Long-range transport of iron via the Agulhas Current and counter-current: a boon for the phytoplankton
Authors establish that significant iron fertilisation via the Agulhas current explains the Indian Subantarctic blooms…
Southern Ocean
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…
The development of the modern Antarctic Circumpolar Current occurred much later than previously thought!
This study is challenging the belief that the onset of the Antarctic Circumpolar Current was solely triggered by the opening and deepening of Southern Ocean Gateways.
Challenging results on iron bioavailability in the Southern Ocean
Fourquez and co-authors conducted dissolved iron uptake experiments with Phaeocystis antarctica…
Protactinium-231 budget of the Atlantic sector of Southern Ocean
Levier and colleagues analysed dissolved and particulate protactinium-231 in samples collected in a section in the Southern Ocean…
Using machine learning to accurately simulate the oceanic barium distribution
Mete and colleagues used machine learning to predict the global distribution of oceanic barium…
Irradiance-normalized non-photochemical quenching (NPQ): a new proxy of iron stress for phytoplankton
Ryan-Keogh and his colleagues used NPQ to fingerprint the photo-physiological response of phytoplankton to their environment.
Confrontation of two models to constrain the hydrothermal iron contribution to the Southern Ocean export production
Tagliabue and his co-workers compare the hydrothermal dissolved iron simulated by both models.
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.
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 iron to open ocean anaemic ecosystems.
Unique winter dataset of particulate and dissolved cadmium in the Indian sector of the Southern Ocean
Cloete and collaborators analysed particulate and dissolved cadmium at 7 stations in austral winter along a North South section off South Africa.
Manganese: a surprising co-limiting factor of phytoplankton growth in the Southern Ocean
One of the main consequences of this work is that manganese should be included in ocean-climate models, more particularly to improve the accuracy of their predictions in this area.
Informative zinc isotopic fractionation in the Southern Ocean
Ellwood and co-workers (2020, see reference below) established the distribution of dissolved and particulate zinc (dZn and pZn respectively) and its isotopes in the Subantarctic Zone South of Tasmania. Concentration […]
Glacial erosion processes suspected to enhance the lability of particulate iron, with a strong influence on the biological demand in the subantarctic waters
As part of the GEOTRACES process study HEOBI (GIpr05) van der Merwe and co-workers (2019, see reference below) conducted a thorough characterization of the labile and refractory iron phases of the […]
Upwelled hydrothermal iron stimulates massive phytoplankton blooms in the Southern Ocean
Joint Science Highlight with US-Ocean Carbon & Biogeochemistry (US-OCB). In a recent study, Ardyna et al (2019, see reference below) combined observations of profiling floats with historical trace element data and […]
Glacial erosion processes suspected to enhance the lability of particulate iron, with a strong influence on the biological demand in the subantarctic waters
As part of the GEOTRACES process study HEOBI (GIpr05) van der Merwe and co-workers (2019, see reference below) conducted a thorough characterization of the labile and refractory iron phases of the […]
The causes of the 90-ppm glacial atmospheric CO2 drawdown still strongly debated
Joint Science Highlight with US-Ocean Carbon & Biogeochemistry (US-OCB). Using an observationally constrained earth system model, S. Khatiwala and co-workers (2019, see reference below) compare different processes that could lead […]
Local geologies imprint the Antarctic Bottom Water neodymium isotopic signatures
Dissolved neodymium (Nd) isotopes and concentrations were measured at six stations in the Australian sector of the Southern Ocean, targeting the study of the Adelie Land Bottom Water (ALBW), a […]
What constrains the hydrothermal dissolved iron isotopic signatures?
Assessing the processes leading to dissolved iron (dFe) isotope fractionation in a hydrothermal plume is a key question, because it allows a better characterization of this specific source of dFe […]
Dissolved iron isotopes reveal that distinct processes are controlling this micronutrient distribution in the ocean
Abadie and co-workers propose new dissolved iron concentration and isotopic composition distributions (DFe and ICFe respectively) along the Bonus-Goodhope IPY section (GIPY4), in the Atlantic sector of the Southern Ocean. […]
Neodymium isotopic signature of the Ross Sea Water characterized
The first seawater neodymium isotopic compositions (εNd) and neodymium concentrations [Nd] profiles across the South Pacific circum-Antarctic fronts have been published recently (Basak et al., 2015, see reference below). Thanks to […]
Seasonal iron supply in the Southern Ocean is dominated by winter mixing
An international team of researchers analysed the available dissolved iron data taken from all previous studies of the Southern Ocean, together with satellite images taken of the area, to quantify […]
Organic copper complexation may stabilise seawater stable copper isotopic composition
Three deep-sea profiles were produced for the analysis of copper (Cu) concentration, along a transect covering very different biogeochemical regions: the oligotrophic North Tasman Sea (30ºS), the Tasman Front (40°S) […]
A geochemical-physical coupled approach to study phytoplankton plume dynamics off the Crozet Islands (Southern Ocean)
Interaction of the currents with the sediments deposited on the margins of the Crozet Islands (Southern Ocean) contributes to the supply of iron and other micronutrients to marine waters. This […]
First full depth profiles of zinc isotopes in the ocean, thanks to IPY/GEOTRACES cruise (GIPY5)
Three major and original features are deduced from the first three full depth profiles of zinc measured by Zhao and co-workers (2014; see reference below) in the Southern Ocean: below 1000 […]
New data on oceanic rare earth elements concentrations and neodymium isotopic compositions
Early 2014 was favourable to the publication of new data of rare earth elements (REE) concentrations and neodymium (Nd) isotopic compositions in extreme areas of the ocean: the southern Atlantic […]
A global compilation of dissolved iron measurements: focus on distributions and processes in the Southern Ocean
A data synthesis effort recently compiled over 13,000 observations of dissolved iron concentrations that more than doubled the previous data compilation. A systematic analysis of the distribution of data in […]
New beautiful results on marine particle speciation, a challenge for the GEOTRACES community…
Advanced Light Source x-ray spectromicroscopy (XANES) allows a fine description of the marine Fe pool chemical speciation and mineralogy. This work describes diverse arrays of iron particles (20- 700 nm), […]
Results from the GEOTRACES cruise section GIPY11
An interesting comparison of data of dissolved barium (Ba) and data of dissolved aluminium (Al) and silicate (Si) collected onboard the GEOTRACES cruise GIPY11 (ARK-XXII/2 Polarstern expedition) is presented in […]
Recent and original results in the Southern Ocean on mercury speciation and cadmium isotopes
For the first time detailed mercury (Hg) speciation was determined along an Australia-Antarctic section (Cossa, et al., 2011) and cadmium (Cd) isotopes along a South Africa-Antarctic section (Abouchami W., et […]