Natural copper-binding ligands in the Arctic Ocean. The influence of the Transpolar Drift (GEOTRACES GN04) - Université de Bretagne Occidentale Access content directly
Journal Articles Frontiers in Marine Science Year : 2023

Natural copper-binding ligands in the Arctic Ocean. The influence of the Transpolar Drift (GEOTRACES GN04)

Abstract

The Arctic Ocean is a unique biogeochemical environment characterized by low salinity surface waters, extensive sea-ice coverage, high riverine inputs, large shelf extension and the long residence time of deep waters. These characteristics determine the distribution of dissolved bio-essential trace metals, such as copper (Cu), and the dissolved organic-binding ligands capable of complexing it. This work reports the concentrations and conditional stability constants of dissolved Cu-binding ligands (L Cu and log K cond Cu2+L ) measured in samples from the Polarstern (PS94) expedition, as part of the international GEOTRACES program (cruise GN04). Full-depth profile stations from the Barents Sea, Nansen Basin, Amundsen Basin and Makarov Basin were analysed by competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV). The basins and water masses presented a wide range of L Cu concentrations (range: 1.40 – 7.91 nM) and log K cond Cu2+L values (range: 13.83 – 16.01). The highest variability of Cu-binding ligand concentrations was observed in surface waters (≤200 m), and mean concentrations increased from the Barents Sea and Nansen Basin (2.15 ± 0.31 nM and 1.93 ± 0.35 nM, respectively) to the Amundsen (3.84 ± 1.69 nM) and Makarov Basins (4.40± 2.03 nM). The influence of the Transpolar Drift (TDP) flow path was observed in the Amundsen and Makarov Basins, especially on Cu-binding ligand concentrations (L Cu range: 3.96 – 7.91 nM). In contrast, deep waters (>200 m) showed no significant differences between basins and water masses in terms of L Cu concentrations (range: 1.45 – 2.78 nM) and log K cond Cu2+L (range: 14.02 – 15.46). The presence of strong Cu-binding ligands (log K cond Cu2+L >13) in surface waters stabilises the excess of dissolved copper (dCu) transported in the TPD and favours its export to the Fram Strait and Nordic Seas.

Domains

Oceanography
Fichier principal
Vignette du fichier
fmars-10-1306278.pdf (6.29 Mo) Télécharger le fichier
Origin Publisher files allowed on an open archive
Licence

Dates and versions

hal-04387955 , version 1 (18-01-2024)

Licence

Identifiers

Cite

Veronica Arnone, J. Magdalena Santana-Casiano, Melchor González-Dávila, Hélène Planquette, Géraldine Sarthou, et al.. Natural copper-binding ligands in the Arctic Ocean. The influence of the Transpolar Drift (GEOTRACES GN04). Frontiers in Marine Science, 2023, 10, ⟨10.3389/fmars.2023.1306278⟩. ⟨hal-04387955⟩
25 View
1 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More