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| Rembauville, M.; Salter, I.; Leblond, N.; Gueneugues, A.; Blain, S.. |
| A sediment trap moored in the naturally iron-fertilized Kerguelen Plateau in the Southern Ocean provided an annual record of particulate organic carbon and nitrogen fluxes at 289 m. At the trap deployment depth, current speeds were typically low (similar to 10 cm s(-1)) and primarily tidal-driven (M2 tidal component). Although advection was weak, the sediment trap may have been subject to hydrodynamical and biological (swimmer feeding on trap funnel) biases. Particulate organic carbon (POC) flux was generally low (< 0.5 mmol m(-2) d(-1)), although two episodic export events (< 14 days) of 1.5 mmol m(-2) d(-1) were recorded. These increases in flux occurred with a 1-month time lag from peaks in surface chlorophyll and together accounted for... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00295/40578/39496.pdf |
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| Crombet, Y.; Leblanc, K.; Queguiner, B.; Moutin, T.; Rimmelin, P.; Ras, J.; Claustre, H.; Leblond, N.; Oriol, L.; Pujo-pay, M.. |
| The silicon biogeochemical cycle has been studied in the Mediterranean Sea during late summer/early autumn 1999 and summer 2008. The distribution of nutrients, particulate carbon and silicon, fucoxanthin (Fuco), and total chlorophyll-a (TChl-a) were investigated along an eastward gradient of oligotrophy during two cruises (PROSOPE and BOUM) encompassing the entire Mediterranean Sea during the stratified period. At both seasons, surface waters were depleted in nutrients and the nutriclines gradually deepened towards the East, the phosphacline being the deepest in the easternmost Levantine basin. Following the nutriclines, parallel deep maxima of biogenic silica (DSM), fucoxanthin (DFM) and TChl-a (DCM) were evidenced during both seasons with maximal... |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24393/22421.pdf |
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| Berthelot, H; Moutin, T.; L'Helguen, S.; Leblanc, K.; Helias, S.; Grosso, O.; Leblond, N.; Charriere, B.; Bonnet, S.. |
| In the oligotrophic ocean characterized by nitrate (NO3-) depletion in surface waters, dinitrogen (N-2) fixation and dissolved organic nitrogen (DON) can represent significant nitrogen (N) sources for the ecosystem. In this study, we deployed large in situ mesocosms in New Caledonia in order to investigate (1) the contribution of N-2 fixation and DON use to primary production (PP) and particle export and (2) the fate of the freshly produced particulate organic N (PON), i.e., whether it is preferentially accumulated and recycled in the water column or exported out of the system. The mesocosms were fertilized with phosphate (PO43-) in order to prevent phosphorus (P) limitation and promote N-2 fixation. The diazotrophic community was dominated by... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38672/73173.pdf |
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| Ternon, E.; Guieu, C.; Loye-pilot, M. -d.; Leblond, N.; Bosc, E.; Gasser, B.; Miquel, J. -c.; Martin, J.. |
| Simultaneous measurements of atmospheric deposition and of sinking particles at 200 and 1000 m depth, were performed in the Ligurian Sea (North-Western Mediterranean) between 2003 and 2007, along with phytoplanktonic activity derived from satellite images. Atmospheric deposition of Saharan dust particles was very irregular and confirmed the importance of sporadic high magnitude events over the annual average (11.4 g m(-2) yr(-1) for the 4 years). The average marine total mass flux was 31 g m(-2) yr(-1), the larger fraction being the lithogenic one (similar to 37%). The marine total mass flux displayed a seasonal pattern with a maximum in winter, occurring before the onset of the spring bloom. The highest POC fluxes did not occur during the spring bloom nor... |
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| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00309/42028/41326.pdf |
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