Consulta: subjectFacets:"Eddies"
Registros recuperados: 24
Data/hora: 11/06/2024 09:07:49

Submesoscale streamers exchange water on the north wall of the Gulf Stream
Provedor de dados: 5
Autores: Klymak, Jody M.; Shearman, R. Kipp; Gula, Jonathan; Lee, Craig M.; D'Asaro, Eric A.; Thomas, Leif N.; Harcourt, Ramsey R.; Shcherbina, Andrey Y.; Sundermeyer, Miles A.; Molemaker, Jeroen; Mcwilliams, James C.
The Gulf Stream is a major conduit of warm surface water from the tropics to the subpolar North Atlantic. Here we observe and simulate a submesoscale (&lt;20km) mechanism by which the Gulf Stream exchanges water with subpolar water to the north. Along isopycnals, the front has a sharp compensated temperature-salinity contrast, with distinct mixed water between the two water masses 2 and 4km wide. This mixed water does not increase downstream despite substantial energy available for mixing. A series of streamers detrain this water at the crest of meanders. Subpolar water replaces the mixed water and resharpens the front. The water mass exchange accounts for a northward flux of salt of 0.5-2.5 psum(2)s(-1), (large-scale diffusivity O (100m(2)s(-1))). This is...
Tipo: Text
Palavras-chave: Ocean mixing; Gulf Stream; Submesoscale mixing; Eddies.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00600/71201/69570.pdf

Response of Total and Eddy Kinetic Energy to the recent spin up of the Beaufort Gyre
Provedor de dados: 5
Autores: Regan, Heather; Lique, Camille; Talandier, Claude; Meneghello, Gianluca.
The Beaufort Gyre in the Arctic Ocean has spun up over the past two decades in response to changes of the wind forcing and sea ice conditions, accumulating a significant amount of freshwater. Here a simulation performed with a high-resolution, eddy resolving model is analyzed in order to provide a detailed description of the total and eddy kinetic energy, and their response to this spin up of the gyre. On average, and in contrast to the typical open ocean conditions, the levels of mean and eddy kinetic energy are of the same order of magnitude, and the eddy kinetic energy is only intensified along the boundary and in the subsurface. In response to the strong anomalous atmospheric conditions in 2007, the gyre spins up and the mean kinetic energy almost...
Tipo: Text
Palavras-chave: Ocean; Arctic; Eddies; Ocean dynamics; Ocean models.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00598/71015/69288.pdf

Seasonal Mesoscale and Submesoscale Eddy Variability along the North Pacific Subtropical Countercurrent
Provedor de dados: 5
Autores: Qiu, Bo; Chen, Shuiming; Klein, Patrice; Sasaki, Hideharu; Sasai, Yoshikazu.
Located at the center of the western North Pacific Subtropical Gyre, the Subtropical Countercurrent (STCC) is not only abundant in mesoscale eddies, but also exhibits prominent submesoscale eddy features. Output from a 1/30 degrees high-resolution OGCM simulation and a gridded satellite altimetry product are analyzed to contrast the seasonal STCC variability in the mesoscale versus submesoscale ranges. Resolving the eddy scales of &gt;150 km, the altimetry product reveals that the STCC eddy kinetic energy and rms vorticity have a seasonal maximum in May and April, respectively, a weak positive vorticity skewness without seasonal dependence, and an inverse (forward) kinetic energy cascade for wavelengths larger (shorter) than 250 km. In contrast, the...
Tipo: Text
Palavras-chave: Circulation/ Dynamics; Eddies; Instability; Mesoscale processes; Observational techniques and algorithms; Altimetry; Models and modeling; Ocean models; Variability; Seasonal variability.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00245/35588/34142.pdf

Impact of eddies on surface chlorophyll in the South Indian Ocean
Provedor de dados: 5
Autores: Dufois, Francois; Hardman-mountford, Nick J.; Greenwood, Jim; Richardson, Anthony J.; Feng, Ming; Herbette, Steven; Matear, Richard.
A unique feature of the subtropical South Indian Ocean is the existence of anticyclonic eddies that have higher chlorophyll concentrations than cyclonic eddies. Off Western Australia, this anomalous behavior is related to the seeding of anticyclonic eddies with shelf water enriched in phytoplankton biomass and nutrients. Further off-shore, two mechanisms have been suggested to explain the eddy/chlorophyll relationship: (i) eddies originating from the Australian coast maintain their chlorophyll anomaly while propagating westward; and (ii) eddy-induced Ekman upwelling (downwelling) enhances (dampens) nutrient supply in anticyclonic (cyclonic) eddies. Here we describe the relationship between eddies and surface chlorophyll within the South Indian Ocean, and...
Tipo: Text
Palavras-chave: Eddies; Chlorophyll; Self-organizing map; Convective mixing; Eddy-induced Ekman pumping.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00233/34464/32862.pdf

