Carton Xavier

Carton Xavier
Université de Bretagne Occidentale | UBO · Institut Universitaire Européen de la Mer (IUEM)

38.11
 · 
Professor

About

152
Publications
20,575
Reads
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2,754
Citations
Introduction
Our team works on outflows from marginal seas, on currents and eddies. We use theory, numerical modeling and data analysis. Our group of professors teach in the Master of Marine Sciences/Marine Physics. If you are interested in our work and teaching, please see https://www-iuem.univ-brest.fr/master_sml/en/specialties/marine-physics/presentation and https://www.umr-lops.fr/
Research Experience
September 2017 - present
Université de Bretagne Occidentale
Position
  • Professor (PREX2)
September 2011 - September 2013
Ecole Navale de Lanvéoc-Poulmic
Position
  • invited lecturer (fluid dynamics and oceanography)
September 2011 - present
ENSTA Bretagne
Position
  • invited lecturer (oceanography)
Education
June 1999 - June 1999
Université de Bretagne Occidentale
Field of study
  • Ocean and atmosphere dynamics
September 1985 - September 1988
Ecole Normale Supérieure de Paris
Field of study
  • Geophysical Fluid Dynamics, Dynamics of the atmosphere and oceans
September 1984 - September 1985
Sorbonne Université
Field of study
  • Physics and dynamics of the atmosphere and oceans

Publications

Publications (152)
Article
Full-text available
In this paper, we investigate the vortex–wall interaction on the β-plane, using a submesoscale and internal waves resolving model in an idealised context. Our results bring new insights on the dynamics of oceanic mesoscale eddies as they drift toward a western boundary. We show that there exists a strong cyclone/anticyclone asymmetry in the interac...
Article
Full-text available
Submesoscale coherent vortices (SCVs) are numerous in high resolution numerical simulations, but their observations are scarce. Among the few in situ available measurements of SCVs, a vast majority concern anticyclones. No cyclonic SCV with large dynamical Rossby number (|ζ/f|> 1) has ever been sampled. This suggested that such small cyclones may l...
Article
Full-text available
The Omani Coastal Current (OCC) flowing northward along the southern coast of Oman during the summer monsoon is associated with an upwelling system. The mesoscale circulation of the western Arabian Sea is dominated by energetic mesoscale eddies down to about 1000 m depth. They drive the pathways of the upwelling water masses and the Persian Gulf Ou...
Preprint
Full-text available
We investigate the surface and subsurface submesoscale dynamics in the Gulf of Aden and 1 the Gulf of Oman. Our results are based on the analyses of regional numerical simulations performed 2 with a primitive equation model (HYCOM) at submesoscale permitting horizontal resolution. A 3 model zoom for each gulf is embedded in a regional mesoscale-res...
Preprint
Full-text available
The Omani Coastal Current (OCC) flowing northward along the southern coast of Oman 1 during the summer monsoon, is associated with an upwelling system. The mesoscale circulation 2 of the western Arabian Sea is dominated by energetic mesoscale eddies down to about 1000 meters 3 depth. They drive the pathways of the upwelling water masses and the Per...
Preprint
Full-text available
The Red Sea Water enters the Gulf of Aden through the Strait of Bab El Mandeb as a density current. The Red Sea Water subsequently spreads into the Gulf of Aden under the influence of surface mesoscale eddies, which dominate the surface flow, of topographic features such as rift and capes, and of the monsoon regimes. The dynamics of a bottom densit...
Article
Full-text available
The Red Sea Water enters the Gulf of Aden through the Strait of Bab El Mandeb as a density current. The Red Sea Water subsequently spreads into the Gulf of Aden under the influence of surface mesoscale eddies, which dominate the surface flow, of topographic features such as rift and capes, and of the monsoon regimes. The dynamics of a bottom densit...
Article
Full-text available
Oceanic vortices are ubiquitous in the ocean. They dominate the sub-inertial energy spectrum, and their dynamics is key for the evolution of the water column properties. The merger of two like-signed coherent vortices, which ultimately results in the formation of a larger vortex, provides an efficient mechanism for the lateral mixing of water masse...
