Editorial Type:
Article
Article Type:
Research Article

The Deflection and Division of an Oceanic Baroclinic Jet by a Coastal Boundary: A Case Study in the Alboran Sea

Álvaro Viúdez Department of Meteorology, Naval Postgraduate School, Monterey, California

Search for other papers by Álvaro Viúdez in
Current site
Google Scholar
PubMed Close
,
Robert L. Haney Department of Meteorology, Naval Postgraduate School, Monterey, California

Search for other papers by Robert L. Haney in
Current site
Google Scholar
PubMed Close
, and
Jorge Vázquez-Cuervo Jet Propulsion Laboratory, Pasadena, California

Search for other papers by Jorge Vázquez-Cuervo in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Feb 1998
DOI:
https://doi.org/10.1175/1520-0485(1998)028<0289:TDADOA>2.0.CO;2
Page(s):
289–308
Restricted access

Abstract

An oceanic baroclinic jet impinging on a coastal boundary represents a particular type of ocean–coast interaction. This specific oceanographic phenomenon is an example of the stagnation in line flows occurring in fluid dynamics with three additional features: rotation, stratification, and a sloping boundary. In this study the authors describe the density, vorticity, and deformation characteristics of an oceanic jet impinging on a sloping boundary. The case study corresponds to the impinging process of the Atlantic jet at the African coast (Alboran Sea).

In the impinging region, the acceleration field is divergent related to the fact that the magnitude of the deformation is larger than the magnitude of the rotation. It is also found that the stagnation streamsurface does not lie in a vertical plane but tilts in the opposite direction to the tilt of the isopycnals. The flow upstream of the stagnation point is characterized by backing, speed convergence, diffluence, and negative streamwise vorticity. The flow past the stagnation point is characterized by veering, speed divergence, confluence, and positive streamwise vorticity. The current can only be considered irrotational in a narrow part of the impinging region.

* Current affiliation: Departament de Física, Universitat de les Illes Balears, Palma de Mallorca, Spain.

Corresponding author address: Álvaro Viúdez, Departament de Física, Universitat de les Illes Balears, 07071—Palma de Mallorca, Spain.

Abstract

An oceanic baroclinic jet impinging on a coastal boundary represents a particular type of ocean–coast interaction. This specific oceanographic phenomenon is an example of the stagnation in line flows occurring in fluid dynamics with three additional features: rotation, stratification, and a sloping boundary. In this study the authors describe the density, vorticity, and deformation characteristics of an oceanic jet impinging on a sloping boundary. The case study corresponds to the impinging process of the Atlantic jet at the African coast (Alboran Sea).

In the impinging region, the acceleration field is divergent related to the fact that the magnitude of the deformation is larger than the magnitude of the rotation. It is also found that the stagnation streamsurface does not lie in a vertical plane but tilts in the opposite direction to the tilt of the isopycnals. The flow upstream of the stagnation point is characterized by backing, speed convergence, diffluence, and negative streamwise vorticity. The flow past the stagnation point is characterized by veering, speed divergence, confluence, and positive streamwise vorticity. The current can only be considered irrotational in a narrow part of the impinging region.

* Current affiliation: Departament de Física, Universitat de les Illes Balears, Palma de Mallorca, Spain.

Corresponding author address: Álvaro Viúdez, Departament de Física, Universitat de les Illes Balears, 07071—Palma de Mallorca, Spain.

Save
Cover Journal of Physical Oceanography
Journal of Physical Oceanography

  • Ayoub, N., P. Y. Le Traon, and P. De Mey, 1997: A description of the Mediterranean surface variable circulation from combined ERS-1 and TOPEX/POSEIDON altimetric data. J. Mar. Syst., in press.

  • Batchelor, G. K., 1970: An Introduction to Fluid Dynamics. Cambridge University Press, 615 pp.

  • Bjørgum, O., 1951: On Beltrami vector fields and flows. Part I. Universitet J. Bergen, Naturvitenskapalig rekke, No. 1, 1–85.

  • Brandes, E. A., R. P. Davies-Jones, and B. C. Johnson, 1988: Streamwise vorticity effects on supercell morphology and persistence. J. Atmos. Sci.,45, 947–963.