South-Eastern Bay of Biscay eddy-induced anomalies and their effect on chlorophyll distribution
Provedor de dados: 5
Autores: Caballero, Ainhoa; Rubio, Anna; Ruiz, Simon; Le Cann, Bernard; Testor, Pierre; Mader, Julien; Hernandez, Carlos.
The analysis of deep-water glider hydrographic and fluorescence data, together with satellite measurements provides a new insight into eddy-induced anomalies within the South-Eastern Bay of Biscay, during summer. Two cyclonic eddies and a SWODDY have been observed in different glider transects and by means of different sources of satellite data. Vertical profiles reveal complex structures (characteristic of the second baroclinic mode): upward/downward displacement of the seasonal/permanent thermocline in the case of X13 and the opposite thermocline displacements in the case of the cyclones. This is a typical behaviour of mode-water and “cyclonic thinny” eddies. A qualitative analysis of the vertical velocities in the anticyclone indicates that though...
Tipo: Text
Palavras-chave: Eddies; Bay of Biscay; Glider; Hydrography; Mesoscale; Eddy-wind.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00326/43725/43176.pdf

Vortex erosion in a shallow-water model
Provedor de dados: 5
Autores: Louazel, Stephanie; Hua, Bach-lien.
The purpose of this paper is to study the erosion of eddies by filamentation in a shallow-water model where both fast and slow components of the dynamics coexist. In presence of inertia-gravity waves this filamentation process is indeed found to be altered. However, the information required to analyze the filamentation process is shown to be entirely captured by the slow component of the flow and regions of filament ejection can be identified from a diagnostic criterion based on instantaneous slow quantities. This is illustrated numerically in a reduced gravity model for an initial elliptic vortex of distributed potential vorticity in presence of Poincare waves. (C) 2004 American Institute of Physics.
Tipo: Text
Palavras-chave: Numerical model; Filamentation; Vorticity; Eddies.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-711.pdf

The Role of Curvature in Modifying Frontal Instabilities. Part II: Application of the Criterion to Curved Density Fronts at Low Richardson Numbers
Provedor de dados: 5
Autores: Buckingham, Christian; Gula, Jonathan; Carton, Xavier.
We continue our study of the role of curvature in modifying frontal stability. In Part I, we obtained an instability criterion valid for curved fronts and vortices in gradient wind balance (GWB): Φ′ = L′q′ &lt; 0, where L′ and q′ are the nondimensional absolute angular momentum and Ertel potential vorticity (PV), respectively. In Part II, we investigate this criterion in a parameter space representative of low-Richardson-number fronts and vortices in GWB. An interesting outcome is that, for Richardson numbers near 1, anticyclonic flows increase in q′, while cyclonic flows decrease in q′, tending to stabilize anticyclonic and destabilize cyclonic flow. Although stability is marginal or weak for anticyclonic flow (owing to multiplication by L′), the...
Tipo: Text
Palavras-chave: Eddies; Fronts; Instability; Ocean circulation; Potential vorticity; Frontogenesis/frontolysis; Vortices; Angular momentum.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00677/78919/81286.pdf

Observations of Layering under a Warm-Core Ring in the Gulf of Mexico
Provedor de dados: 5
Autores: Meunier, Thomas; Pallas Sanz, Enric; Tenreiro, Miguel; Ochoa, Jose; Angulo, Angel Ruiz; Buckingham, Christian.
Two glider transects in the Gulf of Mexico reveal fine-vertical-scale thermohaline structures within a Loop Current eddy (LCE). Partially compensating temperature and salinity anomalies are shown to organize as thin layers below the eddy and near its edges. The anomalies have vertical scales ranging from 2 to 60 m and extend laterally over distances up to 120 km. These structures are evident in synthetic acoustic reflectivity derived from the glider data and are reminiscent of the intense layering observed in seismic imagery around meddies, Agulhas rings, and warm-core Kuroshio rings. The observed layers are aligned with the geostrophic streamfunction rather than isopycnals and develop preferentially in zones of intense vertical shear. These observations...
Tipo: Text
Palavras-chave: Eddies; Mesoscale processes; Small scale processes; In situ oceanic observations; Quasigeostrophic models; Tracers.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00600/71242/69612.pdf

