Caribbean drought resource group SECARIBE and will share research findings with local water managers and operational weather forecasters. There is also a significant education and outreach component to the project with a two-week intensive summer course, aerosol workshop, participation in the Ocean Commotion K-8 event, and development of an interest segment with a local television station.The goal of this project is to address the question of how Saharan dust affects water stress in the insular Caribbean region. This project will pioneer three major innovations: (1) Develop a multi-decade dataset of SAL events and their morphological behavior; (2) Assess the morphological behavior in (1) as a function of the embedded dust load; and (3) Determine evaporative demand in the SAL destination region as a function of the dust load. Whereas previous research expressly considers dust as a rainfall suppressant, this is the first effort to extend the dust-warming effect to surface drought dynamics via evaporative demand. This project will use climatological analyses and numerical modeling using WRF-Chem to address three main hypotheses: 1) SALs are more frequent and/or stronger during drought years in the Caribbean, 2) Suspended dust within the SAL actively influences SAL evolution across the Atlantic, and 3) Dust-driven warming increases near-SAL evaporative demand, promoting flash drought.This project is jointly funded by Physical and Dynamic Meteorology, the Established Program to Stimulate Competitive Research (EPSCoR), and Climate and Large-scale Dynamics.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.