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| Registros recuperados: 44 | |
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| Sokolov, Serguei; Rintoul, Stephen R.. |
| Maps of the gradient of sea surface height (SSH) and sea surface temperature (SST) reveal that the Antarctic Circumpolar Current (ACC) consists of multiple jets or frontal filaments. The braided and patchy nature of the gradient fields seems at odds with the traditional view, derived from hydrographic sections, that the ACC is made up of three continuous circumpolar fronts. By applying a nonlinear fitting procedure to 638 weekly maps of SSH gradient (del SSH), it is shown that the distribution of maxima in del SSH (i.e., fronts) is strongly peaked at particular values of absolute SSH (i.e., streamlines). The association between the jets and particular streamlines persists despite strong topographic and eddy - mean flow interactions, which cause the jets to... |
| Tipo: Text |
Palavras-chave: Jets; Currents; Sea surface temperature; Ocean circulation. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34616/32952.pdf |
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| Arzel, Olivier; Huck, Thierry. |
| A simplified coupled ocean-atmosphere model, consisting of a one-layer bidimensional ocean model and a one-layer unidimensional energy balance atmospheric model [J. Clim. 13 (2000) 232] is used to study the unstable interactions between zonal winds and ocean gyres. In a specific range of parameters, decadal variability is found. Anomalies, quite homogeneous zonally, show small-scale wavelength in latitude: perturbations emerge and grow at the southern limb of the intergyre boundary and propagate southward before decaying. The wind stress anomalies are proportional to the meridional gradient of the atmospheric temperature anomalies: this ratio acts as a positive amplification factor, as confirmed by a parameter sensitivity analysis. Assuming... |
| Tipo: Text |
Palavras-chave: Ocean atmosphere system; Air sea interaction; Air sea coupling; Ocean circulation. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-647.pdf |
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| Broecker, Wallace; Clark, Elizabeth; Barker, Stephen; Hajdas, Irena; Bonani, Georges; Moreno, Eva. |
| Radiocarbon age differences for pairs of coexisting late glacial age benthic and planktic foraminifera shells handpicked from 10 sediment samples from a core from a depth of 2.8 km in the western equatorial Pacific are not significantly different from that of 1600 years calculated from measurements on prenuclear seawater. This places a lower limit on the depth of the interface for the hypothetical radiocarbon-depleted glacial age seawater reservoir required to explain the 190% drop in the (14)C/C for atmospheric CO(2), which occurred during the mystery interval (17.5 to 14.5 calendar years ago). These measurements restrict the volume of this reservoir to be no more than 35% that of the ocean. Further, (14)C measurements on a single Last Glacial Maximum age... |
| Tipo: Text |
Palavras-chave: Ocean circulation; Mystery interval; Radiocarbon dating. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00233/34449/32884.pdf |
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| Ollitrault, Michel; Rannou, Jean Philippe. |
| During the first decade of the twenty-first century, more than 6000 Argo floats have been launched over the World Ocean, gathering temperature and salinity data from the upper 2000 m, at a 10-day or so sampling period. Meanwhile their deep displacements can be used to map the ocean circulation at their drifting depth (mostly around 1000 m). A comprehensive processing of the whole Argo dataset collected prior to 1 January 2010 has been performed to produce a world-wide dataset of deep displacements. This numerical atlas, named ANDRO, after a traditional dance of Brittany meaning a swirl, comprises some 600 000 deep displacements. These displacements, based on Argo or GPS surface locations only, have been fully checked and corrected for possible errors found... |
| Tipo: Text |
Palavras-chave: Lagrangian circulation/transport; Large-scale motions; Ocean circulation. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00138/24901/22994.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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| Ollitrault, Michel; Colin De Verdiere, Alain. |
