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| Registros recuperados: 31 | |
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| Gladyshev, S; Arhan, Michel; Sokov, A; Speich, Sabrina. |
| The properties and circulation of water masses leaving and entering the Atlantic Ocean south of Africa are examined using data from a hydrographic and Lowered acoustic Doppler current profiler section from South Africa to the southern limit of the Antarctic Circumpolar Current (ACC). At the upper levels, the ACC fronts are well determined using either classical water mass definitions or gradient-based criteria. While the locations of the Subantarctic Front (SAF), Polar Front (PF), and Southern ACC Front (SACCF) seem controlled by the neighbouring ridges, that of the Subtropical Front (STF) is much influenced in this region (similar to 10 degrees E) by northwestward propagating Agulhas rings. No large amount of Subantarctic Mode Water (SAMW) is observed,... |
| Tipo: Text |
Palavras-chave: Water masses; Fronts; Bottom circulation; Transport; Agulhas eddies; Antarctic Circumpolar Current. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6097.pdf |
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| Thomas, Leif N.; Shakespeare, Callum J.. |
| A simple analytical model is used to elucidate a potential mechanism for steady-state mode water formation at a thermohaline front that involves frontogenesis, submesoscale lateral mixing, and cabbeling. This mechanism is motivated in part by recent observations of an extremely sharp, density-compensated front at the North Wall of the Gulf Stream. Here, the intergyre, along-isopycnal, salinity-temperature difference is compressed into a span of a few kilometers, making the flow susceptible to cabbeling. The sharpness of the front is caused by frontogenetic strain, which is presumably balanced by submesoscale lateral mixing processes. The balance is studied with the simple model, and a scaling is derived for the amount of water mass transformation resulting... |
| Tipo: Text |
Palavras-chave: Circulation/ Dynamics; Frontogenesis/frontolysis; Fronts; Ocean dynamics; Atm/Ocean Structure/ Phenomena; Water masses. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00351/46243/46107.pdf |
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| Swart, Sebastiaan; Speich, Sabrina. |
| Swart et al. (2010) applied altimetry data to the gravest empirical mode south of Africa to yield a 16 year time series of temperature and salinity sections. In this study we use these thermohaline sections to derive weekly estimates of heat content (HC) and salt content (SC) at the GoodHope meridional transect of the Antarctic Circumpolar Current (ACC). These estimates compare favorably to observed data. The resulting 16 year time series of HC and SC estimates are used to explain the subsurface thermohaline variability at each ACC front and frontal zone. The variability at the Subantarctic Zone (SAZ) is principally driven by the presence of Agulhas Rings, which occur in this region approximately 2.7 times per annum and are responsible for the longest and... |
| Tipo: Text |
Palavras-chave: Altimetry; ACC; Fronts. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11307/7892.pdf |
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| Bianucci, L.. |
| En este trabajo se caracterizaron los frentes de marea en la Plataforma Continental Argentina al sur de 40°S y los flujos de CO2 entre el mar y la atmósfera en la región, analizándose su relación con dichos frentes. Los frentes de marea separan aguas costeras cuasi-homogéneas de aguas estratificadas de la plataforma media. La zona costera se homogeneiza por la mezcla vertical producida por fricción de las energéticas corrientes de marea que se dan en la región. La plataforma media se encuentra estratificada en verano debido al calentamiento superficial del mar, presentando una termoclina estacional bien desarrollada. La mezcla vertical a cada lado de los frentes y los movimientos verticales en la zona frontal afectan a la producción primaria y a los flujos... |
| Tipo: Theses and Dissertations |
Palavras-chave: Fronts; Atmospheric fronts; Continental shelves; Air-sea interaction; Climatology; Tidal flow; Seasonal distribution; Climatology; Continental shelves. |
| Ano: 2004 |
URL: http://hdl.handle.net/1834/3856 |
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| Wenegrat, Jacob O.; Thomas, Leif N.; Gula, Jonathan; Mcwilliams, James C.. |
| Non-conservative processes change the potential vorticity (PV) of the upper ocean, and later, through the subduction of surface waters into the interior, affect the general ocean circulation. Here we focus on how boundary layer turbulence, in the presence of submesoscale horizontal buoyancy gradients, generates a source of potential vorticity at the ocean surface through a balance known as the Turbulent ThermalWind. This source of PV injection at the submesoscale can be of similar magnitude to PV fluxes from the wind and surface buoyancy fluxes, and hence can lead to a net injection of PV onto outcropped isopycnals even during periods of surface buoyancy loss. The significance of these dynamics is illustrated using a high-resolution realistic model of the... |
| Tipo: Text |
Palavras-chave: Ageostrophic circulations; Atmosphere-ocean interaction; Fronts; Ocean dynamics; Potential vorticity; Boundary layer. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00452/56347/57937.pdf |
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| Viñas, M.D.; Marrari, M.; Di Mauro, R.; Cepeda, G.D.; Padovani, L.N.. |
| The information gathered in Argentine anchovy (Engraulis anchoita) Northern population assessment cruises allowed to perform studies on the zooplankton community of the Buenos Aires shelf since 1995. In this work the most relevant results as regards the taxonomy and size structure of the community, faunistic areas, and 'key' species in relation to the hydrographic conditions and frontal systems of the region are presented. Besides, the consequences those results might have on Argentine anchovy trophic ecology are analyzed. The taxonomic groups studied included copepods, cladocerans, appendicularians, chaetognaths, amphipods, and euphausiids. The multivariate analysis applied to quantitative data allowed to clearly distinguish three faunistic areas with... |
| Tipo: Journal Contribution |
Palavras-chave: Zooplankton; Biogeography; Fauna; Fronts; Trophic relationships; Abundance; Pelagic fisheries. |
