The transpolar drift as a source of riverine and shelf-derived trace elements to the central Arctic Ocean

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Charette, Matthew A., Kipp, Lauren, Jensen, Laramie T., Dabrowski, Jessica S., Whitmore, Laura M., Fitzsimmons, Jessica N., Williford, Tatiana, Ulfsbo, Adam, Jones, Elizabeth M., Bundy, Randelle M., Vivancos, Sebastian M., Pahnke, Katharina, John, Seth G., Xiang, Yang, Hatta, Mariko, Petrova, Mariia V., Heimbürger, Lars-Eric, Bauch, Dorothea, Newton, Robert, Pasqualini, Angelica, Agather, Alison, Amon, Rainer M. W., Anderson, Robert F., Andersson, Per S., Benner, Ronald, Bowman, Katlin, Edwards, R. Lawrence, Gdaniec, Sandra, Gerringa, Loes J. A., González, Aridane G., Granskog, Mats A., Haley, Brian, Hammerschmidt, Chad R., Hansell, Dennis A., Henderson, Paul B., Kadko, David C., Kaiser, Karl, Laan, Patrick, Lam, Phoebe J., Lamborg, Carl H., Levier, Martin, Li, Xianglei, Margolin, Andrew R., Measures, Christopher I., Middag, Rob, Millero, Frank J., Moore, Willard S., Paffrath, Ronja, Planquette, Helene, Rabe, Benjamin
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2020
• Subjects: Arctic Ocean; Transpolar Drift; trace elements; carbon; nutrients; GEOTRACES]; Arctic; Central Basin; Fram Strait; Ice; laptev; North Atlantic; permafrost
• Online Access: https://hdl.handle.net/1912/26070

Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125(5), (2020): e2019JC015920, doi:10.1029/2019JC015920. A major surface circulation feature of the Arctic Ocean is the Transpolar Drift (TPD), a current that transports river‐influenced shelf water from the Laptev and East Siberian Seas toward the center of the basin and Fram Strait. In 2015, the international GEOTRACES program included a high‐resolution pan‐Arctic survey of carbon, nutrients, and a suite of trace elements and isotopes (TEIs). The cruises bisected the TPD at two locations in the central basin, which were defined by maxima in meteoric water and dissolved organic carbon concentrations that spanned 600 km horizontally and ~25–50 m vertically. Dissolved TEIs such as Fe, Co, Ni, Cu, Hg, Nd, and Th, which are generally particle‐reactive but can be complexed by organic matter, were observed at concentrations much higher than expected for the open ocean setting. Other trace element concentrations such as Al, V, Ga, and Pb were lower than expected due to scavenging over the productive East Siberian and Laptev shelf seas. Using a combination of radionuclide tracers and ice drift modeling, the transport rate for the core of the TPD was estimated at 0.9 ± 0.4 Sv (106 m3 s−1). This rate was used to derive the mass flux for TEIs that were enriched in the TPD, revealing the importance of lateral transport in supplying materials beneath the ice to the central Arctic Ocean and potentially to the North Atlantic Ocean via Fram Strait. Continued intensification of the Arctic hydrologic cycle and permafrost degradation will likely lead to an increase in the flux of TEIs into the Arctic Ocean. Funding for Arctic GEOTRACES was provided by the U.S. National Science Foundation, Swedish Research Council Formas, French Agence Nationale de la Recherche and LabexMER, ...