• Alvera-Azcarate, A., , A. Barth, , and R. H. Weisberg, 2009: Surface circulation of the Caribbean Sea and the Gulf of Mexico as inferred from satellite altimetry. J. Phys. Oceanogr., 39, 640657.

    • Search Google Scholar
    • Export Citation
  • Behringer, D. W., , R. L. Molinari, , and J. F. Festa, 1977: The variability of anticyclonic current patterns in the Gulf of Mexico. J. Geophys. Res., 82, 54695476.

    • Search Google Scholar
    • Export Citation
  • Chang, Y.-L., , and L.-Y. Oey, 2010: Why can wind delay the shedding of Loop Current eddies? J. Phys. Oceanogr., 40, 24812495.

  • Chang, Y.-L., , and L.-Y. Oey, 2011: Loop Current Cycle: Coupled response of Loop Current and deep flows. J. Phys. Oceanogr., 41, 458471.

    • Search Google Scholar
    • Export Citation
  • Chang, Y.-L., , and L.-Y. Oey, 2012: Why does the Loop Current tend to shed more eddies in summer and winter? Geophys. Res. Lett., 39, L05605, doi:10.1029/2011GL050773.

    • Search Google Scholar
    • Export Citation
  • Chang, Y.-L., , L.-Y. Oey, , F.-H. Xu, , H.-F. Lu, , and A. Fujisaki, 2011: 2010 Oil Spill—Trajectory projections based on ensemble drifter analyses. Ocean Dyn., 61, 829839, doi:10.1007/s10236-011-0397-4.

    • Search Google Scholar
    • Export Citation
  • Hurlburt, H. E., , and J. D. Thompson, 1980: A numerical study of Loop Current intrusions and eddy shedding. J. Phys. Oceanogr., 10, 16111651.

    • Search Google Scholar
    • Export Citation
  • Leben, R. R., 2005. Altimeter-derived Loop Current metrics. Circulation in the Gulf of Mexico: Observations and Models, Geophys. Monogr., Vol. 161, Amer. Geophys. Union, 181–201.

  • Leipper, D. F., 1970: A sequence of current patterns in the Gulf of Mexico. J. Geophys. Res., 75, 637657.

  • Lin, X., , L.-Y. Oey, , and D.-P. Wang, 2007: Altimetry and drifter assimilations of Loop Current and eddies. J. Geophys. Res., 112, C05046, doi:10.1029/2006JC003779.

    • Search Google Scholar
    • Export Citation
  • Lin, Y., , R. J. Greatbatch, , and J. Sheng, 2010: The influence of Gulf of Mexico Loop Current intrusion on the transport of the Florida Current. Ocean Dyn., 60, 10751084.

    • Search Google Scholar
    • Export Citation
  • Lugo-Fernandez, A., 2007: Is the Loop Current a chaotic oscillator? J. Phys. Oceanogr., 37, 14551469.

  • Merrifield, M. A., , and R. T. Guza, 1990: Detecting propagating signals with complex empirical orthogonal functions: A cautionary note. J. Phys. Oceanogr., 20, 16281633.

    • Search Google Scholar
    • Export Citation
  • Molinari, R. L., , J. F. Festa, , and D. Behringer, 1978: The circulation in the Gulf of Mexico derived from estimated dynamic height fields. J. Phys. Oceanogr., 8, 987996.

    • Search Google Scholar
    • Export Citation
  • Murphy, S. J., , H. E. Hurlburt, , and J. J. O’Brien, 1999: The connectivity of eddy variability in the Caribbean Sea, the Gulf of Mexico, and the Atlantic Ocean. J. Geophys. Res., 104 (C1), 14311453.

    • Search Google Scholar
    • Export Citation
  • Nof, D., 2005: The momentum imbalance paradox revisited. J. Phys. Oceanogr., 35, 19281939.

  • Oey, L.-Y., 2004: Vorticity flux in the Yucatan Channel and Loop Current Eddy shedding in the Gulf of Mexico. J. Geophys. Res., 109, C10004, doi:10.1029/2004JC002400.

    • Search Google Scholar
    • Export Citation
  • Oey, L.-Y., 2008: Loop current and deep eddies. J. Phys. Oceanogr., 38, 14261449.

  • Oey, L.-Y., , H. Lee, , and W. J. Schmitz, 2003: Effects of winds and Caribbean eddies on the frequency of Loop Current eddy shedding. J. Geophys. Res., 108, 3324, doi:10.1029/2002JC001698.

    • Search Google Scholar
    • Export Citation
  • Oey, L.-Y., , T. Ezer, , and H. J. Lee, 2005: Loop Current, rings, and related circulation in the Gulf of Mexico: A review of numerical models and future challenges. Circulation in the Gulf of Mexico: Observations and Models, Geophys. Monogr., Vol. 161, Amer. Geophys. Union, 31–56.

