Arctic – Atlantic Exchange of the Dissolved Micronutrients Iron, Manganese, Cobalt, Nickel, Copper and Zinc With a Focus on Fram Strait

• Published in: Global Biogeochemical Cycles
• Main Authors: Krisch, Stephan, Hopwood, Mark J., Roig, Stéphane, Gerringa, Loes J. A., Middag, Rob, Rutgers van der Loeff, Michiel M., Petrova, Mariia V., Lodeiro, Pablo, Colombo, Manuel, Cullen, Jay T., Jackson, Sarah L., Heimbürger‐Boavida, Lars‐Eric, Achterberg, Eric P., Hopwood, Mark J.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany, Roig, Stéphane; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany, Gerringa, Loes J. A.; 3 NIOZ Royal Netherlands Institute for Sea Research Den Burg The Netherlands, Middag, Rob; 3 NIOZ Royal Netherlands Institute for Sea Research Den Burg The Netherlands, Rutgers van der Loeff, Michiel M.; 4 Alfred‐Wegener‐Institute for Polar and Marine Research Bremerhaven Germany, Petrova, Mariia V.; 5 Aix Marseille Université CNRS/INSU Université de Toulon, IRD Mediterranean Institute of Oceanography (MIO) UM 110 Marseille France, Lodeiro, Pablo; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany, Colombo, Manuel; 7 Department of Earth, Ocean, and Atmospheric Sciences University of British Columbia Vancouver BC Canada, Cullen, Jay T.; 8 School of Earth and Ocean Sciences University of Victoria Victoria BC Canada, Jackson, Sarah L.; 8 School of Earth and Ocean Sciences University of Victoria Victoria BC Canada, Heimbürger‐Boavida, Lars‐Eric; 5 Aix Marseille Université CNRS/INSU Université de Toulon, IRD Mediterranean Institute of Oceanography (MIO) UM 110 Marseille France
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: ddc:551.9; Arctic Ocean; Fram Strait; trace elements; Arctic‐Atlantic micronutrient exchange; flux budget; GEOTRACES; Arctic; Barents Sea; Davis Strait; Nordic Seas; North Atlantic; Sea ice
• Online Access: https://doi.org/10.1029/2021GB007191; http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10231

The Arctic Ocean is considered a source of micronutrients to the Nordic Seas and the North Atlantic Ocean through the gateway of Fram Strait (FS). However, there is a paucity of trace element data from across the Arctic Ocean gateways, and so it remains unclear how Arctic and North Atlantic exchange shapes micronutrient availability in the two ocean basins. In 2015 and 2016, GEOTRACES cruises sampled the Barents Sea Opening (GN04, 2015) and FS (GN05, 2016) for dissolved iron (dFe), manganese (dMn), cobalt (dCo), nickel (dNi), copper (dCu) and zinc (dZn). Together with the most recent synopsis of Arctic‐Atlantic volume fluxes, the observed trace element distributions suggest that FS is the most important gateway for Arctic‐Atlantic dissolved micronutrient exchange as a consequence of Intermediate and Deep Water transport. Combining fluxes from FS and the Barents Sea Opening with estimates for Davis Strait (GN02, 2015) suggests an annual net southward flux of 2.7 ± 2.4 Gg·a−1 dFe, 0.3 ± 0.3 Gg·a−1 dCo, 15.0 ± 12.5 Gg·a−1 dNi and 14.2 ± 6.9 Gg·a−1 dCu from the Arctic toward the North Atlantic Ocean. Arctic‐Atlantic exchange of dMn and dZn were more balanced, with a net southbound flux of 2.8 ± 4.7 Gg·a−1 dMn and a net northbound flux of 3.0 ± 7.3 Gg·a−1 dZn. Our results suggest that ongoing changes to shelf inputs and sea ice dynamics in the Arctic, especially in Siberian shelf regions, affect micronutrient availability in FS and the high latitude North Atlantic Ocean. Plain Language Summary: Recent studies have proposed that the Arctic Ocean is a source of micronutrients such as dissolved iron (dFe), manganese (dMn), cobalt (dCo), nickel (dNi), copper (dCu) and zinc (dZn) to the North Atlantic Ocean. However, data at the Arctic Ocean gateways including Fram Strait and the Barents Sea Opening have been missing to date and so the extent of Arctic micronutrient transport toward the Atlantic Ocean remains unquantified. Here, we show that Fram Strait is the most important gateway for Arctic‐Atlantic micronutrient ...