Evidence of abyssal eddies in the Brazil Basin - art. no. 3027
Provedor de dados: 5
Autores: Weatherly, G; Arhan, Michel; Mercier, Herle; Smethie, W.
[1] We report evidence of two deep cyclonic and two deep anticyclonic submesoscale eddies from World Oceanographic Circulation Experiment hydrographic casts made in the Brazil Basin. We infer that three of these were likely formed in or near the Deep Western Boundary Current (DWBC) of North Atlantic Deep Water (NADW), and thus had traveled eastward after formation. These eddies appear to be a new way for transporting NADW away from the DWBC to the ocean interior. One of the apparent cyclonic eddies appeared to be laterally in contact with one of the anticyclonic eddies. About 10 days later an attempt was made to resample the apparent eddies that had been in contact. These observations, although limited, are interpreted to indicate that they survived the...
Tipo: Text
Palavras-chave: Eddies; Deep Western Boundary Current; Eddy merging.
Ano: 2002
URL: https://archimer.ifremer.fr/doc/00000/10051/7796.pdf

Dynamic Interpolation of Sea Surface Height and Potential Applications for Future High-Resolution Altimetry Mapping
Provedor de dados: 5
Autores: Ubelmann, Clement; Klein, Patrice; Fu, Lee-lueng.
Many issues may challenge standard interpolation techniques to produce high-resolution gridded maps of sea surface height in the context of future missions like Surface Water and Ocean Topography (SWOT). The present study proposes a new method to address these challenges. Based on the conservation of potential vorticity, the method provides a simple dynamic approach to interpolation through temporal gaps between high spatial resolution observations. For gaps shorter than 20 days, the dynamic interpolation is extremely efficient and allows for the reconstruction of the time evolution of small mesoscale eddies (below 100 km) that would be smoothed out by conventional methods based on optimal mapping. Such a simple approach offers some perspectives for...
Tipo: Text
Palavras-chave: : Conservation equations; Eddies; Mesoscale processes; Mesoscale forecasting; Interpolation schemes; Quasigeostrophic models.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00252/36313/34865.pdf

Mesoscale Eddies Structure Mesopelagic Communities
Provedor de dados: 5
Autores: Della Penna, Alice; Gaube, Peter.
Mesoscale eddies play a key role in structuring open ocean ecosystems, affecting the entire trophic web from primary producers to large pelagic predators including sharks and elephant seals. Recent advances in the tracking of pelagic predators have revealed that these animals forage in the mesopelagic and the depth and duration of their foraging dives are affected by the presence of eddies. The ways in which eddies impact the distribution of mesopelagic micronekton, however, remain largely unknown. During a multi-seasonal experiment we used a shipboard scientific echosounder transmitting at 38 kHz to observe the distribution of acoustic backscattering in the energetic mesoscale eddy field of the northwestern Atlantic. Observations were collected at 24...
Tipo: Text
Palavras-chave: NAAMES; North Atlantic Aerosols and Ecosystems Study; Micronekton; Mesoscale; Eddies; Echosounder; Bioacoustics; Intermediate trophic levels.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00642/75390/76187.pdf

Observations of Irminger Sea Anticyclonic Eddies
Provedor de dados: 5
Autores: Fan, Xue; Send, Uwe; Testor, Pierre; Karstensen, Johannes; Lherminier, Pascale.
Mesoscale anticyclonic eddies in the Irminger Sea are observed using a mooring and a glider. Between 2002 and 2009, the mooring observed 53 anticyclones. Using a kinematic model, objective estimates of eddy length scales and velocity structure are made for 16 eddies. Anticyclones had a mean core diameter of 12 km, and their mean peak observed azimuthal speed was 0.1 m s(-1). They had core salinities and potential temperatures of 34.91-34.98 and 4.488-5.34 degrees C, respectively, making them warm and salty features. These properties represent a typical salinity anomaly of 0.03 and a temperature anomaly of 0.28 degrees C from noneddy values. All eddies had small (&lt;&lt; 1) Rossby numbers. In 2006, the glider observed two anticyclones having diameters of...
Tipo: Text
Palavras-chave: North Atlantic Ocean; Eddies; Mesoscale processes.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00137/24832/22921.pdf