  • Bucca, P. J., and T. H. Kinder, 1984: An example of meteorological effects on the Alboran Sea gyre. J. Geophys. Res.,89, 751–757.

  • Cano, N., 1978: Hidrología del Mar de Alborán en primavera-verano. Bol. Inst. Esp. Oceanogr.,248, 51–66.

  • Chadwick, P., 1976: Continuum Mechanics. Wiley, 174 pp.

  • Churchill, S. W., 1988: Viscous Flows: The Practical Use of Theory. Butterworth, 602 pp.

  • Conlon, D. M., 1982: On the outflow mode of the Tsugaru Warm Current. La Mer,10, 60–64.

  • Davies-Jones, R., 1984: Streamwise vorticity: The origin of updraft rotation in supercell storms. J. Atmos. Sci.,41, 2991–3006.

  • ——, 1991: The frontogenetical forcing of secondary circulations. Part I: The duality and generalization of the Q vector. J. Atmos. Sci.,48, 497–509.

  • Dhanak, M. R., and J. T. Stuart, 1995: Distorsion of the stagnation-point flow due to cross-stream vorticity in the external flow. Philos. Trans. Roy. Soc. London, A, 352, 443–452.

  • Dorrepaal, J. M., 1986: An exact solution of the Navier-Stokes equation which describes non-orthogonal stagnation-point flow in two dimensions. J. Fluid Mech.,163, 141–147.

  • Ericksen, J. L., 1960: Tensor fields. Handbuch der Physik III/I, S. Flügge, Ed., Springer-Verlag, 794–858.

  • Fedorov, A. V., and W. K. Melville, 1996: Hydraulic jumps at boundaries in rotating fluids. J. Fluid Mech.,324, 55–82.

  • Ferri, A., and P. A. Libby, 1954: Note on an interaction between the boundary layer and the inviscid flow. J. Aeronaut. Sci.,21, 130.

  • García-Lafuente, J., N. Cano, M. Vargas, J. P. Rubín, and A. Hernández-Guerra, 1997: Evolution of the Alboran Sea hydrographic structures during July 1993. Deep-Sea Res., in press.

  • Gascard, J. C., and C. Richez, 1985: Water masses and circulation in the western Alboran Sea and in the Straits of Gibraltar. Progress in Oceanography, Vol. 15, Pergamon Press, 157–216.

  • Gluert, M. B., 1957: The boundary layer in simple shear flow past a flat plate. J. Aeronaut. Sci.,24, 848–849.

  • Godske, C. L., T. Bergeron, J. Bjerknes, and R. C. Bundgaard, 1957:Dynamic Meteorology and Weather Forecasting. Amer. Meteor. Soc. and Carnegie Institute, 800 pp.

  • Gola̧b, S., 1974: Tensor Calculus. Elsevier, 371 pp.

  • Gurtin, M., 1981: An Introduction to Continuum Mechanics. Academic Press, 265 pp.

  • Haney, R. L., 1974: A numerical study of the response of an idealized ocean to large-scale surface heat and momentum flux. J. Phys. Oceanogr.,4, 145–167.

  • ——, 1985: Midlatitude sea surface temperature anomalies: A numerical hindcast. J. Phys. Oceanogr.,15, 787–799.

  • Hawthorne, W. R., 1951: Secondary circulation in fluid flow. Proc. Roy. Soc. London Ser. A, 206, 374–387.

  • ——, and M. E. Martin, 1955: The effect of density gradient and shear on the flow over a hemisphere. Proc. Roy. Soc. London Ser. A, 232, 184–195.

  • Heburn, G. W., and P. E. La Violette, 1990: Variations in the structure of the anticyclonic gyres found in the Alboran Sea. J. Geophys. Res.,95, 1599–1613.

  • Hiemenz, K., 1911: Die Grenzschicht an einem in den gleichförmigen Flüssigkeitsstrom eingetauchten geraden Kreiszylinder. Ph.D. dissertation, Göttingen and Dingl. Polytech. J.

  • Higuera, F. J., 1994: The hydraulic jump in a viscous laminar flow. J. Fluid Mech.,274, 69–92.