Article
Full-text available
In this study, we harness the 25-year satellite-altimeter record, in concert with a vast array of in situ measurements, to estimate the heat content anomaly of 32 warm-core rings in the Gulf of Mexico (GoM). The decay rate of these mesoscale eddies is studied in detail, and it is shown that they release the majority of their heat as they drift in t...
Article
Full-text available
The Red Sea Water is a warm and salty water produced in the Red Sea by evaporation induced by strong solar radiation. This dense water mass exits the Red Sea through the Strait of Bab El Mandeb, and enters the Gulf of Aden as a density current between 400 and 1000 meter depth. In the Gulf of Aden, in situ and satellites observations have shown the...
Article
Full-text available
Persian Gulf Water and Red Sea Water are salty and dense waters flowing at intermediate depths in the Gulf of Oman and the Gulf of Aden, respectively. Their spreading pathways are influence by mesoscale eddies that dominate the surface flow in both semi-enclosed basins. In situ measurements combined with altimetry indicate that Persian Gulf Water i...
Article
Full-text available
The Persian Gulf Water and Red Sea Water are salty and dense waters recirculating at subsurface in the Gulf of Oman and the Gulf of Aden respectively, under the influence of mesoscale eddies which dominate the surface flow in both semi-enclosed basins. In situ measurements combined with altimetry indicate that the Persian Gulf Water is driven by me...
Article
We consider the interaction between two quasi-geostrophic vortices of height-to-width aspect ratio h/r, lying at two different vertical levels. We investigate whether such structures naturally align. In the case the vortices occupy distinct yet contiguous vertical levels, such an alignment can contribute to the growth in volume of oceanic mesoscale...
Article
Full-text available
In the Arabian Sea, mesoscale eddies are prominent features of the circulation. They influence biological activities, tracer transport, and physical and chemical properties of the seawater. In particular, the pathways of salty water masses outflowing from the marginal seas are strongly impacted by the mesoscale eddies that evolve in the western par...
Poster
Full-text available
In the Northern Arabian Sea, the pathway of the salty Persian Gulf Water outflowing from the Persian Gulf is strongly impacted by the mesoscale and submesoscale features which evolve in the Sea of Oman and around the Arabian Peninsula. We use ARGO floats colocalized with eddies detected in the Arabian Sea for the period 2000-2015 from altimetric da...
Article
Full-text available
Deformation flows are the flows incorporating shear, strain and rotational components. These flows are ubiquitous in the geophysical flows, such as the ocean and atmosphere. They appear near almost any salience, such as isolated coherent structures (vortices and jets) and various fixed obstacles (submerged obstacles and continental boundaries). Flu...
Article
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The stability properties of a vortex lens are studied in the quasi geostrophic (QG) framework using the generalized stability theory. Optimal perturbations are obtained using a tangent linear QG model and its adjoint. Their fine-scale spatial structures are studied in details. Growth rates of optimal perturbations are shown to be extremely sensitiv...
Article
Full-text available
High-resolution hydrographic measurements reveal the presence of three intrathermocline eddies (ITEs) embedded within a loop current eddy. ITEs are lenticular bodies of nearly homogeneous water, which contrasts with the well-stratified surrounding water. Their radii and thickness ranged between 19–32 km and 150–250 m. Negative relative vorticity wi...
Article
Full-text available
We investigate families of finite core vortex quartets in mutual equilibrium in a two-layer quasigeostrophic flow. The finite core solutions stem from known solutions for discrete (singular) vortex quartets. Two vortices lie in the top layer and two vortices lie in the bottom layer. Two vortices have positive potential vorticity anomaly, while the two...
Article
Full-text available
Within the framework of the quasi-geostrophic approximation, the interactions of two identical initially circular vortex patches are studied using the contour dynamics/surgery method. The cases of barotropic vortices and of vortices in the upper layer of a two-layer fluid are considered. Diagrams showing the end states of vortex interactions and, i...
