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| Registros recuperados: 21 | |
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| González,H E; Daneri,G; Menschel,E; Marchant,M; Pantoja,S; Hebbeln,D; Barria,C; Vera,R; Iriarte,J. |
| Vertical fluxes of particles have been estimated during the last decade in coastal and oceanic systems off central-southern Chile. Free-drifting, cylindrical sediment traps have been deployed below the mixing layer from coastal areas, while automatic, cone-shaped sediment traps have been anchored in deep oceanic areas. Vertical fluxes toward 2300 m depth off Coquimbo were dominated by calcium carbonate (~70 mg m-2 d-1) instead of particulate organic carbon (POC ~7 mg m-2 d-1), where foraminifers (Neogloboquadrina pachyderma) and faecal pellets of Euphausia mucronata and Oikopleura spp, played important roles as vehicles for carbonate and carbon, respectively. In coastal upwelling systems, (i. e. Concepción), the dominant vertical flux was POC, mainly... |
| Tipo: Journal article |
Palavras-chave: Particulate organic matter; Fluxes; Oxygen minimum zone; Zooplankton functional groups; Sediment traps; Central Chile. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300007 |
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| Muresan Paslaru, Bogdan; Cossa, Daniel; Richard, S; Burban, B. |
| The distribution and speciation of mercury (Hg) in air, rain, and surface waters from the artificial tropical lake of Petit-Saut in French Guiana were investigated during the 2003/04 period. In the air, total gaseous mercury (TGM) at the dam station averaged 12 +/- 2 pmol m(-3) of which > 98% was gaseous elemental mercury (GEM). GEM distribution depicted a day-night cycling with high concentrations (up to 15 pmol m(-3)) at dawn and low concentrations (down to 5 pmol m(-3)) at nightfall. Reactive gaseous mercury (RGM) represented < 1% of the GEM with a mean concentration of 4 3 fmol m(-3). Diel RGM variations were negatively related to GEM. In the rain, the sum of all Hg species in the unfiltered (HgTUNF) averaged 16 +/- 112 pmol L-1. Temporal... |
| Tipo: Text |
Palavras-chave: Fluxes; Speciation; Mercury; Artificial reservoir; Atmosphere. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3329.pdf |
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| Vialard, Jerome; Foltz, G. R.; Mcphaden, M. J.; Duvel, J. P.; De Boyer Montegut, Clement. |
| A moored buoy was recently deployed at 8 degrees S, 67 degrees E in the shallow thermocline region of the Indian Ocean known as "Seychelles-Chagos Thermocline Ridge'' (SCTR), where the Madden Julian Oscillation (MJO) is associated with strong sea surface temperature (SST) variability. We use observations from this mooring to describe the oceanic signature of two MJOs between November 2007 and February 2008. The four-month average upper ocean heat balance was largely between heating by atmospheric forcing (2.0 +/- 0.3 degrees C/month) and a significant cooling by subsurface processes (-2.2 +/- 0.8 degrees C/month), consistent with climatological Ekman pumping in the region. The two MJO events resulted in strong intraseasonal SST variations (1.5 to 2 degrees... |
| Tipo: Text |
Palavras-chave: Layer heat balance; Paific; Perturbations; Prediction; Fluxes. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00185/29636/27988.pdf |
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| Muresan Paslaru, Bogdan; Cossa, Daniel; Jezequel, D; Prevot, F; Kerbellec, S. |
| Solid sediment, pore and epibenthic waters were collected from the Thau lagoon (France) in order to study the post depositional partition and mobility of mercury and monomethylmercury in an organic rich sediment. Total Hg (HgT) and monomethymercury (MMHg) profiles were produced in both dissolved and solid phases. The distribution of HgT in the solid appeared to be related to the historical changes in the Hg inputs into the lagoon. HgT was in equilibrium between solid and solution in the sulfidic part of the cores, with a mean log Kd of 4.9 +- 0.2. The solid appeared to be a source of HgT for pore water in the upper oxic to suboxic parts of the cores. The MMHg represented a small fraction of HgT: 3-15 % and 0.02-0.80 % in the dissolved and in the solid... |
| Tipo: Text |
Palavras-chave: Fluxes; Partition; Sediment; Lagoon; Methylmercury; Mercury. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2083.pdf |
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| Maurice, Laurence. |
| The main problem of the Girond estuary is a pollution by the cadmium. During this last ten years, the good quality of the water is proved by the analysis of the main physico - chemical and biochemical parameters and bacteria. But since 1989, straight to the Blayais power station, the BOD5 varied between 2 and 3,5 mg.l-1 and a diminution of the dissolved oxygen has been observed; it's probably caused by the accumulation of biodegradable organic matter in the maximum turbidity zone during years characterized by low river flows. For average river flow, urban discharges takes part for 20 % in total fluxes of BD05; in 1991, this part attempts 35 %. During the last 7 years, the pluriannual evolution of the nitrate concentrations measured in the Garonne river... |
