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| Registros recuperados: 82 | |
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| Abrantes, F; Moita, Mt. |
| Diatom and coccolithophorid abundance and diatom assemblage composition found in the water column along the Portuguese margin, during upwelling and non-upwelling conditions, are compared to the distribution patterns observed in the recent sediments from the same area. The water column results indicate a one order of magnitude increase in phytoplankton biomass during upwelling conditions (summer). with diatoms being the most important contributors. Coccolithophorids, on the contrary, dominate the phytoplankton in winter (non-upwelling). The comparison of the upwelling and non-upwelling spatial distribution of these phytoplankton groups to their sedimentary record reveals the sediment record as a reflection of the upwelling situation, preserving most of its... |
| Tipo: Text |
Palavras-chave: Upwelling; Portugal; Diatomée; Colonne d’eau; Sédiment; Upwelling; Portugal; Diatom; Water column; Sediment. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43613/43915.pdf |
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| Carlier, Antoine; Chauvaud, Laurent; Van Der Geest, Matthijs; Le Loc'H, Francois; Le Duff, Michel; Vernet, Marc; Raffray, Jean; Diakhate, Djibril; Labrosse, Pierre; Wague, Abdoulaye; Le Goff, Clement; Gohin, Francis; Chapron, Bertrand; Clavier, Jacques. |
| Banc d’Arguin (BA), Mauritania, is a nationally protected shallow gulf > 10,000 km2 between the Sahara desert and the upwelling system off the Mauritanian coast. In the southeast, BA consists of a 500 km2 tidal flat, the most important wintering site for shorebirds using the East Atlantic Flyway. The Mauritanian upwelling-driven phytoplankton production supports the most productive fisheries worldwide, but little is known about its trophic role in the functioning of the inshore BA food web. Using stable isotopes as trophic tracers to distinguish between upwelling-driven phytoplankton, open ocean phytoplankton, and benthic primary producers, we assessed the spatial extent to which the inshore BA food web is fuelled by upwelling-driven phytoplankton... |
| Tipo: Text |
Palavras-chave: Banc d'Arguin; West Africa; Food web structure; Remote sensing; Stable isotope; Upwelling. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00269/37999/36078.pdf |
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| Malaize, B.; Joly, C.; Venec-peyre, M. -t.; Bassinot, F.; Caillon, N.; Charlier, K.. |
| High-resolution faunal and isotopic analyses of foraminifera were performed on core MD96-2073 (10 degrees 94'N, 52 degrees 62'E, 3142 m depth), located close to Socotra Island in the upwelling area of the Somali Basin ( NW Indian Ocean). This work focuses on Marine Isotopic Stage 6.5 in order to reconstruct paleo-upwelling changes and their links with the Arabian Sea summer monsoon and the migration of the Intertropical Convergence Zone (ITCZ). Correspondence and cluster analyses of planktonic foraminiferal abundances, partly controlled by temperature and water mass productivity, together with an upwelling intensification index, show the occurrence of a strong upwelling between 176 and 165 ka. This upwelling intensification responds to a northward... |
| Tipo: Text |
Palavras-chave: Paleoclimatology; Foraminifera; Isotopes; Indian monsoon; ITCZ; Sapropels; Upwelling. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34487/33433.pdf |
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| Ndoye, S; Capet, Xavier; Estrade, Philippe; Machu, Eric; Kounta, L; Sow, B; Diakhate, M; Gayet, At. |
| The regional ocean circulation along the Southern Senegal shelf is studied using a numerical model for varying forcing fields during the upwelling season (November-May). The main objective is to study the shelf circulation of the marine environment in the Southern Senegal Upwelling Shelf (SSUS), the Lagrangian pathways by which waters are transported to the surface in the upwelling tongue and the fate of these waters. Model results are compared with hydrographic measurements during UPSEN2-ECOAO survey and satellite images datasets. The upwelling source waters and also the warm nearshore waters are analyzed, from a Lagrangian point of view, by computing the paths of particles that are passively advected by the regional ocean model velocity field (ROMS). It... |
| Tipo: Text |
Palavras-chave: Upwelling; Ocean circulation; Modeling; Coastal dynamics; Shelf; ROMS.. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00472/58346/60900.pdf |
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| Xue, Liang; Gao, Libao; Cai, Wei-jun; Yu, Weidong; Wei, Meng. |