Multiscale Observations of Deep Convection in the Northwestern Mediterranean Sea During Winter 2012-2013 Using Multiple Platforms
Provedor de dados: 5
Autores: Testor, Pierre; Bosse, Anthony; Houpert, Loic; Margirier, Felix; Mortier, Laurent; Legoff, Herve; Dausse, Denis; Labaste, Matthieu; Karstensen, Johannes; Hayes, Daniel; Olita, Antonio; Ribotti, Alberto; Schroeder, Katrin; Chiggiato, Jacopo; Onken, Reiner; Heslop, Emma; Mourre, Baptiste; D'Ortenzio, Fabrizio; Mayot, Nicolas; Lavigne, Heloise; De Fommervault, Orens; Coppola, Laurent; Prieur, Louis; Taillandier, Vincent; De Madron, Xavier Durrieu; Bourrin, Francois; Many, Gael; Damien, Pierre; Estournel, Claude; Marsaleix, Patrick; Taupier-letage, Isabelle; Raimbault, Patrick; Waldman, Robin; Bouin, Marie-noelle; Giordani, Herve; Caniaux, Guy; Somot, Samuel; Ducrocq, Veronique; Conan, Pascal.
During winter 2012-2013, open-ocean deep convection which is a major driver for the thermohaline circulation and ventilation of the ocean, occurred in the Gulf of Lions (Northwestern Mediterranean Sea) and has been thoroughly documented thanks in particular to the deployment of several gliders, Argo profiling floats, several dedicated ship cruises, and a mooring array during a period of about a year. Thanks to these intense observational efforts, we show that deep convection reached the bottom in winter early in February 2013 in a area of maximum 28±3 109m9. We present new quantitative results with estimates of heat and salt content at the sub-basin scale at different time scales (on the seasonal scale to a ten days basis) through optimal interpolation...
Tipo: Text
Palavras-chave: Ocean observation; Oceanic deep convection; Mediterranean Sea; Energy and buoyancy fluxes; Eddies; Plumes; Symmetric instability.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00415/52639/53494.pdf

Structure and Temporal Variability of Mediterranean Water in Hydrological and Marine Seismic Data South of Portimao Canyon (Gulf of Cadiz), from 1999 to 2002
Provedor de dados: 5
Autores: Quentel, Elise; Carton, Xavier; Gutscher, Marc-andre.
Hydrological and marine seismic data, collected in the Gulf of Cadiz (respectively in July 1999, 2000, 2001 and 2002, and in April 2000 and 2001) are analysed to reveal the various structures of Mediterranean Water (MW). Both the hydrological and seismic data clearly identify the MW undercurrents on the Iberian slope, detached MW eddies (meddies and a cyclone) and smaller fragments of MW (filaments and small eddies). Seismic reflectivity and synthetic reflectivity computed from hydrology, indicate that strong acoustic reflectors, associated with 8 - 64 m thick homogeneous water layers, are found above and below meddies and filaments, around the MW undercurrents, but mostly in the lower part of cyclones and below submesoscale eddies. Reflectors are also...
Tipo: Text
Palavras-chave: Mediterranean Water; Eddies; Undercurrent; Layering; Hydrological Data; Seismic Reflectivity; Submesoscale Structures.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00129/24006/21962.pdf

Overview of (Sub)mesoscale Ocean Dynamics for the NAAMES Field Program
Provedor de dados: 5
Autores: Della Penna, Alice; Gaube, Peter.
Tipo: Text
Palavras-chave: Mesoscale; Eddies; North Atlantic aerosols and marine ecosystems study; North Atlantic; NAAMES; Altimeter; Satellite oceanography; Lagrangian reanalysis.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00509/62022/66142.pdf

The Eddy Experiment: GNSS-R speculometry for directional sea-roughness retrieval from low altitude aircraft - art. no. L21307
Provedor de dados: 5
Autores: Germain, O; Ruffini, Giulio; Soulat, F; Caparrini, M; Chapron, Bertrand; Silvestrin, P.
We report the retrieval of sea surface directional mean square slope from Global Navigation Satellite System Reflections (GNSS-R) Delay-Doppler-Map (DDM) data collected during an experimental flight at 1 km altitude. We emphasize the utilization of the entire DDM to more precisely infer ocean roughness directional parameters, and argue that the DDM exhibits the impact of both roughness and scatterer velocity. Obtained estimates are analyzed and compared with Jason-1 measurements, ECMWF numerical weather model outputs and optical data.
Tipo: Text
Palavras-chave: Numerical model; Velocity; Sea surface roughness; Eddies; Delay Doppler Map; Remote sensing; Oceanography.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-749.pdf

