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

沙漠是一种多尘的环境，目前的许多文献和科学研究都认为，干燥的湖床或干盐湖是灰尘的主要来源，尽管它们在沙漠景观中所占的比例很小。在美国西南部的莫哈韦沙漠东部，在大约1万年前的气候转变期间，古老的湖泊沉积物促成了沙丘和灰尘的形成。然而，大量的灰尘积累的年龄较年轻，这表明在过去，除干盐湖以外的地形一直是灰尘的重要来源。该提案的总体目标有三个方面：1）通过使用新的风洞技术，便携式原位风蚀实验室，确定哪些沙漠地貌提供了灰尘来源（PI-SWERL），2）通过使用现代灰尘源作为模拟物来预测过去排放灰尘的地形，确定灰尘源是否随时间而变化，并通过比较沙尘成分和潜在来源的时间变化，以及3）确定沙漠土壤中沙尘记录是否与沙丘活动的年龄相对应，利用光释光技术测定土壤尘埃中沙粒的年龄。从这项研究中，将了解更多有关沙漠环境中与粉尘排放相关的地貌类型和土壤特性的信息，以及这些来源如何响应地貌过程和气候变化而发生变化。从科学的角度来看，灰尘是重要的，因为灰尘添加到土壤中控制土壤形成，土壤水文，景观演变和沙漠植物的生态功能。粉尘产生是一个与能见度、安全和健康问题相关的社会问题。这项研究的更广泛的影响包括与其他大学和研究人员的合作，年龄控制和风蚀技术和技术的持续发展，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个重要的会议上发表，发表在同行评审的科学期刊上，并提供给城市/道路规划者和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.