Overview of the dissolved iron, manganese and aluminium distributions along the North Atlantic GEOTRACES GA03 section

Three trace elements distributions (iron, manganese and aluminium) help to constrain the sources of chemical elements in the North Atlantic Ocean. Atmospheric, Mediterranean Sea and margin inputs are confirmed while the importance of the hydrothermal venting is revealed.

Hatta, Measures and co-workers (2014, see references below) established an overview of dissolved iron, manganese and aluminium (dFe, dMn and dAl respectively) distributions (see figures below) along the North Atlantic GA03 GEOTRACES section. Elevated dFe concentrations correlate with elevated dAl ones in the surface waters of the subtropical gyre, confirming a substantial atmospheric source for both tracers. But this is not the case for dMn. Sedimentary inputs from margins concern the three tracers but are mostly revealed from elevated dMn signals in the eastern basin, particularly near the African coast and in the western basin, along the advective flow path of the Upper Labrador Sea Water.

The most striking results are found in the neutrally buoyant hydrothermal plume sampled over the Mid-Atlantic Ridge. There the largest dFe anomaly (~68 nM), a dMn anomaly (up to ~33 nM) and large amount of Al (up to 40nM) are detected, with signals visible for ~500 km to the west of the ridge.

14 hatta measures final l

Figure. Distribution of dissolved iron (upper), aluminiun (middle) and manganese (lower) along the North Atlantic GA03 GEOTRACES section. Warm colours (red, orange, etc.) indicate high concentrations. Click here to view the figure larger.

 

References :

Hatta, M., Measures, C. I., Wu, J., Roshan, S., Fitzsimmons, J. N., Sedwick, P., & Morton, P. (2014). An overview of dissolved Fe and Mn Distributions during the 2010–2011 U.S. GEOTRACES north Atlantic Cruises: GEOTRACES GA03. Deep Sea Research Part II: Topical Studies in Oceanography, In Press. doi:10.1016/j.dsr2.2014.07.005 Click here to view the paper.

Measures, C., Hatta, M., Fitzsimmons, J., & Morton, P. (2014). Dissolved Al in the zonal N Atlantic section of the US GEOTRACES 2010/2011 cruises and the importance of Hydrothermal inputs. Deep Sea Research Part II: Topical Studies in Oceanography, In Press. doi:10.1016/j.dsr2.2014.07.006 Click here to view the paper.

Latest highlights

Science Highlights

Spatial and temporal variability of bioactive trace metals, speciation and organic metal-binding ligands in the eastern Gulf of Mexico

Mellett and Buck present the concentrations of bioactive trace metals (Fe, Cu, Mn, Zn, Co, Ni, Cd, and Pb), Fe-and Cu-binding organic ligands, and electroactive Fe-binding humic substances in the eastern Gulf of Mexico.

03.03.2021

Science Highlights

Thorium-Protactinium fate across the tropical Atlantic Ocean: what reveals the water column-sediment coupling

Twenty seawater profiles and twenty core-top 231-protactinium and 230-thorium analyses were realised by Ng and colleagues along five depth transects across the northern tropical Atlantic open ocean.

18.01.2021

Science Highlights

Constraining Oceanic Copper Cycling through Artificial Intelligence and Ocean Circulation Inverse Model

Using available observations of dissolved copper, artificial neural networks, and an ocean circulation inverse model, authors calculated a global estimate of the 3-dimensional distribution and cycling of dissolved copper in the ocean.

15.01.2021

Science Highlights

Particulate rare earth elements distributions, processes and characterisation of nepheloids in the North Atlantic

Lagarde et al. realised the first basin scale section of particulate rare earth elements concentrations across the North Atlantic Ocean.

06.01.2021

Rechercher