Article
This study evaluates the capability of eddy‐permitting regional ocean models to reproduce the interocean exchange south of Africa. In this highly turbulent region, we show that the vertical structure of the horizontal flows need to be appropriately resolved to realistically advect thermocline water‐masses into the South Atlantic. Our results point...
Article
Full-text available
We present a set of equations describing the nonlinear dynamics of flows constrained by environmental rotation and stratification (Rossby numbers Ro ∈ [ 0.1, 0.5 ] and Burger numbers of order unity). The fluid is assumed incompressible, adiabatic, inviscid and in hydrostatic balance. This set of equations is derived from the Navier Stokes equations...
Article
The turbulent processes in the Cape Basin, the southeasternmost gate of the Atlantic Ocean, play a key role in the transport and mixing of upper to intermediate water masses entering the area from the Indian Ocean, making them especially relevant for the Indo-Atlantic transfer of heat and salt. In this paper, two numerical simulations at different...
Article
Full-text available
A simple dynamical model of vortex interactions taking place near a curved boundary mimicking a circular bay is formulated and examined. An initial configuration consisting of a point vortex in the bay and of an incident point vortex moving toward the bay along the straight part of the boundary is considered. Both vortices are of equal strengths. T...
Article
We study the surface signatures of Mediterranean water eddies (Meddies) in the context of a regional, primitive equations model simulation (using the Regional Oceanic Modeling System, ROMS). This model simulation was previously performed to study the mean characteristics and pathways of Meddies during their evolution in the Atlantic Ocean. The adva...
Article
Full-text available
We study the influence of bottom topography on the interaction of two identical vortices in a two-layer, quasi-geostrophic model. The two vortices have piecewise-uniform potential vorticity and are lying in the upper layer of the model. The topography is a smooth bottom slope. For two cyclones, topography modifies the merger critical distance and t...
Article
Full-text available
The effect of a bottom slope on the merger of two identical Rankine vortices is investigated in a two-dimensional, quasi-geostrophic, incompressible fluid. When two cyclones initially lie parallel to the slope, and more than two vortex diameters away from the slope, the critical merger distance is unchanged. When the cyclones are closer to the slope,...
Article
Full-text available
The Lofoten Vortex (LV), a quasi-permanent anticyclonic eddy in the Lofoten Basin of the Norwegian Sea, is investigated with an eddy-permitting primitive equation model nested into the ECCO2 ocean state estimate. The LV, as simulated by the model, extends from the sea surface to the ocean bottom at about 3000 m and has the subsurface core between 5...
Article
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This paper addresses the dynamical coupling of the ocean’s surface and the ocean’s interior. In particular, we investigate the dynamics of an oceanic surface jet and its interaction with vortices at depth. The jet is induced by buoyancy (density) anomalies at the surface. We first focus on the jet alone. The linear stability indicates there are two...
Article
Full-text available
This paper focuses on the nonlinear interaction between a surface quasi-geostrophic buoyancy filament and an internal vortex. We first revisit the stability of an isolated buoyancy filament. The buoyancy profile considered is continuous and leads to a continuous velocity field, albeit one with infinite shear just outside its edge. The stability pro...
Article
Full-text available
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 exist...
Article
Full-text available
We investigate equilibrium solutions for tripolar vortices in a two-layer quasi-geostrophic flow. Two of the vortices are like-signed and lie in one layer. An opposite-signed vortex lies in the other layer. The families of equilibria can be spanned by the distance (called separation) between the two like-signed vortices. Two equilibrium configuration...
Article
Full-text available
This paper focuses on the nonlinear interaction between a surface quasi-geostrophic buoyancy filament and an internal vortex. We first revisit the stability of an isolated buoyancy filament. The buoyancy profile considered is continuous and leads to a continuous velocity field, albeit one with infinite shear just outside its edge. The stability pro...
