Collaborative Research: NSFGEO-NERC: The Origin of Aeolian Dunes (TOAD)

风成沙丘占据了地球表面的10%，它们既存在于广阔的沙漠沙海中，也作为海岸防洪的重要天然屏障。尽管对成熟沙丘进行了广泛的研究，“风吹沙丘是如何形成的？”这个问题仍然没有答案，但它对于理解沙丘作为主要的地质单位是至关重要的，特别是考虑到它们在美国沙漠地区越来越多的出现，以及它们对水和植被供应的不利影响。这项研究将检查气流、表面特性、沙粒运输变化和河床形状之间的关键相互关系，这些关系是对新生沙丘如何形成的有意义理解的基础。该项目将促进美国、英国和纳米比亚之间的国际合作。它将制作有关沙漠景观和地貌学的公共教育材料，促进与美国和纳米比亚国家公园的伙伴关系，并向学生提供高质量的科学培训和实地经验。将在三个精心选择的已知沙丘发育的地点进行高分辨率的地表性质和床型变化的现场监测。补充的实验室实验将能够精确地描述非常接近模拟沙丘三维表面的流动特征，与现场数据集一起，将驱动计算机模型来测试沙丘在沙漠、海岸和其他行星的一系列环境条件下对不同控制的敏感性。总的来说，这种方法为理解一个主要陆地地貌系统的起源提供了一个克服长期停滞的机会。该小组将与美国大沙丘国家公园和纳米比亚纳米布-瑙克卢夫特国家公园的工作人员合作，制作可广泛获取的公众参与材料。在纳米比亚戈巴布举行的一个专门的影响讲习班上，该小组将向感兴趣的纳米比亚当地和国际代表展示项目成果，以及如何利用这些成果影响社会和经济问题。该项目将吸引纳米比亚的本科生和研究生，为他们提供宝贵的经验，激励他们从事科学事业。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Aeolian (wind-blown) sand dunes occupy 10% of the Earth's surface, both in vast desert sand seas and as important natural defenses against flooding along coasts. Despite extensive study of mature dunes, the question of "How do wind-blown dunes form?" remains unanswered, yet it is central to understanding dunes as major geological units, particularly given their increasing occurrence in desert regions of the United States and their adverse impact on water and vegetation supplies. This research will examine the key inter-relationships between airflow, surface properties, changes in sand transport and bedform shape that lie behind a meaningful understanding of how nascent dunes emerge. The project will promote international collaboration among the United States, the United Kingdom, and Namibia. It will generate public educational materials about desert landscapes and geomorphology, foster partnerships with National Parks in both the United States and Namibia, and provide quality scientific training and field experience to students.Field monitoring of surface properties and bedform change at high resolution will be performed at three carefully chosen locations of known dune development. Complementary laboratory experiments will enable accurate characterization of flow very close to the 3D surface of modelled dunes that, together with the field datasets, will drive a computer model to test the sensitivity of dune initiation and growth to different controls in a range of environmental conditions in deserts, coasts and on other planets. In concert, this approach represents an opportunity to overcome an enduring plateau for understanding the origins of one of the major terrestrial landform systems. The team will work with staff at Great Sand Dunes National Park in the United States and the Namib-Naukluft National Park in Namibia to create broadly accessible public engagement materials. At a dedicated impact workshop in Gobabeb, Namibia, the team will showcase to interested local Namibian and international delegates the project findings and how these findings could be used to influence societal and economic issues. The project will engage undergraduate and graduate students in Namibia and give them valuable experience that could inspire them to pursue careers in science.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.