Granular Electrification in Aeolian Sand Transport: Paradox or Enigma?

风沙是许多环境中众所周知的自然危害。流沙威胁着人类住区和基础设施，增加了粉尘排放，带来一系列人类健康和环境退化问题。不太了解的是由输沙引起的静电的产生。感应电荷可能足够强，以增加灰尘的产生，改变沉积物的传输速率，导致闪络和击穿的传输线路，或中断信号传输。该项目旨在首次测量自然环境中颗粒电气化的细节，并利用这些数据开发更好的电气化运输模型。这一成果有助于理解和预测沙丘等常见沉积风成体系的演化和迁移。对气候变化影响的预测包括荒漠化加剧和目前稳定的草原重新流动，如内布拉斯加州沙丘。更好的沙输运模型将是规划适应以管理未来沙漂移的宝贵工具。该项目通过发展一个涉及六个国家的国际研究合作网络和培训未来的科学家，包括一名女博士，为科学基础设施作出贡献。学生和几个MS。和本科生。该项目与科学教育中心、大学大气研究公司合作，为STEM培训开发教材和视频;与亚拉巴马科学运动计划合作，为培训教师举办关于地球和空间科学的研讨会;并提供简单的沙子运输和电气化基础课程演示。该项目将开展一项全面的实地活动，以阐明颗粒带电对风成沙输运率的影响，并利用其结果开发更好的沙输运模型，可应用于当前和未来的陆地和地外环境。将获得数据来描述风速;沙子运输;颗粒、大气和表面电荷;跃移强度;沙子大小和含水量;以及空气温度和相对湿度。将使用多元回归和其他统计方法对数据进行分析，以量化电气化影响的大小和方向。实验设计将确保所产生的数据集将具有最高的质量标准，并达到很少（如果有的话）达到的详细程度。成功将导致更强大的传输率模型，包括颗粒电气化条款，从而提高理解流沙，沙丘建设，风蚀和粉尘生成的动力学能力。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Wind-blown sand is a well known, natural hazard in many environments. Drifting sand threatens settlements and infrastructure, and enhances dust emissions, with a suite of consequential human health and environmental degradation issues. Less understood is the generation of static electricity caused by sand transport. The induced electric charges may be strong enough to enhance dust generation, alter sediment transport rates; cause flashover and breakdown in transmission lines; or interrupt signal transmission. This project aims to measure, for the first time, details of granular electrification in a natural environment and to use the data to develop better transport models that account for electrification. Success here contributes to understanding and predicting the evolution and migration of common sedimentary aeolian systems such as dune fields. Projections of the impacts of climate change include increased desertification and remobilization of currently stabilized grasslands, such as the Nebraska Sandhills. Better sand transport models will be valuable tools for planning adaptations to manage future sand drift. The project contributes to the infrastructure of science by developing an international research collaboration network involving six countries and training future scientists, including a female Ph.D. student and several M.S. and undergraduate students. The project partners with the Center for Science Education, University Corporation for Atmospheric Research to develop teaching materials and videos for STEM training; work with the Alabama Science in Motion program to conduct workshops for training teachers about Earth and Space science; and deliver simple class demonstrations of fundamentals of sand transport and electrification. This project will conduct a comprehensive field campaign to elucidate the influence of granular electrification on aeolian sand transport rates and use the results to develop better sand transport models that can be applied to current and future terrestrial and extraterrestrial environments. Data will be obtained to describe wind speeds; sand transport; granular, atmospheric, and surficial electrical charges; saltation intensity; sand size and moisture content; and air temperature and relative humidity. The data will be analyzed with multiple regression and other statistical methods to quantify the magnitude and direction of electrification effects. The experimental design will ensure that the resulting data set will be of the highest standards of quality and at a level of detail seldom (if ever) achieved. Success will lead to more robust transport rates models that include granular electrification terms, leading to enhanced ability to understand the dynamics of sand drift, dune building, aeolian abrasion, and dust generation.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.