Article
Full-text available
The vertical thermohaline and biogeochemical structures of the upper layer (0-200 m) were studied in the Gulf of Tadjourah using high-resolution hydrographic data collected in July-August 2013, September 2013 and February 2014. During summer, the superficial layer consisted of the mixed layer (ML) extending to a depth of about 20-30 m followed by t...
Article
Full-text available
The Persian Gulf produces high-salinity water (Persian Gulf Water, PGW hereafter), which flows into the Sea of Oman via the Strait of Hormuz. Beyond the Strait of Hormuz, the PGW cascades down the continental slope and spreads in the Sea of Oman under the influence of the energetic mesoscale eddies. The PGW outflow has different thermohaline charac...
Article
Full-text available
In this study, we first show that it is difficult to reconstruct the vertical structure of vortices using only surface observations. In particular we show that the recent SQG and ISQG methods systematically lead to surface intensified vortices and those subsurface intensified vortices are thus not correctly modelled. We then investigate the possibi...
Article
Full-text available
We investigate numerically the nonlinear interactions between hetons. Hetons are baroclinic structures consisting of two vortices of opposite sign lying at different depths. Hetons are long-lived. They most often translate (they can sometimes rotate) and therefore they can noticeably contribute to the transport of scalar properties in the oceans. H...
Article
Full-text available
This study focuses on the interaction between mid depth vortices and surface jets and fronts in a three-layer quasi-geostrophic model. Such vortices may be regarded as an idealisation of meddies, eddies of Mediterranean Water in the Northeastern Atlantic Ocean, interacting with the Azores j t and front. Successively, a single vortex, a vortex doubl...
Article
Full-text available
The merger of two identical surface temperature vortices is studied in the surface quasi-geostrophic model. The motivation for this study is the observation of the merger of submesoscale vortices in the ocean. Firstly, the interaction between two point vortices, in the absence or in the presence of an external deformation field, is investigated. Th...
Article
Vortex merger is a phenomenon characterizing the whole class of geophysical vortices, from atmospheric storms and large oceanic eddies up to small scale turbulence. Here we focus on the merger of subsurface oceanic anticyclones in an idealized primitive equations model. This study has been motivated by past and recent observations of colliding lens...
Article
Full-text available
Hetons are baroclinic vortices able to transport tracers or species, which have been observed at sea. This paper studies the offset collision of two identical hetons, often resulting in the formation of a baroclinic tripole, in a continuously stratified quasi-geostrophic model. This process is of interest since it (temporarily or definitely) stops...
Article
Full-text available
Nearly all the sub-surface eddies detected in seismic imaging of sections in the North East Atlantic have been assumed to be anticyclones containing Mediterranean Water (MW). Fewer MW cyclones have been observed and studied. In this study we extend the work of previous numerical studies to investigate some characteristics of layering surrounding MW...
Article
Full-text available
Abstract We study the influence of deep vortices on the ocean surface both in terms of elevation and of temperature, both of which being related to the stream function. We use several mathematical and numerical models to go from the most idealized configurations (point vortices) to realistic ones (finite volume vortices). We determine analytically...
Article
The Persian Gulf feeds a warm and salty outflow in the Gulf of Oman (northern Arabian Sea). The salt climatological distribution is relatively smooth in the Gulf of Oman, and the signature of a slope current carrying salty waters is difficult to distinguish hundreds of kilometers past the Strait of Hormuz, in contrast to other outflows of the world...
Article
Full-text available
The Arabian Sea and Sea of Oman circulation and water masses, subject to monsoon forcing, reveal a strong seasonal variability and intense mesoscale features. We describe and analyze this variability and these features, using both meteorological data (from ECMWF reanalyses), in situ observations (from the ARGO float program and the GDEM – Generaliz...
Article
Full-text available
We examine the interactions between two three-dimensional quasi-geostrophic hetons. The hetons are initially translating towards one another. We address the effect of the vertical distance between the two poles (vortices) constituting each heton on the interaction. We also examine the influence of the horizontal separation between the poles within...
