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Biogeochemical Tracers in Arctic Rivers: Linking the Pan-Arctic Watershed to the Arctic Ocean

PI: Bruce J. Peterson Co: Robert M. Holmes Institution: Marine Biological Lab

Abstract

A 5-year project is proposed in which selected parameters focusing on tracers of river water will be measured in the largest 6 rivers that drain the watershed of the Arctic Ocean: the Yenisey, Lena, Ob', Mackenzie, Yukon, and Kolyma. Tracers to be measured include H218O, barium, organic matter, alkalinity, and nutrients. Sampling will be conducted during the high flow season in Years 1 and 4 and during all seasons in Years 2 and 3. Synthesis and modeling will occur throughout the 5-year project. Samples will be collected near the mouths of the rivers (but above tidal influence) in order to get fully integrated watershed signals and the most relevant freshwater end member values for oceanographic tracking. To investigate transport pathways of river waters through the Arctic Ocean, newly defined end member values will be examined in the context of existing and growing oceanographic tracer databases. To study watershed sources, tracers will be examined in the context of geomorphology, land cover, and hydrology models. The proposed work will also generate a synoptic pan-arctic database on river biogeochemistry for comparison with past and future data in trend analyses. A collaborative network of expertise to successfully sample the 6 largest arctic rivers was assembled. Scientists from 4 nations are involved, including representatives of agencies responsible for water quality monitoring in the Russian, Canadian, and US Arctic. The research group is also in a strong position to analyze and synthesize information on river tracer fluxes into and through the Arctic Ocean at the pan-Arctic scale because of the diverse expertise brought to the project by hydrologists, biogeochemists, and oceanographers. Outreach will involve participation of high school students living in villages near the study sites. Under the supervision of local teachers or researchers, these students will collect water samples from their rivers. They will perform basic analyses such as temperature, pH, and conductivity. Participating students will also be active in exchange of data via the web where available. Scientists from the research group will visit the students and discuss the project, present lectures to their classes, and involve the students in as many aspects of the project as possible.