• AVISO, 1997: AVISO user handbook: Corrected sea surface heights. Rep. AVI-NT-011-311-CN, 3.0 ed., 21 pp.

  • Ayoub, N., , Le Traon P. , , and De Mey P. , 1998: A description of the Mediterranean surface variable circulation from combined ERS-1 and TOPEX/Poseidon altimetric data. J. Mar. Syst., 18 , 340.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Basdevant, C., , and Philipovitch T. , 1994: On the validity of the “Weiss criterion” in two-dimensional turbulence. Physica D, 113 , 1730.

    • Search Google Scholar
    • Export Citation
  • Benzi, R., , Colella M. , , Paternello S. , , Santangelo P. , , and Vulpiani A. , 1986: Intermittency and coherent structures in two-dimensional turbulence. J. Phys., A19 , 37713784.

    • Search Google Scholar
    • Export Citation
  • Bouzinac, C., , Vázquez J. , , and Fout J. , 1998: CEOF analysis of ERS-1 and TOPEX/POSEIDON combined altimeter data in the region of the Algerian current. J. Geophys. Res., 103 , 80598071.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bracco, A., , La Casce J. , , Pasquero C. , , and Provenzalle A. , 2000: The velocity distribution of barotropic turbulence. Phys. Fluids, 12 , 24782488.

  • Chong, M. S., , Perry A. E. , , and Cantwell B. , 1990: A general classification of three-dimensional flow field. Phys. Fluids, A2 , 765777.

    • Search Google Scholar
    • Export Citation
  • Courant, R., , and John F. , 1989: Introduction to Calculus and Analysis. Vol. 2. Springer-Verlag., 954 pp.

  • Elhmaïdi, D., , Provenzale A. , , and Babiano A. , 1993: Elementary topology of two-dimensional turbulence from a Lagrangian viewpoint and single-particle dispersion. J. Fluid Mech., 257 , 533558.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fuda, J. L., , Millot C. , , Taupier-Letage I. , , Send U. , , and Bocognano J. M. , 2000: XBT monitoring of a meridian section across the western Mediterranean Sea. Deep-Sea Res. I, 47 , 21912218.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Goni, G., , and Johns W. , 2001: A census of North Brazil Current rings observed from TOPEX/Poseidon altimetry: 1992–1998. Geophys. Res. Lett., 28 , 14.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Holland, C., , and Mitchum G. , 2001: Propagation of Big Island eddies. J. Geophys. Res., 106 , 935944.

  • Hooker, S., , Brown J. , , and Kirwan A. , 1995: Kinematics of warm-core dipole rings. J. Geophys. Res., 100 , 2479724809.

  • Hooker, S., , Mied R. , , Brown J. , , and Kirwan A. , 1997: Remote sensing of dipole rings. IEEE Trans. Geosci. Remote Sens., 35 , 13941399.

  • Hunt, J., , Wray A. , , and Moin P. , 1988: Eddies, stream, and convergence zones in turbulent flows. Proc. CTR Summer Program, Stanford, CA, Center for Turbulence Research, 193–208.

    • Search Google Scholar
    • Export Citation
  • Iudicone, D., , Santoleri R. , , Marullo S. , , and Gerosa P. , 1998: Sea level variability and surface statistics in the Mediterranean sea from TOPEX/Poseidon data. J. Geophys. Res., 103 , 29953011.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jeong, J., , and Hussain F. , 1995: On the identification of a vortex. J. Fluid Mech., 285 , 6994.

  • Kamenkovich, V. M., , Koshlyakov M. N. , , and Monin A. S. , Eds.,. 1986: Synoptic Eddies in the Ocean. D. Reidel, 433 pp.

  • Kelly, K., , and Strub P. , 1992: Comparison of velocity estimates from advanced very high resolution radiometer in the coastal transition zone. J. Geophys. Res., 97 , 96539668.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Larnicol, G., , Le Traon P. , , Ayoub N. , , and De Mey P. , 1995: Mean sea level and surface circulation variability of the Mediterranean Sea from 2 years of TOPEX/POSEIDON altimetry. J. Geophys. Res., 100 , 385396.

    • Search Google Scholar
    • Export Citation
  • Larnicol, G., , Ayoub N. , , and Le Traon P. , 2002: Major changes in the Mediterranean sea level variability from 7 years of TOPEX/Poseidon and ERS-1/2 data. J. Mar. Syst., 33-34 , 6389.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Le Traon, P., , and Ogor F. , 1998: ERS-1/2 orbit improvement using TOPEX/POSEIDON: The 2 cm challenge. J. Geophys. Res., 103 , 80458057.

  • Le Traon, P., , Nadal F. , , and Ducet N. , 1998: An improved mapping method of multisatellite altimeter data. J. Atmos. Oceanic Technol., 15 , 522534.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McWilliams, J., 1984: The emergence of isolated coherent vortices in turbulent flow. J. Fluid Mech., 146 , 2143.

