EAR-PF: Accounting for turbulent effects to improve prediction of sand and dust transport by wind

罗利马丁博士已被授予美国国家科学基金会地球科学博士后奖学金，在洛杉矶的加州大学开展研究和教育计划。 他将研究在自然沙漠和海滩环境中，沙的运输过程对湍流风的反应。 这种沙的输送形成沙丘，弹跳的沙对沙漠土壤的轰击产生沙尘暴。因此，重要的是要能够预测如何输沙率与风速的关系。 现有的理论提供了合理的预测沙运输在恒定的风，但这些预测下的湍流，快速波动的风条件下的自然环境的特点。 输沙率的变化滞后于近地面风速的变化，并反馈给近地面风速的变化。 通过实地观测支持的理论推理，该项目将量化这些波动的输沙和湍流风之间的复杂相互作用，最终目标是改善自然环境中输沙的预测。 该项目将自下而上进行，首先详细分析风沙相互作用，然后开发一个新的风沙模型，最后将该模型与自然环境中湍流风的描述联系起来。 风吹沙模型的开发和验证将以自然环境中风速和沙输运的高分辨率耦合测量为基础。 除了推进我们对沙漠和沿海环境形成的基本过程的理解外，这项工作还将为解决粉尘污染、海岸保护和农业土壤侵蚀等问题提供基础。 研究工作将与改善研究数据的公众可得性和可得性的举措相结合。 此外，还将通过为当地一所小学五年级学生制定地球科学实践项目，促进教育推广。

Dr. Raleigh Martin has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the University of California, Los Angeles. He will investigate the process of sand transport in response to turbulent winds in natural desert and beach environments. This sand transport forms sand dunes, and the bombardment of desert soils by bouncing sand produces dust storms. It is therefore important to be able to predict how the rate of sand transport is related to the speed of blowing wind. Existing theory provides reasonable predictions for sand transport under constant winds, but these predictions break down under the turbulent, rapidly-fluctuating wind conditions characteristic of natural environments. Changes in the rate of sand transport both lag and feed back onto changes in wind speed near the ground surface. Through theoretical reasoning supported by field observations, this project will quantify these complex interactions between fluctuating sand transport and turbulent winds, with the ultimate goal of improving predictions of sand transport in natural environments. The project will proceed from the bottom up, beginning with a detailed analysis of wind-sand interactions, leading into development of a new model for wind-blown sand, and culminating in a linkage of this model to descriptions of turbulent winds in natural environments. Development and validation of the wind-blown sand model will be based on coupled high-resolution measurements of wind speed and sand transport in natural environments. In addition to advancing our understanding of a basic process that shapes deserts and coastal environments, this work will provide the basis for addressing such issues as dust pollution, coastal protection, and agricultural soil erosion. Research efforts will be coupled to initiatives to improve the public availability and accessibility of research data. Furthermore, educational outreach will be fostered through development of hands-on earth science projects for fifth-grade students at a local elementary school.