When atmospheric dynamic controls the nutrient distributions in the ocean

Rainfall detection with satellites together with high-resolution data (~0.3°) for dissolved iron (DFe), aluminium (DAl), and inorganic phosphorus (DIP), confirm the existence of a sharp north–south biogeochemical boundary in the surface nutrient concentrations of the (sub)tropical Atlantic Ocean.

Wet deposition in the region of the intertropical convergence zone (ITCZ) acts as the major dissolved iron (DFe) source to surface waters. These variations of higher Fe inputs tied to the ITCZ movements drive a shift in the latitudinal distribution of N2 fixation and subsequent phosphate depletion in surface waters.

Thus, atmospheric dynamic is driving surface nutrient concentrations and microbial (diazotrophic) activity, which divide the (sub)tropical Atlantic into a high-phosphate, low-iron system in the south, and a low-phosphate, high-iron system in the north.

14 Schlosser

Figure: From the top to the bottom: Data from the AMT-17 (red) and D361 (green) cruises for satellite derived rainfall, surface DFe, surface DIP, and depth integrated N2 fixation (filled circles) and Trichodesmium spp. abundance (filled stars). Click here to view the figure larger.

Reference:

Schlosser, C., Klar, J. K., Wake, B. D., Snow, J. T., Honey, D. J., Woodward, E. M. S., Lohan, M. C., Achterberg, E.D., Moore, C. M. (2014). Seasonal ITCZ migration dynamically controls the location of the (sub)tropical Atlantic biogeochemical divide. Proceedings of the National Academy of Sciences of the United States of America, 111(4), 1438–42. doi:10.1073/pnas.1318670111.

Latest highlights

MOTES: a new facility designed for trace element sampling in seawater

Zhang and a group of engineers and researchers from Shanghai and Qingdao are presenting a modular trace element sampling facility.

A thorough estimate of the hydrothermal plumes on neodymium concentration and isotope oceanic cycles

Basak and co-workers investigated the influence of particulate matter on neodymium distributions in the Southern East Pacific Rise Hydrothermal Plume.

What are the drivers of the distributions of cadmium, nickel, zinc, copper and cobalt, manganese and aluminium in the Atlantic Ocean? Two papers are tackling this issue

Chen and co-authors reveal that the distributions of dissolved tracers at depth in the South Atlantic are predominantly controlled by the mixing of North Atlantic Deep Water and waters of Antarctic origin…

Disentangling the sources and transport of iron in the Southern Ocean using a water mass mixing model analysis

Traill and co-workers used an extended optimum multiparameter analysis water‐mass mixing model to determine the interplay between physical and biological processes, and sources/sinks driving dissolved iron distributions…

Rechercher