| Ano: 2013 |
URL: http://hdl.handle.net/1834/5497 |
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| Drushka, Kyla; Asher, William E.; Sprintall, Janet; Gille, Sarah T.; Hoang, Clifford. |
| Surface salinity variability on O(1-10) km lateral scales (the submesoscale) generates density variability and thus has implications for submesoscale dynamics. Satellite salinity measurements represent a spatial average over horizontal scales of approximately 40-100 km but are compared to point measurements for validation, so submesoscale salinity variability also complicates validation of satellite salinities. Here, we combine several databases of historical thermosalinograph (TSG) measurements made from ships to globally characterize surface submesoscale salinity, temperature, and density variability. In river plumes; regions affected by ice melt or upwelling; and the Gulf Stream, South Atlantic, and Agulhas Currents, submesoscale surface salinity... |
| Tipo: Text |
Palavras-chave: Small scale processes; Freshwater; Fronts; Sea surface temperature; Oceanic variability. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00676/78805/81042.pdf |
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| Bauer, Robert Klaus; Fromentin, Jean-marc; Demarcq, Herve; Bonhommeau, Sylvain. |
| We investigated the habitat utilization, vertical and horizontal behaviour of Atlantic bluefin tuna Thunnus thynnus (ABFT) in relation to oceanographic conditions in the northwestern Mediterranean Sea, based on 36 pop-up archival tags and different environmental data sets. Tags were deployed on early mature ABFT (127–255 cm) between July and November in 2007-2014, on the shelf area off Marseille, France. The data obtained from these tags provided 1643 daily summaries of ABFT vertical behaviour over 8 years of tag deployment. Based on a hierarchical clustering of this data, we could identify four principle daily vertical behaviour types, representing surface (≦10m) and subsurface (10–100 m) orientation, moderate (50–200 m) and deep (≧200m) diving behaviour.... |
| Tipo: Text |
Palavras-chave: Thunnus thynnus; Habitat use; Spike dives; Fronts; Thermal stratification; Archival tags. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00382/49329/49709.pdf |
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| Romero, O. E.; Kim, J. -h.; Barcena, M. A.; Hall, I. R.; Zahn, R.; Schneider, R.. |
| The hydrography of the Indian-Atlantic Ocean gateway has been connected to high-latitude climate dynamics by oceanic and atmospheric teleconnections on orbital and suborbital timescales. A wealth of sedimentary records aiming at reconstructing the late Pleistocene paleoceanography around the southern African continent has been devoted to understanding these linkages. Most of the records are, however, clustered close to the southern South African tip, with comparatively less attention devoted to areas under the direct influence of frontal zones of the Southern Ocean/South Atlantic. Here we present data of the composition and concentration of the diatom assemblage together with bulk biogenic content and the alkenone-based sea surface temperature (SST)... |
| Tipo: Text |
Palavras-chave: Agulhas; SST; Diatoms; Fronts; Silica; Southern Ocean. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00294/40555/39440.pdf |
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| Ayata, Sakina-dorothee; Stolba, Robin; Comtet, Thierry; Thiebaut, Eric. |
| The relationship between meroplankton distribution and spatio-temporal variability of coastal mesoscale hydrological structure was investigated in the northern Bay of Biscay, North-East Atlantic. For the three coastal polychaetes studied, i.e. Pectinaria koreni, Owenia fusiformis and Sabellaria alveolata, the highest larval abundances were sampled in low-salinity, low-density and high-temperature river plume waters. For two species (P. koreni and O. fusiformis), maximal abundances were observed in the surface and thermocline layers due to ontogenic migrations. Variance partitioning based on multiple regression and redundancy analyses was used to assess the relative roles played by the hydrological environment alone, the geographical space alone and their... |
| Tipo: Text |
Palavras-chave: Meroplankton; Larval transport; Mesoscale structures; River plume; Fronts; Owenia fusiformis; Pectinaria koreni; Sabellaria alveolata; Bay of Biscay. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00240/35131/33632.pdf |
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| Garreau, Pierre; Dumas, Franck; Louazel, Stephanie; Correard, Stephanie. |
| The Mediterranean Sea is often referred as a “pocket ocean” exhibiting many processes that are primary interest the global ocean circulation given the opportunity to investigate a large panel of oceanic features in a relatively restrained area. Recent field experiments based on the multi-plateform integrated monitoring MOOSE or on intensive targeted experiment HYMEX revisited the hydrology and the dynamics of the Western Basin. Such approaches emphasized the ubiquity of the fine scale dynamics in the Mediterranean dynamics. An overview of the observed processes during 5 recent fields experiments are presented and discussed regarding meso- and submeso-scale processes. |
| Tipo: Text |
Palavras-chave: Mesoscale phenomena; Western Mediterranean; Fronts. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00582/69398/67247.pdf |
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| Floodgate, G.d.; Lochte, K.; Egan, B.. |
| The data obtained in surveys to investigate the bacteriological aspects of the biology of two contrasting frontal systems has shown that the Inherent homeostasis and the complexity of the environment, together with the Imprecision of the data, lead to biomass values that are difficult to interpret in terms of the physical factors governing the formation of fronts. Although biochemical measurements offer some promise of providing more reliable and less confusing information, the oeed to develop high precision methods that can be made very frequently is emphasised. |
| Tipo: Text |
Palavras-chave: Bacteria; Discontinuities; Fronts; Methodology. |
| Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/00306/41742/40953.pdf |
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| Registros recuperados: 31 | |
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