The biogeochemical ventures of dissolved iron and manganese across the Arctic Ocean

The spatial distributions and biogeochemical cycling of dissolved Fe (dFe) and dissolved manganese (dMn) across the Arctic Ocean were established during summer and fall 2015. The Canadian GEOTRACES transect extended from the Canada Basin (CB) to the Labrador Sea (LS) via the Canadian Arctic Archipelago (CAA).

The surface, subsurface and deep water distributions for both metals are controlled by i) a large variety of processes and ii) a complex balance between sources and sink (river inputs in surface, advective transports and particle remineralization at depth). For example, the highest concentrations are measured in surface waters of the CAA and the CB because these regions are strongly influenced by river inputs. Contrastingly, in the highly productive Baffin Bay and Labrador Sea, the surface waters are markedly depleted in dFe and dMn while organic matter remineralization likely acts as a notable source of these elements to deep waters.

The figure below summarizes the complexity of the processes governing the fate of these elements in the Canadian Arctic Ocean.

Figure: a) Sampled stations for Fe and Mn during the Canadian Arctic GEOTRACES cruises, bathymetry and schematic of water circulation. b) Conceptual scheme displaying the concentrations and key processes (e.g. freshwater and sedimentary inputs, remineralization and scavenging removal) controlling the distributions of dissolved Fe and Mn in the Canadian Arctic Ocean.

Reference:

Colombo, M., Jackson, S. L., Cullen, J. T., & Orians, K. J. (2020). Dissolved iron and manganese in the Canadian Arctic Ocean: On the biogeochemical processes controlling their distributions. Geochimica et Cosmochimica Acta, 277, 150–174. DOI : https://doi.org/10.1016/j.gca.2020.03.012

Latest highlights

Science Highlights

Icebergs as sources of trace metals to the ocean: which impact?

Earth’s Ice Sheets are known to release significant quantities of lithogenic particles into the ocean every year, but how does this material affect trace metal availability in the ocean?

18.10.2021

Science Highlights

Microbial trace metal trafficking on marine particles

This study provides evidence for the processing of nine particulate trace metals in multiple manners by diverse microbial communities.

28.09.2021

Science Highlights

Volcanic emissions in the Southern Ocean: an efficient and unexpected source of iron for this remote area

This study suggests that volcanic emission can represent a significant source of bioavailable Fe to open ocean anaemic ecosystems.

20.09.2021

Science Highlights

Surprisingly heavy silicon isotopes in the surface and deep Arctic Ocean

Brzezinski and his colleagues report on a comprehensive study of the Arctic Ocean silicic acid concentrations and silicon isotopic composition…

14.09.2021

Rechercher