Pan-Arctic Trends in Terrestrial Dissolved Organic Matter from Optical Measurements ...

• Main Authors: Mann, Paul J., Spencer, Robert G. M., Hernes, Peter J., Six, Johan, Aiken, George R., Tank, Suzanne E., McClelland, James W., Butler, Kenna D., Dyda, Rachael Y, Holmes, Robert M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2016
• Subjects: Carbon cycle; Arctic; Lignin; Colored dissolved organic matter CDOM; Parallel factor analysis PARAFAC; DOC; Climate change; Hydrology; Arctic Ocean; permafrost
• Online Access: https://dx.doi.org/10.3929/ethz-b-000122688; http://hdl.handle.net/20.500.11850/122688

Climate change is causing extensive warming across Arctic regions resulting in permafrost degradation, alterations to regional hydrology and shifting amounts and composition of dissolved organic matter (DOM) transported by streams and rivers. Here, we characterize the DOM composition and optical properties of the six largest Arctic rivers draining into the Arctic Ocean to examine the ability of optical measurements to provide meaningful insights into terrigenous carbon export patterns and biogeochemical cycling. The chemical composition of aquatic DOM varied with season, spring months were typified by highest lignin phenol and dissolved organic carbon (DOC) concentrations with greater hydrophobic acid content, and lower proportions of hydrophilic compounds, relative to summer and winter months. Chromophoric DOM (CDOM) spectral slope (S_275–295) tracked seasonal shifts in DOM composition across river basins. Fluorescence and parallel factor analysis identified seven components across the six Arctic rivers. ... : Frontiers in Earth Science, 4 ...