Collaborative Research: From Turbulence to Weather and Climate: Unraveling the Multi-scale Nature of Dust and Sand Transport in the Atmospheric Boundary Layer

该研究项目的重点是风吹沙，称为跃移，以及天气和气候模型如何描绘它。 风沙有直接的影响，如形成沙丘，但也有二次影响，当沙粒碰撞和喷射更细的灰尘颗粒。 这些颗粒被称为矿物尘埃气溶胶，是全球颗粒物的主要贡献者之一，影响人类健康，天气，气候，生态系统，大气化学和水文循环。 目前的数值模型将跃移视为一个统一的过程，而研究表明，跃移实际上是由靠近地表的湍流风驱动的，并且是高度间歇性的。 研究人员计划通过理论，实地活动，精细尺度建模（大涡模拟）和全球尺度（地球系统）建模的结合来改善跳跃过程的表现。 这项工作将涉及四项主要任务：1）将沙尘输送的不稳定性和强度与大气湍流联系起来，2）将大气湍流与天气和气候模式的整体大气边界层特性联系起来，3）开发一种改进的沙尘排放参数化，以说明不稳定性驱动的不稳定性，以及4）检验不透明度在沙尘事件的时间和强度中起重要作用的假设。该项目的更广泛影响将包括社会和教育&外展组成部分。 该项目的成功完成将导致社区地球系统模型（CESM）和其他天气和气候模型的改进，这将导致对美国西南部和北非等多尘地区的天气和区域气候变化进行更准确的预测。 两名研究生将在项目期间接受培训，学生沿着与主要研究人员和专业教育工作者将合作开发一个基于风蚀和湍流的教育模块，该模块涉及一系列国家和国家标准。 这些单元将通过为高中教师举办的讲习班和收集物理课程计划的网站传播。 研究人员和研究生还将通过客座讲座和参与物理学家项目与高中生互动。

The focus of this research project is on the lifting of sand by the wind, known as saltation, and how it is portrayed by weather and climate models. Wind-blown sand has direct impacts, such as forming dunes, but also secondary impacts when the sand particles impact and eject much finer dust particles. These particles are known as mineral dust aerosols and are one of the major contributors to global particulate matter, which affects human health, weather, climate, ecosystems, atmospheric chemistry, and the hydrological cycle. Current numerical models treat saltation as a uniform process, when studies have shown that saltation is actually driven by turbulent winds close to the surface and is highly intermittent. The researchers plan to improve the representation of the saltation process through a combination of theory, field campaigns, fine-scale modeling (Large-Eddy Simulation) and global-scale (Earth System) modeling. The work will involve four main tasks: 1) Linking the intermittency and intensity of sand transport to atmospheric turbulence, 2) linking atmospheric turbulence to the overall atmospheric boundary layer properties from weather and climate models, 3) developing an improved dust emission parameterization that accounts for turbulence-drive intermittency, and 4) testing the hypothesis that intermittency plays an important role in the timing and magnitude of dust events.The broader impacts of the project will include societal and education & outreach components. A successful completion of the project will result in an improvement to the Community Earth System Model (CESM) and other weather and climate models which should result in more accurate forecasts of weather and regional climate changes in dusty regions such as the southwestern US and North Africa. Two graduate students will be trained during the project, and the students along with the lead researchers and a professional educator will collaboratively develop an educational module, based on wind erosion and turbulence, that addresses a range of national and state standards in the physical sciences. The modules will be disseminated via a workshop for high school teachers and through a website that collects physics-based lesson plans. The researchers and graduate students will also interact with high school students through guest lectures and participation in the Adopt-a-Physicist program.