  • Pichevin, T., , and D. Nof, 1997: The momentum imbalance paradox. Tellus, 49, 298319.

  • Reid, R. O., 1972: A simple dynamic model of the Loop Current. Contributions on the Physical Oceanography of the Gulf of Mexico, Vol. II, L. R. A. Capurro and J. L. Reid, Eds., Gulf Publishing Co., 157–159.

  • Rio, M. H., , S. Guinehut, , and G. Larnicol, 2011: New CNES-CLS09 global mean dynamic topography computed from the combination of GRACE data, altimetry, and in situ measurements. J. Geophys. Res., 116, C07018, doi:10.1029/2010JC006505.

    • Search Google Scholar
    • Export Citation
  • Rousset, C., , and L. M. Beal, 2010: Observations of the Florida and Yucatan Currents from a Caribbean cruise ship. J. Phys. Oceanogr., 40, 15751581.

    • Search Google Scholar
    • Export Citation
  • Sturges, W., , and J. C. Evans, 1983: Variability of Loop Current in Gulf of Mexico. J. Mar. Res., 41, 639653.

  • Xu, F., , Y. Chang, , L. Oey, , and P. Hamilton, 2013: Loop Current growth and eddy shedding using models and observations: Analyses of the July 2011 eddy-shedding event. J. Phys. Oceanogr., in press.

    • Search Google Scholar
    • Export Citation
  • Yin, X.-Q., , and L.-Y. Oey, 2007: Bred-ensemble ocean forecast of Loop Current and eddies. Ocean Modell., 17, 300326.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 174 174 6
PDF Downloads 177 177 11

Loop Current Growth and Eddy Shedding Using Models and Observations: Numerical Process Experiments and Satellite Altimetry Data

View More View Less
  • 1 National Taiwan Normal University, Taipei, Taiwan, and Princeton University, Princeton, New Jersey
  • | 2 Princeton University, Princeton, New Jersey, and National Central University, Jhongli, Taiwan
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

Recent studies on Loop Current’s variability in the Gulf of Mexico suggest that the system may behave with some regularity forced by the biannually varying trade winds. The process is analyzed here using a reduced-gravity model and satellite data. The model shows that a biannual signal is produced by vorticity and transport fluctuations in the Yucatan Channel because of the piling up and retreat of warm water in the northwestern Caribbean Sea forced by the biannually varying trade wind. The Loop grows and expands with increased northward velocity and cyclonic vorticity of the Yucatan Current, and eddies are shed when these are near minima. Satellite sea surface height (SSH) data from 1993 to 2010 are analyzed. These show, consistent with the reduced-gravity experiments and previous studies, a (statistically) significant asymmetric biannual variation of the growth and wane of Loop Current: strong from summer to fall and weaker from winter to spring; the asymmetry being due to the asymmetry that also exists in the long-term observed wind. The biannual signal is contained in the two leading EOF modes, which together explain 47% of the total variance, and which additionally describe the eddy shedding and westward propagation from summer to fall. The EOFs also show connectivity between Loop Current and Caribbean Sea’s variability by mass and vorticity fluxes through the Yucatan Channel.

Corresponding author address: L.-Y. Oey, Princeton University, 70 Washington Road, Princeton, NJ 08540. E-mail: lyo@princeton.edu

Abstract

Recent studies on Loop Current’s variability in the Gulf of Mexico suggest that the system may behave with some regularity forced by the biannually varying trade winds. The process is analyzed here using a reduced-gravity model and satellite data. The model shows that a biannual signal is produced by vorticity and transport fluctuations in the Yucatan Channel because of the piling up and retreat of warm water in the northwestern Caribbean Sea forced by the biannually varying trade wind. The Loop grows and expands with increased northward velocity and cyclonic vorticity of the Yucatan Current, and eddies are shed when these are near minima. Satellite sea surface height (SSH) data from 1993 to 2010 are analyzed. These show, consistent with the reduced-gravity experiments and previous studies, a (statistically) significant asymmetric biannual variation of the growth and wane of Loop Current: strong from summer to fall and weaker from winter to spring; the asymmetry being due to the asymmetry that also exists in the long-term observed wind. The biannual signal is contained in the two leading EOF modes, which together explain 47% of the total variance, and which additionally describe the eddy shedding and westward propagation from summer to fall. The EOFs also show connectivity between Loop Current and Caribbean Sea’s variability by mass and vorticity fluxes through the Yucatan Channel.

Corresponding author address: L.-Y. Oey, Princeton University, 70 Washington Road, Princeton, NJ 08540. E-mail: lyo@princeton.edu
Save