| Tipo: Text |
Palavras-chave: Oxygène; Sels nutritifs; Matière organique; Bactéries; Apports; Estuaire Gironde; Oxygen; Nutrients; Organic matter; Bacteria; Fluxes; Gironde estuary. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00037/14855/12178.pdf |
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| Mazouni, Nabila; Gaertner, J; Deslous-paoli, Jean-marc. |
| This study was based on in situ experiments conducted in a shellfish lagoon (Thau, France) to determine the interactions between suspended oyster Crassostrea gigas Thunberg cultures and their environment at a seasonal scale. Three groups of descriptors were considered simultaneously during the course of the study: the taxonomic composition of an oyster culture unit (OCU), the nutrient and oxygen exchanges at the OCU-water interface (fluxes) and the water-column characteristics (water). We used a multiple factorial analysis (MFA) to assess in a single reference frame: (1) the seasonal organisation of the taxonomic groups which compose the OCU and (2) the interactions between this multispecific assemblage and the water column. We found strong seasonal... |
| Tipo: Text |
Palavras-chave: Ascidians; Fluxes; Multicompartment approach; Biofouling; Oyster culture. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/1996/publication-809.pdf |
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| Mazouni, Nabila; Deslous-paoli, Jean-marc; Landrein, Sonia. |
| The impact of suspended oyster culture (Crassostrea gigas, Thunberg) on oxygen and nutrient fluxes has been studied in situ, in a coastal lagoon (Thau, France), during a seasonal cycle. On the first plan of the multiple factorial correspondences analysis (MCA), seasons were well discriminated. The fluxes were maximum in summer and minimum in winter. However, this seasonal pattern was not only linked to the water temperature, as autumn and spring (similar temperatures of about 12 degrees C) were distinct in the second factorial plan (2.3). Oxygen uptake by the oyster cultures varied between 0 mu mol m(-2) h(-1) (January) and 11 823 +/- 377 mu mol m(-2) h(-1) (July). Ammonia and nitrate-nitrites were released into the water column respectively at a rate of... |
| Tipo: Text |
Palavras-chave: Oxygen; Nutrients; Fluxes; Oyster culture; Oxygène; Nutriments; Flux; Elevage ostréicole. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-840.pdf |
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| Moat, B. I.; Sinha, B.; Josey, S. A.; Robson, J.; Ortega, P.; Sévellec, Florian; Holliday, N. P.; Mccarthy, G. D.; New, A. L.; Hirschi, J. J.-m.. |
| An ocean mixed layer heat budget methodology is used to investigate the physical processes determining subpolar North Atlantic (SPNA) sea surface temperature (SST) and ocean heat content (OHC) variability on decadal-multidecadal timescales using the state-of-the-art climate model HadGEM3-GC2. New elements include development of an equation for evolution of anomalous SST for interannual and longer timescales in a form analogous to that for OHC, parameterization of the diffusive heat flux at the base of the mixed layer and analysis of a composite AMOC event. Contributions to OHC and SST variability from two sources are evaluated i) net ocean-atmosphere heat flux and ii) all other processes, including advection, diffusion and entrainment for SST. Anomalies in... |
| Tipo: Text |
Palavras-chave: Atmosphere-ocean interaction; Climate variability; Energy budget; Balance; Fluxes; Heat budgets; Fluxes; Surface temperature. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00502/61395/65060.pdf |
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| Cerovecki, Ivana; Talley, Lynne D.; Mazloff, Matthew R.; Maze, Guillaume. |
| Subantarctic Mode Water (SAMW) is examined using the data-assimilating, eddy-permitting Southern Ocean State Estimate, for 2005 and 2006. Surface formation due to air–sea buoyancy flux is estimated using Walin analysis, and diapycnal mixing is diagnosed as the difference between surface formation and transport across 30°S, accounting for volume change with time. Water in the density range 26.5 < σθ < 27.1 kg m−3 that includes SAMW is exported northward in all three ocean sectors, with a net transport of (18.2, 17.1) Sv (1 Sv ≡ 106 m3 s−1; for years 2005, 2006); air–sea buoyancy fluxes form (13.2, 6.8) Sv, diapycnal mixing removes (−14.5, −12.6) Sv, and there is a volume loss of (−19.3, −22.9) Sv mostly occurring in the strongest SAMW formation... |
| Tipo: Text |
Palavras-chave: Atmosphere-ocean interaction; Buoyancy; Fluxes; Ocean circulation. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00154/26487/24596.pdf |
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| Munaron, Dominique; Dubernet, Jf; Delmas, F; Stanisiere, Jean-yves; Scribe, P. |