  • Hollmann, G., 1958: Die Krümmungs- und die Scherungs-Vorticitygleichung; Die Richtungs- und die Geschwindigkeits-Divergenzgleichung. Beitr. Phys. Atmos.,30, 254–267.

  • Hoskins, B. J., 1975: The geostrophic momentum approximation and the semi-geostrophic equations. J. Atmos. Sci.,32, 233–242.

  • Howarth, L., 1935: On the calculation of steady flow in the boundary layer near the surface of a cylinder in a stream. Aero. Res. Counc., Lond., R&M no. 1632.

  • Kawasaki, Y., and T. Sugimoto, 1984: Experimental studies on the formation and generation processes of the Tsugaru Warm Gyre. Ocean Hydrodynamics of the Japan and East China Seas, T. Ichiye, Ed., Oceanogr. Series, No. 39, Elsevier, 225–238.

  • Kemp, N. H., 1959: Vorticity interaction at an axisymmetric stagnation point in a viscous incompressible fluid. J. Aerosp. Sci.,26, 543–544.

  • Klinger, B. A., 1994: Inviscid current separation from rounded capes. J. Phys. Oceanogr.,24, 1805–1811.

  • La Violette, P. E., 1986: Short term measurements of surface currents associated with the Alboran Sea during ¿Donde Va? J. Phys. Oceanogr.,16, 262–279.

  • Lakshminarayana, B., and J. H. Horlock, 1973: Generalized equations for secondary vorticity using intrinsic co-ordinates. J. Fluid Mech.,59, 97–115; Corrigendum, 226, 661–663.

  • Lanoix, F., 1974: Projet Alboran, Etude hydrologique et dynamique de la Mer d’Alboran. Tech. Rep. 66, NATO, Brussels, 39 pp. plus 32 figs. [Available from NATO Subcommittee on Oceanographic Research, Copenhagen, Denmark.].

  • Li, T. Y., 1955: Simple shear flow past a flat plate in an incompressible fluid of small viscosity. J. Aeronaut. Sci.,22, 651–652.

  • ——, 1956: Effects of free-stream vorticity on the behaviour of a viscous boundary layer. J. Aeronaut. Sci.,23, 1128–1129.

  • Lynch, P., and X.-Y. Huang, 1992: Initialization of the HIRLAM model using a digital filter. Mon. Wea. Rev.,120, 1019–1034.

  • Marris, A. W., 1964: Generation of secondary vorticity in a stratified fluid. J. Fluid Mech.,20, 117–181.

  • ——, and S. L. Passman, 1968: Vector fields and flows on developable surfaces. Arch. Ration. Mech. Anal.,31, 29–86.

  • Masotti, A., 1927: Decomposizione intrinseca del vortice e sue applicazioni. Inst. Lombardo Sci. Lett. Rendiconti,60(2), 869–874.

  • Morse, P. M., and H. Feshbach, 1953: Methods of Theoretical Physics. Part I. McGraw-Hill, 997 pp.

  • Onken, R., 1990: The creation of reversed baroclinicity and subsurface jets in oceanic eddies. J. Phys. Oceanogr.,20, 786–791.

  • Ou, H. W., and W. P. M. De Ruijter, 1986: Separation of an inertial boundary current from a curved coastline. J. Phys. Oceanogr.,16, 280–289.

  • Page, M. A., 1987: Separation and free-streamlines flows in a rotating fluid at low Rossby number. J. Fluid Mech.,179, 155–177.

  • Parrilla, G., and T. H. Kinder, 1987: The physical oceanography of the Alboran Sea. Rep. Meteor. Oceanogr.,1, 143–184.

  • ——, ——, and R. H. Preller, 1986: Deep and intermediate Mediterranean water in the western Alboran Sea. Deep-Sea Res.,33, 55–88.

  • Pedlosky, J., 1987: Geophysical Fluid Dynamics. 2d ed. Springer-Verlag, 710 pp.

  • Peregrine, D. H., 1981: The fascination of fluid mechanics. J. Fluid Mech.,106, 59–80.

  • Perkins, H., T. Kinder, and P. E. La Violette, 1990: The Atlantic inflow in the western Alboran Sea. J. Phys. Oceanogr.,20, 242–263.

  • Rott, N., and M. Lenard, 1959: Vorticity effect on the stagnation-point flow of a viscous incompressible fluid. J. Aerosp. Sci.,26, 542–543.

