Where does desert dust originate? Geomorphic and climatic control on the evolution of dust sources in the Mojave Desert, USA.

沙漠本质上是多尘的环境，目前的许多文献和科学研究都断言，尽管干燥的湖床在沙漠景观中只占很小的比例，但它们是灰尘的主要来源。在美国西南部的莫哈韦沙漠东部，在大约1万年前的一次气候转变中，古老的湖泊沉积物促成了沙丘和尘埃的形成。然而，大量的尘埃堆积的年龄更年轻，这表明除了游乐场以外的地貌在过去一直是尘埃的重要来源。这项建议的总体目标有三个：1)利用新的风洞技术，即便携式现场风蚀实验室(PI-SWERL)，确定哪些沙漠地貌提供了沙尘源；2)利用现代沙尘源作为类比，预测过去哪些地貌曾产生沙尘，并通过比较沙尘成分和潜在来源的时间变化，确定沙源是否随时间发生了变化；以及3)利用光激发发光技术确定土壤灰尘中沙粒的年龄，以确定沙漠土壤中的沙尘记录是否对应于沙丘活动的年龄。通过这项研究，将了解更多关于沙漠环境中与粉尘排放有关的地貌和土壤性质的类型，以及这些来源可能如何随地貌过程和气候变化而变化的信息。从科学的角度来看，粉尘很重要，因为添加到土壤中的粉尘控制着土壤的形成、土壤水文、景观演变和沙漠植物的生态功能。粉尘的产生是一个与能见度、安全和健康问题有关的社会问题。这项研究的更广泛影响包括与其他大学和研究人员的合作，继续开发年龄控制和风蚀技术和技术，以及将获得宝贵的实地和科学经验的大学生的支持。这项研究的结果将在一次重要会议上公布，发表在同行评议的科学期刊上，并提供给城市/道路规划者以及公园和娱乐区管理者使用。

Deserts are by nature dusty environments, and much of the current literature and scientific research has asserted that dry lake beds, or playas, are the major source of dust despite the fact that they make up a very small proportion of the desert landscape. In the eastern Mojave Desert, southwestern United States, ancient lake sediments contributed to the formation of sand dunes and dust during a climatic transition about 10,000 years ago. However, a large amount of dust accumulations are younger in age, suggesting that landforms other than playas have been significant sources of dust in the past. The overall goal of this proposal is three-fold: 1) determine which desert landforms provide sources of dust by using new wind tunnel technology, the Portable In Situ Wind Erosion Lab (PI-SWERL), 2) determine if the dust sources have changed over time by using modern dust sources as analogs to predict which landforms emitted dust in the past, and by comparing temporal changes in the composition of dust and potential sources, and 3) determine if the record of dust in desert soils corresponds to the age of sand dune activity, using optically stimulated luminescence technology to determine the ages of sand grains within the soil dust. From this research, more information will be learned regarding the types of landforms and soil properties associated with dust emissions in desert environments, and how these sources might change in response to geomorphic processes and climate change. Dust is important from a scientific standpoint because dust additions to soils control soil formation, soil hydrology, landscape evolution, and the ecologic function of desert plants. Dust generation is a societal concern related to visibility, safety, and health issues. Broader impacts of this research include collaboration with other universities and researchers, continued development of age control and wind erosion technologies and techniques, and the support of university students who will gain valuable field and scientific experience. The results of this research will be presented at a major conference, published in peer-reviewed scientific journals, and provided to city/road planners and park and recreational area managers for their use.