Roshan and collaborators present new observations of dissolved iron and its physical speciation in the South Pacific
Jun / 10 / 2020
Iron
Mechanisms driving biological CO2 drawdown in the Subarctic Pacific unraveled
Nishioka and co-authors compiled comprehensive data sets of iron and macronutrients covering the whole subarctic Pacific…
Jun / 04 / 2020
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
The Colloidal Hourglass: North Atlantic Iron Distribution Controlled by Dynamic Colloidal Phase
K. Kunde and colleagues (2019, reference below) show that a highly dynamic colloidal iron phase in the upper ocean and at the seafloor boundary controls the distribution of dissolved iron at key sources and sinks across the subtropical North Atlantic Ocean, while the ocean interior is marked by an equilibrium partitioning between the soluble and […]
Feb / 07 / 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