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

这个研究项目的重点是风对沙子的抬升，即所谓的跃移，以及天气和气候模型如何描述它。风沙有直接的影响，比如形成沙丘，但当沙粒撞击并喷出更细的沙粒时，也会产生二次影响。这些颗粒被称为矿物粉尘气溶胶，是全球颗粒物的主要来源之一，影响人类健康、天气、气候、生态系统、大气化学和水文循环。目前的数值模式将跃变视为一个均匀的过程，而研究表明，跃变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、精细模型（大涡模拟）和全球尺度（地球系统）模型的结合来改善跃迁过程的表现。这项工作将包括四个主要任务：1)将沙尘输送的间断性和强度与大气湍流联系起来；2)从天气和气候模式将大气湍流与大气边界层的整体特性联系起来；3)开发一种改进的沙尘排放参数化方法，用于解释湍流驱动的间断性；4)验证间断性在沙尘事件的时间和大小中起重要作用的假设。该项目更广泛的影响将包括社会和教育推广部分。该项目的成功完成将改进社区地球系统模式（CESM）和其他天气和气候模式，从而更准确地预报美国西南部和北非等多尘地区的天气和区域气候变化。两名研究生将在项目期间接受培训，这些学生将与主要研究人员和一名专业教育工作者合作开发一个基于风蚀和湍流的教育模块，以解决物理科学领域的一系列国家和州标准。这些模块将通过一个针对高中教师的研讨会和一个收集物理课程计划的网站进行传播。研究人员和研究生还将通过客座讲座和参与“收养物理学家”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.