| Our study aims at making progress the estimate of herbicide and nutrient inputs to the Marennes-Oleron bay which could influence summer oysters mortalities, and to bring, a better understanding of the impact on coastal ecosystems by modelling the dynamics of these compounds in the shellfish-farming area. The development of a strategy adapted to the river Charente and its estuary reveals that agricultural activity on the watershed area is omnipresent, as well on the level of the nitrogen as on the one of herbicides contributions. It is thus necessary to specify Charente fluxes, which is the main tributary of the Marennes-Oleron bay, in order to better characterize its impact on shell fish-farming activity. Hydrodynamic modelling will constitute an... |
| Tipo: Text |
Palavras-chave: Marennes Oleron bay; River Charente; Modelling; Fluxes; Nutrients; Herbicides. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3612.pdf |
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| Donis, Daphne; Holtappels, Moritz; Noss, Christian; Cathalot, Cecile; Hancke, Kasper; Polsenaere, Pierre; Wenzhoefer, Frank; Lorke, Andreas; Meysman, Filip J. R.; Glud, Ronnie N.; Mcginnis, Daniel F.. |
| The quantification of benthic fluxes with the aquatic eddy correlation (EC) technique is based on simultaneous measurement of the current velocity and a targeted bottom water parameter (e.g., O2, temperature). High-frequency measurements (64 Hz) are performed at a single point above the seafloor using an acoustic Doppler velocimeter (ADV) and a fast-responding sensor. The advantages of aquatic EC technique are that 1) it is noninvasive, 2) it integrates fluxes over a large area, and 3) it accounts for in situ hydrodynamics. The aquatic EC has gained acceptance as a powerful technique; however, an accurate assessment of the errors introduced by the spatial alignment of velocity and water constituent measurements and by their different response times is... |
| Tipo: Text |
Palavras-chave: Turbulence; Boundary layer; Fluxes; Instrumentation/sensors; Optimization; Experimental design. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00275/38577/37102.pdf |
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| Azandegbe, Afi; Poly, Franck; Andrieux, Francoise; Kerouel, Roger; Philippon, Xavier; Nicolas, Jean-louis. |
| Bacterial community structure and some biogeochemical parameters were studied in the sediment of two Pacific oyster farming sites, Aber Benoît (AB) and Rivière d'Auray (RA) in Brittany (France), to examine the ecological impact of oysters and to evaluate the emission of sulfide and ammonia from sediment. At AB, the organic matter accumulated in the sediment beneath the oyster tables was rapidly mineralized, with strong fluxes of ammonia and sulfide that reached 1014 μmol m−2 h−1 - and 215 μmol m−2 h−1, respectively, in June 2007. At RA, the fluxes were about half as strong on average and better distributed through the year. The ammonia and sulfide concentrations in the overlying water never reached levels that would be toxic to oysters in either site, nor... |
| Tipo: Text |
Palavras-chave: Sediment; Biogeochemical parameters; Fluxes; Bacterial structure; Crassostrea gigas. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19010/17083.pdf |
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| Wanninkhof, Rik; Pickers, Penelope A.; Omar, Abdirahman M.; Sutton, Adrienne; Murata, Akihiko; Olsen, Are; Stephens, Britton B.; Tilbrook, Bronte; Munro, David; Pierrot, Denis; Rehder, Gregor; Magdalena Santana-casiano, J.; Mueller, Jens D.; Trinanes, Joaquin; Tedesco, Kathy; O'Brien, Kevin; Currie, Kim; Barberols, Leticia; Telszewski, Maciej; Hoppema, Mario; Ishii, Masao; Gonzalez-davila, Melchor; Bates, Nicholas R.; Metzl, Nicolas; Suntharalingam, Parvadha; Feely, Richard A.; Nakaoka, Shin-ichiro; Lauvset, Siv K.; Takahashi, Taro; Steinhoff, Tobias; Schuster, Ute. |
| The Surface Ocean CO2 NETwork (SOCONET) and atmospheric Marine Boundary Layer (MBL) CO2 measurements from ships and buoys focus on the operational aspects of measurements of CO2 in both the ocean surface and atmospheric MBLs. The goal is to provide accurate pCO(2) data to within 2 micro atmosphere (mu atm) for surface ocean and 0.2 parts per million (ppm) for MBL measurements following rigorous best practices, calibration and intercomparison procedures. Platforms and data will be tracked in near real-time and final quality-controlled data will be provided to the community within a year. The network, involving partners worldwide, will aid in production of important products such as maps of monthly resolved surface ocean CO2 and air-sea CO2 flux... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Network; Oceanography; Fluxes; Best practices. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00675/78725/80992.pdf |
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| Registros recuperados: 21 | |
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