Icebergs; a huge but highly variable source of iron to the ocean
Icebergs have been speculated to constitute one of the largest fluxes of iron (Fe) into the polar oceans since the 1930s and thus recent increases in ice discharge around the […]
Iron
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 […]
A new application of aerosol iron isotopes: tracing anthropogenic iron; an example of the North Atlantic Ocean
Conway and co-authors (2019, see reference below) present the first evidence that anthropogenic iron (Fe) from combustion sources is visible at the basin scale, using iron isotopic composition (δ56Fe) analysis […]
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 Scottish shelf break is not a significant source of iron to North Atlantic surface waters
A high resolution survey of the distribution of dissolved iron (dFe) over the Hebridean (Scottish) shelf break was conducted as part of the U.K. Shelf Sea Biogeochemistry programme, a GEOTRACES […]
Gulf stream eddies are fertilizing the Western Atlantic Ocean
Tim Conway and co-authors (2018, see reference below) show that Gulf Steam eddies can provide an extra supply of iron, and nutrients such as phosphate and nitrate to the iron-starved […]
When hydrothermal iron fertilizes the surface ocean in the Western Tropical South Pacific Ocean
For the first time, iron measurements in the Western Tropical South Pacific reveal that shallow hydrothermal inputs from the Tonga Arc region fertilize the euphotic waters of this vast region. […]
Labile particulate iron isotopic signatures trace hydrothermal and margin inputs down to the benthic layers in the Eastern Pacific Ocean
For the first time, labile and total particulate iron (pFe) isotopic signatures were measured along a full depth oceanographic section (more than 200 0.8-51 µm-sized particles) in the Eastern Pacific […]
Surface South Pacific ecosystems reflect the availability of the nutrients iron, nitrate and phosphate
Thanks to a high resolution section across the South Pacific (150°E-150°W, GEOTRACES GP13 cruise), Ellwood and co-workers (2018, see reference below) identify that the gradient of sources and fates of […]
Widespread nutrient co-limitation discovered on GEOTRACES cruise
Browning and co-workers (2017, see reference below) find that multiple nutrients must be supplied to stimulate phytoplankton growth on the southeast Atlantic GEOTRACES GA08 cruise. The paper has been published […]
Shelf sediment dissolved iron source via non-reductive dissolution in the Gulf of Alaska
Crusius and co-workers (2017, see reference below), reveal temporal and spatial variability in the sources of iron (Fe) to the northern Gulf of Alaska, based on data from cruises from […]
Low iron sulfide precipitation rate in hydrothermal fluids during the early stage of mixing
Waeles and co-authors (2017, see reference below) report for the first time on the dissolved-particulate partition of iron (Fe) after in situ filtration at the early stage of mixing of […]
Important external dissolved iron inputs, HNLC water formation and strong biological seasonality explained in the North Pacific Ocean
Subarctic Pacific is known as High Nutrient, Low Chlorophyll (HNLC) area, where phytoplankton growth is limited by dissolved iron (DFe) availability. The biological activity in the surface waters is also […]
What controls hydrothermal plume transport of iron over 4000 km in the deep Pacific Ocean?
The striking extension of the dissolved iron and manganese plumes over more than 4000 km from their hydrothermal sources along the US GEOTRACES East Pacific Zonal Transect (EPZT) cruise (GP16) has […]
Changing the paradigm on the oceanic iron cycle
Tagliabue and co-workers (2017, see reference below) discuss an extensive review on the recent findings on iron (Fe) cycle in the ocean. They figure out clearly that: Fe is 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 […]
Siderophores facilitate microbial adaptation to iron limitation in the eastern tropical Pacific Ocean
Siderophores are organic compounds secreted by microbes to facilitate iron uptake. Using new methods to characterize trace metal organic ligands in seawater, Boiteau and colleagues (2016, see reference below) measured […]
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. […]
Are the dissolved iron distributions well represented by the global ocean biogeochemistry models?
Alessandro Tagliabue and co-workers (2016, see reference below) have conducted the first intercomparison of 13 global ocean iron models against the latest datasets emerging from GEOTRACES. A large disparity in […]
An example of a fruitful international intercomparison
The reliability of the GEOTRACES data products including the eGEOTRACES Electronic Atlas is strongly related to the quality of the data acquired by the different laboratories contributing to this international effort. A […]
Important warning about the uncertainties affecting results of dissolved iron concentration measurements in seawater using flow-injection with chemiluminescence detection
Flow-Injection with Chemiluminescence (FI-CL) is a procedure commonly applied in the framework of the GEOTRACES cruises because of its portability and hence suitability for shipboard deployment. Following the Guide for […]
Metal contents of North Atlantic phytoplankton across environmental gradients
Twining and co-workers (2015, see reference below) provide the first direct measurements of metal quotas in phytoplankton from across the North Atlantic Ocean (US GEOTRACES GA03), known to be subjected […]
Do you know that coastal phytoplankton is able to adapt to iron limitation?
Oceanographers have long understood that phytoplankton in the open ocean tend to have lower iron (Fe) requirements and/or more strategies for obtaining Fe from the environment. Adding a new twist […]
Unexpected magnitude of the hydrothermal iron inputs in the deep Pacific
Data from the US GEOTRACES Eastern Pacific Zonal Transect (EPZT, GP16) demonstrate that lateral transport of hydrothermal iron, manganese and aluminium extends up to 4000 km west of the southern […]
How iron isotopes offer a new window on the oceanic biogeochemical cycling of iron
Two process studies (2008 and 2012) designed to study temporal changes in the biogeochemical cycling of iron (Fe), provide in situ results for dissolved and particulate Fe (DFe and PFe) […]
Iron isotopes in the Equatorial Pacific Ocean: when the dissolved phases are heavier than the particulate ones
A detailed study of the dissolved and particulate iron (Fe) concentrations and isotopes off the Papua New Guinea coast is proposed. Regarding the sources, iron isotopic composition (δ56Fe) values reveal […]
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 […]
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 distribution of dissolved iron in the West Atlantic Ocean
Iron (Fe) is an essential trace element for marine life. Extremely low Fe concentrations limit primary production and nitrogen fixation in large parts of the oceans and consequently influence ocean […]