| The mean ocean circulation near 1000-m depth is estimated with 100-km resolution from the Argo float displacements collected before 1 January 2010. After a thorough validation, the 400 000 or so displacements found in the 950–1150 dbar layer and with parking times between 4 and 17 days allow the currents to be mapped at intermediate depths with unprecedented details. The Antarctic Circumpolar Current (ACC) is the most prominent feature, but western boundary currents (and their recirculations) and alternating zonal jets in the tropical Atlantic and Pacific are also well defined. Eddy kinetic energy (EKE) gives the mesoscale variability (on the order of 10 cm2 s−2 in the interior), which is compared to the surface geostrophic altimetric EKE showing e-folding... |
| Tipo: Text |
Palavras-chave: Circulation; Dynamics; Currents; Dynamics; Large-scale motions; Ocean circulation. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00174/28512/26877.pdf |
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| Skinner, Luke C.; Waelbroeck, Claire; Scrivner, Adam E.; Fallon, Stewart J.. |
| Recent theories for glacial-interglacial climate transitions call on millennial climate perturbations that purged the deep sea of sequestered carbon dioxide via a "bipolar ventilation seesaw." However, the viability of this hypothesis has been contested, and robust evidence in its support is lacking. Here we present a record of North Atlantic deep-water radiocarbon ventilation, which we compare with similar data from the Southern Ocean. A striking coherence in ventilation changes is found, with extremely high ventilation ages prevailing across the deep Atlantic during the last glacial period. The data also reveal two reversals in the ventilation gradient between the deep North Atlantic and Southern Ocean during Heinrich Stadial 1 and the Younger Dryas.... |
| Tipo: Text |
Palavras-chave: Ocean circulation; Carbon cycle; Abrupt change. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40153/39327.pdf |
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| Hufnagl, Marc; Payne, Mark; Lacroix, Genevieve; Bolle, Loes J.; Daewele, Ute; Dickey-collas, Mark; Gerkema, Theo; Huret, Martin; Janssen, Frank; Kreus, Markus; Paetsch, Johannes; Pohlmann, Thomas; Ruardij, Piet; Schrum, Corinna; Skogen, Morten D.; Tiessen, Meinard C. H.; Petitgas, Pierre; Van Beek, Jan K. L.; Van Der Veer, Henk W.; Callies, Ulrich. |
| Hydrodynamic Ocean Circulation Models and Lagrangian particle tracking models are valuable tools e.g. in coastal ecology to identify the connectivity between offshore spawning and coastal nursery areas of commercially important fish, for risk assessment and more for defining or evaluating marine protected areas. Most studies are based on only one model and do not provide levels of uncertainty. Here this uncertainty was addressed by applying a suite of 11 North Sea models to test what variability can be expected concerning connectivity. Different notional test cases were calculated related to three important and well-studied North Sea fish species: herring (Clupea harengus), and the flatfishes sole (Solea solea) and plaice (Pleuronectes platessa). For sole... |
| Tipo: Text |
Palavras-chave: Ocean circulation; Lagrangian approach; Variability; Marine protected areas; Renewable energy; Wind park; Model intercomparison; Ensemble. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00385/49660/50198.pdf |
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| Simanca, J.; Fernández, L.; Viamontes, J.; Ramírez, O.; Arriaza, L.; Ochoa, J.L.. |
| Se modificó el patrón de circulación en la periferia acuática del Golfo de Batabanó a partir de la caracterización estadística de la corriente residual filtrada de series temporales provenientes de 12 estaciones correntométricas obtenidas de julio de 1988 a agosto de 1989. Para el filtraje de la componente no periódica se utilizó el filtro Doodson. Los resultados muestran que las corrientes residuales son débiles, con intensidades que variaron entre 1.2 - 5.5 cm/s como promedio por estaciones, además, las velocidades resultaron ser más estables en dirección que en intensidad. Se observó salida de agua por el extremo SE del golfo y por algunos canales al E de la Isla de la Juventud, y entrada de agua por el E del golfo en su límite con el Golfo de Cazones y... |
| Tipo: Conference Material |
Palavras-chave: Time series; Current measurement; Coastal currents; Ocean circulation. |
| Ano: 2006 |
URL: http://hdl.handle.net/1834/2230 |
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| Registros recuperados: 44 | |
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