Understanding the Formation and Impacts of Warm-Season Trans-Atlantic African Dust Extremes

了解暖季跨大西洋非洲沙尘暴的形成和影响

• 批准号: 2227707
• 负责人: Bing Pu
• 金额: $ 36.07万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-15 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2227707&HistoricalAwards=false
• 关键词: Understanding; Formation; Impacts; Warm; Season

Mineral dust is emitted from dry and sparsely vegetated land surface by strong winds. In the atmosphere, dust particles modify radiation budget (via absorption, scattering, and emission) and interact with clouds, affecting a wide range of atmospheric processes. Each year a large amount of African dust is transported toward the tropical Atlantic Ocean. The westward transport pathway is regulated by atmospheric circulations and reaches its maximum northward position in boreal summer, when the hot, dry Saharan dust plumes often drift across the tropical North Atlantic into the Caribbean Basin and the United States. Extremely high dust loadings over the tropical North Atlantic are reported during some African dust outbreaks, along with high surface concentrations of dust over Puerto Rico and the southern United States that greatly degraded air quality in these downwind regions. While significant progress has been made toward characterizing trans-Atlantic African dust plumes, the causes and impacts of warm season extreme trans-Atlantic dust events are not fully understood. For instance, it is not clear why enhanced dust emissions in North Africa resulted in extremely high dust loading over the tropical Atlantic in some years but not others. This project will use satellite products, ground observations, and reanalysis to identify atmospheric circulation and land surface processes that are responsible for the extreme trans-Atlantic dust events and to examine how extreme dust plumes affect energy balance, clouds, and air quality along their westward transport pathway. The relative roles of dust emissions and transport in the formation of extreme trans-Atlantic African dust plumes will be examined in both observations and numerical experiments using a regional chemistry model. The proposed work includes scientific training for undergraduate and graduate students and educational activities through outreach events held by the University of Kansas Natural History Museum.North Africa is a prominent global source of atmospheric aerosols. Advanced knowledge of the variability, causes, and impacts of extreme trans-Atlantic African dust events will allow better understanding of the role of aerosols in the climate system, which is one of the major sources of uncertainty in evaluating current and predicting future climate change. The findings will benefit future studies of trans-continental dust events and air pollution forecast in the United States. The project will integrate research with education by engaging undergraduate students into the project and by incorporating research activities and findings into undergraduate and graduate courses. The project will support one graduate student and two undergraduate students to train the next generation of climate and atmospheric scientists. In addition, the investigators will participate in outreach events held by the University of Kansas Natural History Museum to share the findings with the public.This project is jointly funded by the Climate and Large-Scale Dynamics (CLD) and Physical and Dynamic Meteorology (PDM) programs in Division of Atmospheric and Geospace Sciences (AGS) as well as the Established Program to Stimulate Competitive Research (EPSCoR).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.

强风从干燥和稀疏的植被土地表面发出矿物灰尘。在大气中，灰尘颗粒会改变辐射预算（通过吸收，散射和发射）并与云相互作用，从而影响广泛的大气过程。每年，大量的非洲尘埃都被运送到热带大西洋。向西的运输途径受大气循环的调节，并在北方夏季达到最大的北向北向位置，当时炎热，干燥的撒哈拉尘羽经常越过热带北大西洋进入加勒比海盆地和美国。 据报道，在某些非洲尘埃爆发期间，北大西洋上的尘埃量极高，以及波多黎各和美国南部的高表面浓度，在这些下风地区大大退化了空气质量。尽管在表征跨大西洋非洲灰尘羽毛方面取得了重大进展，但尚未完全了解温暖季节极端跨大西洋尘埃事件的原因和影响。例如，尚不清楚为什么在北非增强的尘埃排放导致热带大西洋的尘埃载荷极高，而不是其他大西洋。该项目将使用卫星产品，地面观测和重新分析来识别负责极端跨大西洋尘埃事件的大气循环和地表过程运输路径。在观测和数值实验中，使用区域化学模型，将检查尘埃排放和运输在极端跨大西洋非洲灰尘羽状形成中的相对作用。拟议的工作包括通过堪萨斯大学自然历史博物馆举行的外展活动对本科和研究生的科学培训以及教育活动。非洲北非是全球大气气溶胶的杰出来源。对极端跨大西洋非洲尘埃事件的变异性，原因和影响的高级知识将使人们更好地了解气溶胶在气候系统中的作用，这是评估当前和预测未来气候变化的不确定性的主要不确定性之一。这些发现将使未来关于跨大陆尘埃事件和空气污染预测的研究受益。该项目将通过使本科生参与该项目，并将研究活动和发现纳入本科和研究生课程，将研究与教育融为一体。该项目将支持一名研究生和两名本科生培训下一代气候和大气科学家。此外，调查人员将参加堪萨斯大学自然历史博物馆举行的外展活动，以与公众分享调查结果。该项目由气候和大规模动态（CLD）以及物理和动态气象（PDM）共同资助。 ）大气和地理水平科学部（AGS）的计划以及启发竞争性研究的既定计划（EPSCOR）。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛影响的评论来评估值得支持的标准。