  • Sadeh, W. Z., and H. J. Brauer, 1980: A visual investigation of turbulence in stagnation flow about a circular cylinder. J. Fluid Mech.,99, 53–64.

  • Schlichting, H., 1979: Boundary-Layer Theory. McGraw-Hill, 817 pp.

  • Schouten, J. A., 1954: Ricci-Calculus. An Introduction to Tensor Analysis and Its Geometrical Applications. 2d ed. Springer-Verlag, 516 pp.

  • Scorer, R. S., 1978: Environmental Aerodynamics. Ellis Horwood, 488 pp.

  • ——, and S. D. R. Wilson, 1963: Secondary instability in steady gravity waves. Quart. J. Roy. Meteor. Soc.,89, 532–539.

  • Shi, C., and D. Nof, 1993: The splitting of eddies along boundaries. J. Mar. Res.,51, 771–795.

  • Signell, R. P., and W. R. Geyer, 1991: Transient eddy formation around headlands. J. Geophys. Res.,96, 2561–2575.

  • Speziale, C. G., 1987: On helicity fluctuations in turbulence. Quart. Appl. Math.,45, 123–129.

  • Squire, H. B., and G. Winter, 1951: The secondary flow in a cascade of airfoils in a nonuniform stream. J. Aeronaut. Sci.,18, 271–277.

  • Stuart, J. T., 1959: The viscous flow near a stagnation point when the external flow has uniform vorticity. J. Aerosp. Sci.,26, 124–125.

  • Sutera, S. P., 1965: Vorticity amplification in stagnation-point flow and its effect on heat transfer. J. Fluid Mech.,21, 513–534.

  • ——, P. F. Maeder, and J. Kestin, 1963: On the sensitivity of heat transfer in the stagnation-point boundary layer to free-stream vorticity. J. Fluid Mech.,16, 497–520; Corregendum, 17, 480.

  • Tai, C.-T., 1992: Generalized Vector and Dyadic Analysis. IEEE Press, 134 pp.

  • Truesdell, C., 1953: Two measures of vorticity. J. Ration. Mech. Anal.,2, 173–217.

  • ——, 1954: Kinematics of Vorticity. Indiana University Press, 232 pp.

  • ——, 1991: A First Course in Rational Continuum Mechanics. Vol. 1. 2d ed. Academic Press, 391 pp.

  • ——, and R. Toupin, 1960: The classical field theories. Handbuch der Physik III/I, S. Flügge, Ed., Springer-Verlag, 902 pp.

  • Vázquez-Cuervo, J., J. Font, and J. J. Martínez-Benjamín, 1996: Observations on the circulation in the Alboran Sea using ERS1 altimetry and sea surface temperature data. J. Phys. Oceanogr.,26, 1426–1447.

  • Viúdez, A., and R. L. Haney, 1996: On the shear and curvature vorticity equations. J. Atmos. Sci.,53, 3384–3394.

  • ——, J. Tintoré, and R. L. Haney, 1996a: Circulation in the Alboran Sea as determined by quasi-synoptic hydrographic observations. Part I: Three-dimensional structure of the two anticyclonic gyres. J. Phys. Oceanogr.,26, 684–705.

  • ——, R. L. Haney, and J. Tintoré, 1996b: Circulation in the Alboran Sea as determined by quasi-synoptic hydrographic observations. Part II: Mesoscale ageostrophic motion diagnosed through density dynamical assimilation. J. Phys. Oceanogr.,26, 706–724.

  • Watson, E. J., 1964: The radial spread of a liquid jet over a horizontal plane. J. Fluid Mech.,20, 481–499.

  • Whitehead, J. A., Jr., 1985a: A laboratory study of gyres and uplift near the Strait of Gibraltar. J. Geophys. Res.,90, 7045–7060.

  • ——, 1985b: The deflection of a baroclinic jet by a wall in a rotating fluid. J. Fluid Mech.,157, 79–93.

  • ——, and A. R. Miller, 1979: Laboratory simulations of the gyre in the Alboran Sea. J. Geophys. Res.,84, 3733–3742.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 940 728 312
PDF Downloads 152 50 4