Collaborative Research: Investigation of the fate and transport of dust-borne trace metals and solutes during snowmelt

合作研究：调查融雪过程中粉尘携带的痕量金属和溶质的去向摘要风尘为山区积雪提供了痕量金属和可溶盐，并对融雪期间的水质产生了潜在的负面影响。美国西部山区湖泊的沉积物记录表明，由于人类对沙漠土壤的干扰，沙尘沉积在过去150年里增加了五倍，由于气候变化，预计未来会有更多沙尘。然而，关于尘埃对山间溪流化学成分的影响，人们知之甚少。融雪溪流是美国西部饮用水的主要来源。普罗沃河就是一个很好的例子，为犹他州超过50%的居民提供了水。本项目调查乌伊塔山上游普罗沃河流域积雪融化过程中粉尘对水质的影响。评估粉尘对山区积雪的贡献，以及演示融雪过程中微量金属和盐分的运输路径，可能会延伸到西部山区和美国以外的其他接受大量粉尘输入的山区，包括安第斯山脉、喜马拉雅山脉和欧洲阿尔卑斯山。该项目在基于探究的实地考察中为K-16学生提供外展机会，促进犹他州三大研究机构(犹他大学、犹他州立大学和杨百翰大学)的研究生跨校园合作，并通过让妇女和少数族裔参与来扩大代表不足群体的参与。该项目通过详细的现场采样和综合分析，调查了融雪建筑过程中粉尘衍生的痕量金属和溶质的去向和迁移。用同位素示踪剂(如锶、硼、硫、氧和氢)和混合分析对融雪过程中尘埃对水系溶质收支的贡献进行了量化。通过应用几种新的分析方法，研究了有机质促进的痕量金属从积雪到溪流的运输的作用。定量了粉尘沉积的空间非均质性，并通过连续淋溶实验表征了粉尘中痕量金属的有效性。普罗沃河流域是研究尘埃对水化学影响的理想地点，因为它的底层是相对简单的硅质碎屑基岩，可以清楚地观测到外来尘埃，而且由美国国家科学基金会资助的创新城市转型和干旱地区水文可持续发展(IUTAH)天文台的大气和水生监测站配备了良好的仪器。地质背景和广泛的仪器设备为探索融雪期间尘埃沉积对水系化学的影响提供了前所未有的机会。

Collaborative Research: Investigation of the fate of dust-borne trace metals and solutes during snowmeltAbstractWind-blown dust contributes trace metals and soluble salts to mountain snowpack, with potential negative impacts on water quality during snowmelt. Sediment records from mountain lakes in the western U.S. suggest that dust deposition has increased five-fold over the past 150 years due to human disturbance of desert soils, with more dust expected in the future due to climate change. Little is known, however, concerning the impacts of dust on the chemistry of mountain streams. Snowmelt-fed streams are a primary source of drinking water in the western U.S. The Provo River is a prime example of this, supplying water to over 50% of the residents of Utah. This project investigates the effects of dust on water quality during snowmelt in the upper Provo River watershed in the Uinta Mountains. Assessment of dust contributions to mountain snowpack and demonstration of pathways of trace metal and salt transport during snowmelt have the potential to extend across the Intermountain West and beyond the U.S. to other mountainous areas receiving substantial dust input, including the Andes, Himalayas, and European Alps. This project provides K-16 student outreach opportunities during inquiry-based field exercises, fosters cross-campus collaborations for graduate students at Utah's three major research institutions (University of Utah, Utah State University, and Brigham Young University), and broadens participation of underrepresented groups by involving women and minorities. The project investigates the fate and transport of dust-derived trace metals and solutes during snowmelt building from detailed field sampling and comprehensive analyses. Dust contributions to stream solute budgets during snowmelt are quantified with isotopic tracers (e.g., strontium, boron, sulfur, oxygen and hydrogen) and mixing analyses. The role of organic matter-facilitated trace-metal transport from snowpack to streams is examined through application of several novel analytical methods. Spatial heterogeneity in dust deposition is quantified, and the availability of trace metals in dust is characterized via sequential leaching experiments. The Provo River watershed is an ideal location for investigating impacts of dust on water chemistry because it is underlain by relatively simple siliciclastic bedrock that permits clear observations of exogenous dust and is well instrumented with atmospheric and aquatic monitoring stations from the Innovation Urban Transitions and Aridregion Hydro-sustainability (iUTAH) observatory funded by NSF. The geological setting and extensive instrumentation provide an unprecedented opportunity to explore the impacts of dust deposition on stream chemistry during snowmelt.