| Using observational data collected south of Tasmania during 14 austral summer cruises during 1993-2011, we examined the response of sea surface fugacity of carbon dioxide (fCO(2)) to the Southern Annular Mode (SAM) shift, which occurred around 2000. In the southern part of the Southern Ocean (SO) or the Polar Zone (PZ) and the Polar Frontal Zone (PFZ), fCO(2) increased faster at the sea surface than in the atmosphere before the SAM shift, but not after the shift. In the northern part of the SO or the Subantarctic Zone (SAZ), however, surface fCO(2) increased faster than atmospheric fCO(2) both before and after the shift. The SAM shift had an important influence on the surface fCO(2) trend in the PZ and PFZ but not in the SAZ, which we attribute to... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Southern Annular Mode shift; Carbon cycling; Upwelling; South of Tasmania. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00292/40369/38947.pdf |
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| Vic, Clement; Capet, Xavier; Roullet, Guillaume; Carton, Xavier; ,. |
| Despite its climatic and ecosystemic significance, the coastal upwelling that takes place off Oman is not well understood. A primitive-equation, regional model forced by climatological wind stress is used to investigate its dynamics and to compare it with the better-known Eastern Boundary Upwellings (EBUs). The solution compares favorably with existing observations, simulating well the seasonal cycles of thermal structure, surface circulation (mean and turbulent), and sea-surface temperature (SST). There is a 1.5-month lag between the maximum of the upwelling-favorable wind-stress-curl forcing and the oceanic response (minima in sea-surface height and SST), which we attribute to onshore-propagating Rossby waves. A southwestward-flowing undercurrent... |
| Tipo: Text |
Palavras-chave: Oman; Upwelling; Arabian sea; ROMS; Rossby waves; Eddy kinetic energy. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00382/49350/49752.pdf |
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| Puillat, Ingrid; Lazure, Pascal; Jegou, Anne-marie; Lampert, Luis; Miller, P. |
| A synthesis of 9 years of hydrographic measurements, acquired during approximately 25 cruises (1992-2000) on the French continental shelf of the Bay of Biscay, is presented. The main focus is upon salinity distribution, as it is little known in this area. The whole of the data set covers I I months of the year, with some sampling fields repeated several times a year, for multiple years. This time-series allows temperature and salinity distributions to be studied together with their seasonal, inter-annual and mesoscale variability. The seasonal trend in temperature can be described in three stages, which are in agreement with past studies. Thermal stratification occurs between May and mid-September in a layer similar to 50 m in thickness, whereas the... |
| Tipo: Text |
Palavras-chave: Upwelling; Cold pool; River plumes; Seasonal variability; Salinity; Hydrography. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-779.pdf |
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| Turner, S.; Cadée, G.C.. |
| Dr Margaretha Brongersma-Sanders, palaeontologist, pioneer geochemist, geobiologist and oceanographer, Officer of the Order of Oranje Nassau was born 100 years ago (February 20th, 1905) in Kampen in The Netherlands. The fields of research that she covered during her lifetime include taxonomy of recent and fossil, principally freshwater fish; “fish kills” and mass mortality in the sea (especially of fish); taphonomy and preservation of fish; upwelling; anoxic conditions, linked to fish mortality and the origin of bituminous black shales and oil; red tides and harmful algal blooms; trace metal enrichment in recent and fossil sediments, especially the Kupferschiefer; the origin of evaporites; algal mats and stromatolites. She was the first to categorise fish... |
| Tipo: Article / Letter to the editor |
Palavras-chave: History; Biography; Bibliography; M. Brongersma-Sanders; Mass mortality research; Upwelling; Shell; 01.30; 42.81. |
| Ano: 2006 |
URL: http://www.repository.naturalis.nl/record/209643 |
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| Koné, Vamara; Koné, Yéfanlan José-Mathieu. |
| Les écosystèmes planctoniques marins sont soumis à des contraintes internes et externes qui influent sur leur dynamique. Celles-ci vont agir au niveau des processus éco physiologiques, biogéochimiques et comportementaux des organismes en présence. L'intégration de ces processus sous forme de système d'équations différentielles aboutit à des modèles permettant la stimulation de la dynamique et du comportement global de l'écosystème considéré. Les écosystèmes sont également contrôlés par les contraintes hydrodynamiques.Leur approche se fera grâce à des modèles couplés physique/biogéochimique. L'utilisation d'un modèle couplé qui prend en compte à la fois les processus dynamiques de la circulation océanique et les bases de l'activité biologique, permet une... |
| Tipo: Journal Contribution |
Palavras-chave: Seasonal variations; Upwelling. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/5772 |
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| Registros recuperados: 82 | |
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