Recent changes in the Arctic climate have dramatically impacted its hydrological cycle. Increased precipitation, river runoff, and permafrost thaw have been observed throughout the pan-Arctic region, contributing to an increased flux of freshwater and land-derived material to the ocean. The implications of these changes for the Arctic Ocean carbon cycle have yet to be fully quantified, as rivers draining thawing permafrost landscapes have received limited attention. These systems have the potential to deliver large amounts of labile carbon to the Arctic marine environment as warming continues. Assessing the impact of these changes in continuous permafrost regions of the high Arctic, such as the Canadian Arctic Archipelago (CAA), is particularly challenging as baseline geochemical data are sparse and our understanding of river-ocean carbon flux is limited.
Preliminary observations from a field campaign in 2014 suggest that the geochemical signatures of small northern rivers draining into the CAA differ from those of the major Arctic drainage basins that reach to latitudes much farther South. The predominance of permafrost in CAA systems may directly influence how much carbon is exported to the marine environment, suggesting land-ocean carbon fluxes in this region could be especially sensitive to ongoing climactic change. Expanding on the preliminary work conducted in 2014, the proposed project will take advantage of international collaborations to gain access to remote, understudied regions of the Canadian high Arctic during the summer of 2015. Data collected will contribute to a baseline data set of river geochemistry throughout the CAA, filling a gap in our knowledge of rivers draining exclusively continuous permafrost systems. In addition, samples collected throughout the CAA during both field programs will provide a unique opportunity to use radiocarbon age data to investigate questions about the delivery of presumably old, albeit labile, permafrost derived carbon to the Arctic marine environment. These data will provide baseline measurements against which to assess future change in this region and will form the basis of a future NSF proposal focused on the seasonal cycle of rivers in continuous permafrost systems.
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