Circulation in the Alboran Sea as Determined by Quasi-Synoptic Hydrographic Observations. Part I: Three-Dimensional Structure of the Two Anticyclonic Gyres

Viúdez, Álvaro; Tintoré, Joaquı́n; Haney, Robert L.

doi:10.1175/1520-0485(1996)026<0684:citasa>2.0.co;2

Cited by 116 publications

(87 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following previous observational studies (Leach 1987, Tintoré et al 1991, Pollard and Regier 1992, Fiekas et al 1994, Viúdez et al 1996a, Allen and Smeed 1996, Rudnick 1996and Shearman et al 1999) and modelling studies (Strass 1994, Pinot et al 1996 we have used the QG form of the omega equation (Hoskins et al, 1978) to diagnose the vertical velocity field for each FSS. On an β -plane, and for timescales at which the effects of diffusion can be considered negligible, this equation can be written as…”

Section: ) Vertical Velocitiesmentioning

confidence: 91%

Mesoscale subduction at the Almeria–Oran front

Allen

Smeed

Tintoré

et al. 2001

Journal of Marine Systems

View full text Add to dashboard Cite

This paper presents a detailed diagnostic analysis of hydrographic and current meter data from three, rapidly repeated, fine-scale surveys of the Almeria-Oran front.Instability of the frontal boundary, between surface waters of Atlantic and Mediterranean origin, is shown to provide a mechanism for significant heat transfer from the surface layers to the deep ocean in winter. The data were collected during the second observational phase of the EU funded OMEGA project on RRS Discovery cruise 224 during December 1996. High resolution hydrographic measurements using the towed undulating CTD vehicle, SeaSoar,. traced the subduction of Mediterranean Surface Water across the Almeria-Oran front. This subduction is shown to result from a significant baroclinic component to the instability of the frontal jet. The Qvector formulation of the omega equation is combined with a scale analysis to quantitatively diagnose vertical transport resulting from mesoscale ageostrophic circulation. The analyses are presented and discussed in the presence of satellite and airborne remotely sensed data; which provide the basis for a thorough and novel approach to the determination of observational error.

show abstract

Section: ) Vertical Velocitiesmentioning

confidence: 91%

Mesoscale subduction at the Almeria–Oran front

Allen

Smeed

Tintoré

et al. 2001

Journal of Marine Systems

View full text Add to dashboard Cite

show abstract

“…However, the integration of the thermal wind equation is subject to the choice of a reference level where the pressure field is known: this choice is not obvious, especially in the Mediterranean sea, where one can distinguish several water masses in the vertical (Tchernia, 1977;La Violette, 1994;Beckers et al, 1997). The vertical extension of the Western Alboran Gyre (WAG) is of the order of 200-220 m as shown by Viúdez et al (1996), and they chose a reference level of 200 and 300 m. This is not surprising, since the approximate level that separates eastward flowing Atlantic Water (AW) from westward flowing Mediterranean Water (MW) is found to be at 200 -250 m. So we may expect low velocities at these depths, at least for the special case of the Alboran Sea. To validate this first estimate of the level of no-motion, we used several measures (OuÁjTO, OuÁjSO,.…”

Section: The Geostrophic Equilibriummentioning

confidence: 84%

“…An example is the calculation of the vertical velocity from the analysed T,S fields by means of the diagnostic OMEGA equation which is known to react strongly to changes in the data and in the analysis (e.g. Hoskins and Draghici, 1977;Hoskins et al, 1978;Tintoré et al, 1991;Pollard and Regier, 1992;Pinot et al, 1996;Viúdez et al, 1996;Allen and Smeed, 1996).…”

Section: Introductionmentioning

confidence: 98%

“…It is first worthwhile to mention that the terminology 'quasi-synoptic' or 'nonsynoptic data set' is used in several publications (e.g. Golnaraghi et al, 1996;Viúdez et al, 1996), pointing out the fact that, apart from mapping errors arising from poor-resolution samplings, some error contributions from space/time smearing of the ocean dynamics are also expected in the analysis. Matthews (1997) examines the impact of nonsynoptic sampling on mesoscale oceanographic surveys with towed instruments by using an isopycnal model: temporal changes in the model lead to a 40-50% increase in the RMS errors compared to those due to the spatial separation of the sampling points.…”

Section: Introductionmentioning

confidence: 99%

“…The distance between stations was usually 20V longitude ( f 30 km) and 10V latitude ( f 18 km). Vertical profiles were made down to 600 m except in coastal regions, with an interpolated accuracy of 1 m (Viúdez et al, 1996). Perkins et al (1990) estimate typical length scales of 20 -100 km in the Western Alboran Sea (WAS), whereas Gascard and Richez (1985) evaluate the internal Rossby radius in the Eastern Alboran Gyre (EAG) to 20 km.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A synopticity test of a sampling pattern in the Alboran Sea

Rixen¹,

Beckers²

2002

Journal of Marine Systems

View full text Add to dashboard Cite

Hydrographic surveys are usually considered as synoptic, as if the corresponding data set had been sampled at the same time. However, this assumption might lead to strong biases in subsequent analyses. To obtain synoptic data at a given moment, we integrate a Lagrangian motion equation towards a 'modal sampling time', to relocate the sampling stations both in time and space, by combining objective analysis and geostrophic velocities, assumed to be either stationary or unstationary over the period of integration. The relocation algorithms are applied to a data set covering the entire Alboran Sea. The relocation of data points leads to a significant change on vertical velocities computed with the OMEGA equation. For validation purpose, the algorithm is also applied to a synthetic data set obtained from a 3D Primitive Equation (PE) model output. Raw and pseudosynoptic analysed temperature -salinity (T/S) fields and derived quasigeostrophic (QG) vertical velocities are compared. It is shown that the relocation method might correct significantly the errors arising from the synopticity hypothesis and that the sensitivity to the level of no-motion and the analysis parameters is less important than the nonsynopticity. D

show abstract

Sea surface transport in the Western Mediterranean Sea: A Lagrangian perspective

Sayol

Orfila

Simarro³

et al. 2013

JGR Oceans

View full text Add to dashboard Cite

[2] We study the sea surface transport in the Western Mediterranean Sea from a Lagrangian point of view, in particular the Alboran and the North-Western subbasins. The study is carried out through the analysis of 3 years of surface velocity model data through Finite Size Lyapunov Exponents, Residence Time, and virtual particle trajectories complementing the classical Eulerian approach. The spatiotemporal variability of the main transport processes is inferred from the Empirical Orthogonal Function modes of the Lyapunov Exponents, being the most relevant modes discussed and physically interpreted. Results indicate that some of the variability in the surface transport patterns in the Western Mediterranean can be explained by specific modes which provide an indication of connectivity among subbasins, like the inflow of Atlantic waters through the Ibiza Channel.

show abstract

Circulation in the Alboran Sea as Determined by Quasi-Synoptic Hydrographic Observations. Part I: Three-Dimensional Structure of the Two Anticyclonic Gyres

Cited by 116 publications

References 0 publications

Mesoscale subduction at the Almeria–Oran front

Mesoscale subduction at the Almeria–Oran front

A synopticity test of a sampling pattern in the Alboran Sea

Sea surface transport in the Western Mediterranean Sea: A Lagrangian perspective

Contact Info

Product

Resources

About