Article
Full-text available
Data from ship vertical casts (NODC data-set), ARGO profiling floats (Coriolis data-set) and RAFOS-type neutral density floats (WOCE data-set) are used to study characteristics of meddies in the Northeast Atlantic. In total 241 Mediterranean Water eddies (meddies) and 236 parts of float trajectories within meddies are selected for detailed analysis...
Article
The so-called carousel tripoles are constructed and characterized in the framework of two-layer quasi-geostrophic contour dynamics, and their stability is examined. Such a tripole is a steadily rotating doubly symmetric ensemble of three collinear vortices, or more specifically, uniform-potential-vorticity patches, with the central, core vortex, lo...
Article
Full-text available
The present study defines new interpolation functions for hydrological data. These functions are applied to generate climatological maps of temperature–salinity distribution with a 25 m depth interval and a 30 km space interval (MEDTRANS data set). The data undergo rigorous initial data quality control, having passed several filtering procedures. T...
Article
We use cross-slope sections of direct current observations together with a high resolution numerical simulation to revisit estimates of transports and entrainment in the Gulf of Cadiz. We provide a three dimensional picture of the outflow from the Mediterranean into the intermediate layers of the Atlantic.In the model, the time-averaged Mediterrane...
Article
Full-text available
Previous studies modeling the circulation and thermohaline structure in the Persian Gulf have suggested that interannual variability and vertical mixing processes could explain the model biases when compared to the few observations available. Here, a realistic, interannual, high-resolution model of the Persian Gulf is presented, validated against o...
Conference Paper
Full-text available
In this numerical process study, we examine the impact of the relative positions of a coastal current and the continental slope on the dynamics of a planktonic ecosystem. In the open ocean, previous studies have evidenced the importance of mesoscale and submesoscale turbulence on the structure and functioning of planktonic ecosystem (Rivière et Pon...
Article
Full-text available
The stability of circular vortices to normal mode perturbations is studied in a multi-layer quasi-geostrophic model. The stratification is fitted on the Gulf of Cadiz where many Mediterranean Water (MW) eddies are generated. Observations of MW eddies are used to determine the parameters of the reference experiment; sensitivity tests are conducted a...
Article
Full-text available
In this work we obtain new results on the manifestation of meddies (or of other deep eddies) at the sea-surface, further developing the results by Bashmachnikov and Carton [2012]. The quasi-geostrophic equations are used to describe a near-axisymmetric vortex in the upper ocean, forced at its lower boundary by the isopycnal elevation of a moving me...
Article
We describe surface anticyclones developing in summer time after persistent Levanter (i.e., easterly) gap winds in the Gulf of Cadiz. The process of generation of these eddies is similar to those formed in the tropical Pacific eastern margin in many aspects, but their evolution and fate is different. The anticyclones are surface intensified structu...
Article
Dissolved cobalt (DCo; < 0.2μm; 14 to 93 pM) and the apparent particulate cobalt (PCo; > 0.2μm; < 1 to 15 pM) were determined in the upper water-column (< 1000 m) of the Western Atlantic Ocean along the GEOTRACES-A02 section (64°N to 50°S). The lowest DCo concentrations, typical of a nutrient-type distribution were observed in surface waters of the...
Article
The Great Whirl (GW) is a persistent anticyclonic mesoscale eddy that is observed seasonally in the Arabian Sea during a period embedding the three months of the southwest monsoon (June-July-August) at a quasi-steady location. Its dynamics remain unclear despite it being one of the largest coherent vortices in the world ocean. Realistic regional nu...
Article
A collision of Mediterranean Water dipoles in the Gulf of Cadiz is studied here, using data from the MedTop and Semane experiments. First, a Mediterranean Water eddy (meddy) was surveyed hydrologically in November 2000 southwest of Cape Saint Vincent. Then, this meddy drifted northeastward from this position, accompanied by a cyclone (detected only...
Article
Full-text available
We investigate the stability of a steplike Rankine vortex in a one-active-layer, reduced gravity, quasi-geostrophic model. After calculating the linear stability with a normal mode analysis, the singular modes are determined as a function of the vortex shape to investigate short-time stability. Finally we determine the position of the critical laye...