Cyclones and Anticyclones in Seismic Imaging
Provedor de dados: 5
Autores: Barbosa Aguiar, A. C.; Menesguen, Claire; Le Gentil, Sylvie; Schopp, Richard; Carton, Xavier.
Nearly all the subsurface eddies detected in seismic imaging of sections in the northeast Atlantic have been assumed to be anticyclones containing Mediterranean Water (MW). Fewer MW cyclones have been observed and studied. In this study, the work of previous numerical studies is extended to investigate some characteristics of layering surrounding MW cyclones, using a primitive equation model with equal diffusivities for salinity and temperature to suppress the effects of double diffusion. It is shown that, after a stable state is reached, both anticyclones and cyclones display similar patterns of layering: stacked thin layers of high acoustic reflectivity located above and below the core of each vortex, which do not match isopycnals. The authors conclude...
Tipo: Text
Palavras-chave: Geographic location/entity; North Atlantic Ocean; Circulation/ Dynamics; Small scale processes; Atm/Ocean Structure/ Phenomena; Eddies; Vortices; Observational techniques and algorithms; Acoustic measurements/effects; Models and modeling; Primitive equations model.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00281/39190/37746.pdf

Monitoring of a quasi-stationary eddy in the Bay of Biscay by means of satellite, in situ and model results
Provedor de dados: 5
Autores: Caballero, Ainhoa; Ferrer, Luis; Rubio, Anna; Charria, Guillaume; Taylor, Benjamin H.; Grima, Nicolas.
The presence of a quasi-stationary anticyclonic eddy within the southeastern Bay of Biscay (centred around 44°30′N-4°W) has been reported on various occasions in the bibliography. The analysis made in this study for the period 2003–2010, by using in situ and remote sensing measurements and model results shows that this mesoscale coherent structure is present almost every year from the end of winter-beginning of spring, to the beginning of fall. During this period it remains in an area limited to the east by the Landes Plateau, to the west by Le Danois Bank and Torrelavega canyon and to the northwest by the Jovellanos seamount. All the observations and analysis made in this contribution, suggest that this structure is generated between Capbreton and...
Tipo: Text
Palavras-chave: Bay of Biscay; Eddies; SWODDIES; Topographic effects; Vortex; Mesoscale; Altimetry; Satellite oceanography; Drifters; ROMS.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00161/27260/25469.pdf

Heat balance in the Nordic Seas in a global 1/12° coupled model
Provedor de dados: 5
Autores: Treguier, Anne-marie; Mathiot, Pierre; Graham, Tim; Copsey, Dan; Lique, Camille; Sterlin, Jean.
The Nordic Seas are a gateway to the Arctic Ocean, where Atlantic water undergoes a strong cooling during its transit. Here we investigate the heat balance of these regions in the high resolution Met Office Global Coupled Model GC3 with a 1/12_ grid. The GC3 model reproduces resolution Met Office Global Coupled Model GC3 with a 1/12_ grid. The GC3 model reproduces the contrasted ice conditions and ocean heat loss between the eastern and western regions of the Nordic Seas. In the west (Greenland and Iceland seas), the heat loss experienced by the ocean is stronger than the atmospheric heat gain, because of the cooling by ice melt. The latter is a major contribution to the heat loss over the path of the East Greenland Current and west of Svalbard. In the...
Tipo: Text
Palavras-chave: Arctic; Atmosphere-ocean interaction; Ocean dynamics; Eddies; Climate models; Oceanic variability.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00654/76590/77739.pdf

Circulation around La Reunion and Mauritius islands in the south-western Indian Ocean: A modeling perspective
Provedor de dados: 5
Autores: Pous, Stephane; Lazure, Pascal; Andre, Gael; Dumas, Franck; Halo, Issufo; Penven, Pierrick.
Circulation around both islands is dominated by westward propagating features The predominant time scale of variability of currents and SSH is 60 days There is local generation of eddies in the lee of the islands due to topography
Tipo: Text
Palavras-chave: Ocean circulation; Hydrodynamic model; La Reunion; Eddies; Rossby waves.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00195/30624/29073.pdf

