RUI: Collaborative Research: How does changing glacial coverage affect the transport and fate of DOM and nutrients in coastal watersheds on the Gulf of Alaska?

沿着阿拉斯加湾（果阿）的冰川变薄率通常高达6-8米yr-1。这种快速的冰川衰退对沿海流域水文和地球化学有重要影响，因为冰川冰的损失减少了水文储存，并通过使新的土地暴露于初级演替过程而大大改变了流域土地覆盖。冰川消退后陆地和水生生态系统的生态发展已被广泛探讨，但很少有研究土地覆盖的变化将如何改变物质输送到河流网络和通过河流网络到沿海河口。 该项目将通过评估冰川衰退如何改变阿拉斯加东南部沿海流域的水文和地球化学过程来填补这一关键的知识空白。 特别是，我们的研究将全面了解河流营养物质和溶解有机物（DOM）的物种形成，命运和运输将如何被持续的冰川退缩所改变。 每周和风暴采样与连续排放测量相结合，将提供成对的冰川和非冰川流域之间的养分和DOM产量的第一个详细和完整的比较。对流量、氧气、温度和浊度的连续测量将用于量化冰川融水对水文和物理参数的影响。实验方法（实验室和现场规模）结合纵向调查和流示踪剂将被用来阐明营养物质和DOM在下游运输的命运。最后，纵向天气和源采样也将用于访问的营养物质和碳流的主要景观来源。最终，项目研究结果将为果阿和其他冰川海岸地区的冰川衰退如何改变陆地到海洋的有机和无机营养物质通量提供新的见解。该项目将为阿拉斯加东南大学（UAS）的本科生提供实验室和实地研究机会。UAS是一所小型本科大学，阿拉斯加本地学生入学率较高（16%）。 此外，该项目将为一名研究生和一名博士后研究员提供培训。 本科生在这个研究项目的整合将提供一个框架，学生和研究人员合作调查气候，土地覆盖变化，水文和海洋地球化学过程在沿海流域之间的重要联系。 此外，该项目还将加强UAS科学家与门登霍尔冰川游客中心博物学家之间的现有伙伴关系，他们将共同努力，将项目成果纳入该中心的解释性展示中。 门登霍尔冰川是美国游客最多的冰川，每年接待30多万游客，因此提供了一个独特和有效的机会，开展与本项目调查结果有关的公共宣传和教育。最后，一位来自弗吉尼亚州蒙哥马利县的科学教育家将在一个夏天参加实地工作。科学教育家将把他们的经验带到当地的教室，并与同龄人分享他们的经验。

Glacier thinning rates along the Gulf of Alaska (GOA) are commonly as high as 6-8 m yr-1. This rapid glacial recession has important implications for coastal watershed hydrology and biogeochemistry because the loss of glacier ice decreases hydrologic storage and dramatically alters catchment landcover by exposing new land to the process of primary succession. The ecological development of terrestrial and aquatic ecosystems following deglaciation has been explored extensively, however there has been very little research on how landcover change will alter material delivery into and through the river network to coastal estuaries. This project will fill this critical knowledge gap by evaluating how glacial recession is altering hydrologic and biogeochemical processes in coastal watersheds in southeastern Alaska. In particular, our research will develop a comprehensive understanding of how the speciation, fate and transport of riverine nutrients and dissolved organic matter (DOM) will be altered by ongoing glacial retreat. Weekly and storm sampling combined with continuous discharge measurements will provide the first detailed and complete comparison of nutrient and DOM yields between paired glacial and non-glacial watersheds. Continuous measurements of discharge, oxygen, temperature and turbidity will be used to quantify the effects of glacial meltwater on hydrologic and physical parameters. Experimental approaches (laboratory and field-scale) combined with longitudinal surveys and stream tracers will be used to elucidate the fate of nutrients and DOM during downstream transport. Finally, longitudinal synoptics and source sampling will also be used to access the primary landscape sources of nutrients and carbon to the stream. Ultimately, project findings will provide new insights into how land-to-ocean fluxes of organic and inorganic nutrients are being altered by glacial recession along the GOA and in other glaciated coastal regions.The project will provide laboratory and field research opportunities for undergraduates at the University of Alaska Southeast (UAS), a small, undergraduate university with a high (16%) enrollment of native Alaskan students. Additionally, the project will provide training for one graduate student and one post-doctoral researcher. The integration of undergraduate students in this research project will provide a framework for students and researchers to cooperatively investigate important linkages among climate, landcover change, and hydrological and biogeochemical processes in coastal watersheds. In addition, the project will strengthen an existing partnership between scientists at UAS and naturalists at the Mendenhall Glacier Visitor Center who will work collaboratively to incorporate project results into an interpretive display at the center. The Mendenhall Glacier is the most visited glacier in the United States and hosts over 300,000 visitors each year and thus provides a unique and effective opportunity for public outreach and education related to the findings of this project. Finally, a science educator from Montgomery County, VA will partake in field work during one of the summers. The science educator will bring their experience into the local classrooms and share their experience with their peers.