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| Fonseca-batista, Debany; Dehairs, Frank; Riou, Virginie; Fripiat, Francois; Elskens, Marc; Deman, Florian; Brion, Natacha; Queroue, Fabien; Bode, Maya; Auel, Holger. |
| Euphotic layer dinitrogen (N-2) fixation and primary production (PP) were measured in the eastern Atlantic Ocean (38 degrees N-21 degrees S) using N-15(2) and C-13 bicarbonate tracer incubations. This region is influenced by Saharan dust deposition and waters with low nitrogen to phosphorus (N/P) ratios originating from the Subantarctic and the Benguela upwelling system. Depth-integrated rates of N-2 fixation in the north (0 degrees N-38 degrees N) ranged from 59 to 370 mu mol N m(-2) d(-1), with the maximal value at 19 degrees N under the influence of the northwest African upwelling. Diazotrophic activity in the south (0 degrees S-21 degrees S), though slightly lower, was surprisingly close to observations in the north, with values ranging from 47 to 119... |
| Tipo: Text |
Palavras-chave: Nitrogen fixation; Atlantic Ocean; Primary production. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00379/49009/49451.pdf |
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| Lemaitre, Nolwenn; Planchon, Frederic; Planquette, Helene; Dehairs, Frank; Fonseca-batista, Debany; Roukaerts, Arnout; Deman, Florian; Tang, Yi; Mariez, Clarisse; Sarthou, Geraldine. |
| In this study we report particulate organic carbon (POC) export fluxes for different biogeochemical basins in the North Atlantic as part of the GEOTRACES GA01 expedition (GEOVIDE, May–June 2014). Surface POC export fluxes were deduced by combining export fluxes of total Thorium-234 (234Th) with the ratio of POC to 234Th of sinking particles at the depth of export. Particles were collected in two size classes ( > 53 and 1–53µm) using in situ pumps and the large size fraction was considered representative of sinking material. Surface POC export fluxes revealed latitudinal variations between provinces, ranging from 1.4mmolm−2d−1 in the Irminger basin, where the bloom was close to its maximum, to 12mmolm−2d−1 near the Iberian Margin, where the bloom had... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00465/57664/59860.pdf |
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