  • Millot, C., 1991: Mesoscale and seasonal variabilities of the circulation in the western Mediterranean. Dyn. Atmos. Oceans, 15 , 179214.

  • Nihoul, J. C. J., , and Jamart B. , Eds.,. 1989: Mesoscale/Synoptic Coherent Structures in Geophysical Turbulence. Elsevier Oceanography Series, Vol. 50, Elsevier, 841 pp.

    • Search Google Scholar
    • Export Citation
  • Obaton, D., , Millot C. , , D’Hières G. Chabert , , and Taupier-Letage I. , 2000: The Algerian current: Comparisons between in situ and laboratory data sets. Deep-sea Res., 47 , 21592190.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Okubo, A., 1970: Horizontal dispersion of floatable particles in the vicinity of velocity singularities such as convergences. Deep-Sea Res., 17 , 445454.

    • Search Google Scholar
    • Export Citation
  • Pasquero, C., , Provenzale A. , , and Babiano A. , 2001: Parametrization of dispersion in two-dimensional turbulence. J. Fluid Mech., 439 , 279303.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Puillat, I., , Taupier-Letage I. , , and Millot C. , 2002: Algerian eddies lifetime can near 3 years. J. Mar. Syst., 31 , 245259.

  • Robinson, A., 1983: Eddies in Marine Science. Springer Verlag, 609 pp.

  • Salas, J., , García-Ladona E. , , and Font J. , 2002a: Statistical analysis of the surface circulation in the Algerian current using Lagrangian buoys. J. Mar. Syst., 29 , 6985.

    • Search Google Scholar
    • Export Citation
  • Salas, J., , Millot C. , , Font J. , , and García-Ladona E. , 2002b: Analysis of mesoscale phenomena in the Algerian basin from drifting buoys and infrared images. Deep-Sea Res., 49 , 245266.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Stammer, D., 1997: Global characteristics of ocean variability estimated from regional TOPEX/Poseidon altimeter measurements. J. Phys. Oceanogr., 27 , 17431769.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vignudelli, S., 1997: Potential use of ERS-1 and Topex/Posseidon altimeters for resolving oceanographic patterns in the Algerian Basin. Geophys. Res. Lett., 24 , 17871790.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Weiss, J., 1991: The dynamics of enstrophy transfer in two-dimensional hydrodynamics. Physica D, 48 , 273294.

  • Wilkin, J. L., , and Morrow R. A. , 1994: Eddy kinetic energy and momentum flux in the Southern Ocean: Comparisons of a global eddy-resolving model with altimeter, drifter and current-meter data. J. Geophys. Res., 99 , 79037916.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 252 252 16
PDF Downloads 118 118 18

Identification of Marine Eddies from Altimetric Maps

View More View Less
  • 1 Institut de Ciències del Mar (CSIC), Barcelona, Spain
© Get Permissions
Restricted access

Abstract

A procedure is presented to detect eddy cores from sea level anomaly (SLA) maps obtained from altimetric measurements. The method is based on finding the sign of Q, which is an invariant of the velocity gradient tensor (∇u). This parameter, commonly used in studies of two-dimensional turbulence, measures the relative contribution of deformation and vorticity. Vortex cores are associated with regions with large and positive values of Q. It is shown that this parameter is adequate to detect marine eddies in altimetric maps and, when the geometry of streamline contours in SLA maps is unclear, the Q > 0 criterion appears to work more consistently. The performance of the methodology is applied, as an example, to altimetric maps of the Algerian Basin in the Western Mediterranean Sea, where two long-lived eddies are tracked. The observed trajectories are in good agreement with Advanced Very High Resolution Radiometer (AVHRR) images.

Corresponding author address: Jordi Isern-Fontanet, Physical Oceanography Group, Institut de Ciències del Mar, CMIMA (CSIC), Passeig Marítim de la Barceloneta, 37–49, E-08003 Barcelona, Spain. Email: jisern@cmima.csic.es

Abstract

A procedure is presented to detect eddy cores from sea level anomaly (SLA) maps obtained from altimetric measurements. The method is based on finding the sign of Q, which is an invariant of the velocity gradient tensor (∇u). This parameter, commonly used in studies of two-dimensional turbulence, measures the relative contribution of deformation and vorticity. Vortex cores are associated with regions with large and positive values of Q. It is shown that this parameter is adequate to detect marine eddies in altimetric maps and, when the geometry of streamline contours in SLA maps is unclear, the Q > 0 criterion appears to work more consistently. The performance of the methodology is applied, as an example, to altimetric maps of the Algerian Basin in the Western Mediterranean Sea, where two long-lived eddies are tracked. The observed trajectories are in good agreement with Advanced Very High Resolution Radiometer (AVHRR) images.

Corresponding author address: Jordi Isern-Fontanet, Physical Oceanography Group, Institut de Ciències del Mar, CMIMA (CSIC), Passeig Marítim de la Barceloneta, 37–49, E-08003 Barcelona, Spain. Email: jisern@cmima.csic.es

Save