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 […]

May / 15 / 2020

Loihi Seamount, hydrothermal Helium-3 and dissolved iron sources and their dispersion within the Pacific Ocean

As part of the GEOTRACES cruise GP15, Jenkins and co-workers (2020, see reference below) observed large water column anomalies in helium isotopes and trace metal concentrations above the Loihi Seamount (~19°N, 154°W) that extends along the GP15 track for hundreds of kilometers. Expanding their data with historical ones, they observe that the Loihi Helium-3 (3He) […]

May / 04 / 2020

Oceanic Margins as sources of lithogenic particulate and dissolved iron in the North Pacific Ocean

Three GEOTRACES Japanese cruises on board the R/V Hakuho Maru allowed establishing basin-scale and full-depth sectional distributions of total dissolvable iron (tdFe), dissolved iron (dFe), and labile particulate iron (lpFe=tdFe – dFe) in the North Pacific Ocean. Zheng and Sohrin (2019, see reference below) also discuss aluminum (Al) and manganese (Mn) data in this work. […]

Mar / 10 / 2020

Is the global primary production at it’s maximum rate?

Lauderdale and co-authors (2020, see reference below) are seriously questioning the paradigm establishing that marine phytoplankton growth is limited by iron on a global scale. Iron availability to marine microbes is facilitated by binding with organic molecules which, in turn, are produced by microbes. The authors hypothesize this forms a reinforcing cycle between biological activity […]

Feb / 25 / 2020

Can phytoplankton help us determine the bioavailability of iron in the world ocean?

Joint Science Highlight with US Ocean Carbon and Biogeochemistry (OCB). Iron (Fe) is a key element to life but in seawater it is present at extremely low concentrations. The scarcity of this important micronutrient limits phytoplankton growth in large swaths of the global ocean with consequences to the marine food-web and carbon cycling. Understanding the […]

Feb / 24 / 2020

Unprecedented iron delivery from the Congo River margin to the South Atlantic Gyre

The Congo River is the world’s second largest river by discharge volume and the only major river discharging into an eastern boundary region. Despite of its size, the Congo River plume and its influence on trace element cycles and ocean primary productivity is poorly constrained. During GEOTRACES cruise GA08, Vieira and co-workers (2020, see reference […]

Jan / 30 / 2020