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| Cossa, Daniel; Heimbuerger, Lars-eric; Lannuzel, Delphine; Rintoul, Stephen R.; Butler, Edward C. V.; Bowie, Andrew R.; Averty, Bernard; Watson, Roslyn J.; Remenyi, Tomas. |
| We present here the first mercury speciation study in the water column of the Southern Ocean, using a high-resolution south-to-north section (27 stations from 65.50 degrees S to 44.00 degrees S) with up to 15 depths (0-4440 m) between Antarctica and Tasmania (Australia) along the 140 degrees E meridian. In addition, in order to explore the role of sea ice in Hg cycling, a study of mercury speciation in the "snow-sea ice-seawater" continuum was conducted at a coastal site, near the Australian Casey station (66.40 degrees S; 101.14 degrees E). In the open ocean waters, total Hg (Hg(T)) concentrations varied from 0.63 to 2.76 pmol L(-1) with "transient-type" vertical profiles and a latitudinal distribution suggesting an atmospheric mercury source south of the... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15221/12677.pdf |
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| Louropoulou, Evangelia; Gledhill, Martha; Browningi, Thomas J.; Desai, Dhwani K.; Barraqueta, Jan-lukas Menzel; Tonnard, Manon; Sarthou, Geraldine; Planquette, Helene; Bowie, Andrew R.; Schmitz, Ruth A.; Laroche, Julie; Achterberg, Eric P.. |
| Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (< 1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (> 0.7 mu m) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median =... |
| Tipo: Text |
Palavras-chave: Heme b; North Atlantic; Phytoplankton; Diatoms; Iron; Limitation; GEOTRACES; GEOVIDE. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00508/61940/66029.pdf |
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| Grand, Maxime M.; Laes, Agathe; Fietz, Susanne; Resing, Joseph A.; Obata, Hajime; Luther, George W.; Tagliabue, Alessandro; Achterberg, Eric P.; Middag, Rob; Tovar-sánchez, Antonio; Bowie, Andrew R.. |
| Trace metal micronutrients are integral to the functioning of marine ecosystems and the export of particulate carbon to the deep ocean. Although much progress has been made in mapping the distributions of metal micronutrients throughout the ocean over the last 30 years, there remain information gaps, most notable during seasonal transitions and in remote regions. The next challenge is to develop in situ sensing technologies necessary to capture the spatial and temporal variabilities of micronutrients characterized with short residence times, highly variable source terms, and sub-nanomolar concentrations in open ocean settings. Such an effort will allow investigation of the biogeochemical processes at the necessary resolution to constrain fluxes, residence... |
| Tipo: Text |
Palavras-chave: Trace metals; Micronutrients; In situ chemical analyzers; In situ sensors; GEOTRACES; OceanObs'19; Ocean observing time series. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00482/59337/62116.pdf |
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| Tonnard, Manon; Planquette, Hélène; Bowie, Andrew R.; Van Der Merwe, Pier; Gallinari, Morgane; Desprez De Gésincourt, Floriane; Germain, Yoan; Gourain, Arthur; Benetti, Marion; Reverdin, Gilles; Tréguer, Paul; Boutorh, Julia; Cheize, Marie; Menzel Barraqueta, Jan-lukas; Pereira-contreira, Leonardo; Shelley, Rachel; Lherminier, Pascale; Sarthou, Géraldine. |
| Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00441/55233/56714.pdf |
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| Henley, Sian F.; Cavan, Emma L.; Fawcett, Sarah E.; Kerr, Rodrigo; Monteiro, Thiago; Sherrell, Robert M.; Bowie, Andrew R.; Boyd, Philip W.; Barnes, David K. A.; Schloss, Irene R.; Marshall, Tanya; Flynn, Raquel; Smith, Shantelle. |
| The Southern Ocean plays a critical role in regulating global climate as a major sink for atmospheric carbon dioxide (CO2), and in global ocean biogeochemistry by supplying nutrients to the global thermocline, thereby influencing global primary production and carbon export. Biogeochemical processes within the Southern Ocean regulate regional primary production and biological carbon uptake, primarily through iron supply, and support ecosystem functioning over a range of spatial and temporal scales. Here, we assimilate existing knowledge and present new data to examine the biogeochemical cycles of iron, carbon and major nutrients, their key drivers and their responses to, and roles in, contemporary climate and environmental change. Projected increases in... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Biogeochemistry; Primary production; Iron; Nutrients; Carbon; Ecosystem; Ocean acidification. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78831/81113.pdf |
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