Reconstructing Upper Ocean Vertical Velocity Field from Sea Surface Height in the Presence of Unbalanced Motion
Provedor de dados: 5
Autores: Qiu, Bo; Chen, Shuiming; Klein, Patrice; Torres, Hector; Wang, Jinbo; Fu, Lee-lueng; Menemenlis, Dimitris.
Reconstructability of upper ocean vertical velocity (w) and vorticity (ζ) fields from high-resolution sea surface height (SSH) data is explored using the global 1/48° horizontal-resolution MITgcm output in the context of the forth-coming Surface Water and Ocean Topography (SWOT) mission. By decomposing w with an omega equation of the primitive-equation system and by taking into account the measurement design of the SWOT mission, this study seeks to reconstruct the subinertial, balanced w and ζ signals. By adopting the effective surface quasi-geostrophic (eSQG) framework and applying to the Kuroshio Extension region of the North Pacific, we find that the target and reconstructed fields have a spatial correlation of ~0.7 below the mixed layer for w and 0.7 ~...
Tipo: Text
Palavras-chave: Eddies; Mesoscale processes; Ocean dynamics; Vertical motion; Altimetry.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00593/70561/68744.pdf

A seasonal dipolar eddy near Ras Al Hamra (Sea of Oman)
Provedor de dados: 5
Autores: L'Hegaret, Pierre; Lacour, Leo; Carton, Xavier; Roullet, Guillaume; Baraille, Remy; Correard, Stephanie.
Trajectories and hydrological data from two Argo floats indicate that warm and salty water at 200–300-m depths was ejected from the coast of Oman, near Ras al Hamra, in spring 2008, 2011, and 2012. This warm and salty water, Persian Gulf Water (PGW), once ejected from the coast, recirculated cyclonically in the western Sea of Oman, but also flowed eastward along the Iranian and Pakistani coasts. There, it was expelled seaward by mesoscale eddies as shown by other float data. Seasonal maps of salinity were computed from all available Argo floats; they showed that, in spring, PGW is present in the middle and north of the Sea of Oman, contrary to fall, when the salinity maxima lie southeast of Ras al Hadd. The ejection of PGW from Ras al Hamra is related here...
Tipo: Text
Palavras-chave: Sea of Oman; Outflow; Eddies; Argo floats.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00171/28206/33894.pdf

Can We Infer Diapycnal Mixing Rates from the World Ocean Temperature-Salinity Distribution?
Provedor de dados: 5
Autores: Arzel, Olivier; Colin De Verdiere, Alain.
The turbulent diapycnal mixing in the ocean is currently obtained from microstructure and finestructure measurements, dye experiments, and inverse models. This study presents a new method that infers the diapycnal mixing from low-resolution numerical calculations of the World Ocean whose temperatures and salinities are restored to the climatology. At the difference of robust general circulation ocean models, diapycnal diffusion is not prescribed but inferred. At steady state the buoyancy equation shows an equilibrium between the large-scale diapycnal advection and the restoring terms that take the place of the divergence of eddy buoyancy fluxes. The geography of the diapycnal flow reveals a strong regional variability of water mass transformations....
Tipo: Text
Palavras-chave: Diapycnal mixing; Eddies; Meridional overturning circulation; Mixing; Ocean circulation; General circulation models.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00600/71197/69563.pdf

Dynamics of an Equatorial River Plume: Theory and Numerical Experiments Applied to the Congo Plume Case
Provedor de dados: 5
Autores: Vic, Clement; Berger, Henrick; Treguier, Anne-marie; Couvelard, Xavier.
The Congo River has the second largest rate of flow in the world and is mainly responsible for the broad tongue of low-salinity water that is observed in the Gulf of Guinea. Despite their importance, near-equatorial river plumes have not been studied as thoroughly as midlatitude plumes and their dynamics remain unclear. Using both theory and idealized numerical experiments that reproduce the major characteristics of the region, the authors have investigated the dynamics of the Congo River plume and examine its sensitivity to different forcing mechanisms. It is found that near-equatorial plumes are more likely to be surface trapped than midlatitude plumes, and the importance of the effect in describing the strong offshore extent of the low-salinity tongue...
Tipo: Text
Palavras-chave: Geographic location; Entity; Rivers; Circulation; Dynamics; Coastal flows; Density currents; Eddies; Nonlinear dynamics; Topographic effects.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00187/29850/28298.pdf