• Barnier, B., L. Siefridt, and P. Marchesiello, 1995: Thermal forcing for a global ocean circulation model using a three-year climatology of ECMWF analysis. J. Mar. Syst.,6, 363–380.

  • Beckmann, A., 1988: Vertical structure of midlatitude mesoscale instabilities. J. Phys. Oceanogr.,18, 1354–1371.

  • ——, C. W. Böning, C. Köberle, and J. Willebrand, 1994: Effects of increased horizontal resolution in a simulation of the North Atlantic Ocean. J. Phys. Oceanogr.,24, 326–344.

  • Böning, C., and R. G. Budich, 1992: Eddy dynamics in a primitive equation model: Sensitivity to horizontal resolution and friction. J. Phys. Oceanogr.,22, 361–381.

  • Bryden, H. L., 1983: The Southern Ocean. Eddies in Marine Science, A. R. Robinson, Ed., Springer, 265–277.

  • Cunningham, S. A., S. G. Alderson, and B. A. King, 1995: Inter-annual variations in the mass flux of the Antarctic Circumpolar Current at Drake Passage on WOCE repeat hydrography section, SR1. Abstracts, 221st General Assembly of the Int. Assoc. for the Physical Sciences of the Oceans (IAPSO), Honolulu, HI, 25.

  • Dukowicz, J. K., and R. D. Smith, 1994: Implicit free-surface method for the Bryan–Cox–Semtner ocean model. J. Geophys. Res.,99, 7991–8014.

  • ——, ——, and R. C. Malone, 1993: A reformulation and implementation of the Bryan–Cox–Semtner ocean model on the Connection Machine. J. Atmos. Oceanic Technol.,10, 196–208.

  • The FRAM Group, 1991: Initial results from a fine resolution model of the Southern Ocean. Eos, Trans. Amer. Geophys. Union,72, 174–175.

  • Gille, S. T., 1995: Dynamics of the Antarctic Circumpolar Current: Evidence for topographic effects from altimeter data and numerical model output. Ph.D. thesis, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 217 pp.

  • Gouretski, V. V., A. I. Danilov, V. O. Ivchenko, and A. V. Klepikov, 1987: Modelling of the Southern Ocean Circulation. Hydrometeorologisher, Leningrad, 200 pp.

  • Grose, T. J., J. A. Johnson, and G. R. Bigg, 1995: A comparison between the FRAM (Fine Resolution Antarctic Model) results and observations in the Drake Passage. Deep-Sea Res.,42, 365–388.

  • Hellerman, S., and M. Rosenstein, 1983: Normal monthly wind stress over the World Ocean with error estimates. J. Phys. Oceanogr.,13, 1093–1104.

  • Holland, W. R., 1975: Energetics of baroclinic oceans. Numerical Models of Ocean Circulation, National Academy Press, 168–177.

  • Ivchenko, V. O., K. J. Richards, and D. P. Stevens, 1996: The dynamics of the Antarctic Circumpolar Current. J. Phys. Oceanogr.,26, 753–774.

  • ——, A. M. Treguier, and S. E. Best, 1997: A kinetic energy budget and internal instabilities in the Fine Resolution Antarctic Model. J. Phys. Oceanogr.,27, 5–22.

  • Johnson, G. C., and H. L. Bryden, 1989: On the size of the Antarctic Circumpolar Current. Deep-Sea Res.,36, 39–53.

  • Killworth, P. K., and M. M. Nanneh, 1994: On the isopycnal momentum budget of the Antarctic Circumpolar Current in the Fine Resolution Antarctic Model. J. Phys. Oceanogr.,24, 1201–1223.

  • Le Traon, P. Y., J. Stum, J. Dorandeu, and P. Gaspar, 1994: Global statistical analysis of TOPEX and POSEIDON data. J. Geophys. Res.,99 (C12), 24 619–24 631.

  • Levitus, S., 1982: Climatological Atlas of the World Ocean. NOAA Prof. Paper No. 13, U.S. Govt. Printing office, 173 pp.

  • Marshall, J., D. Olbers, H. Ross, and D. Wolf-Gladrow, 1993: Potential vorticity constraints on the dynamics and hydrography of the Southern Ocean. J. Phys. Oceanogr.,23, 465–487.

  • McWilliams, J. C., W. R. Holland, and J. S. Chow, 1978: A description of numerical Antarctic Circumpolar Currents. Dyn. Atmos. Oceans.,2, 213–291.

  • Munk, W. H., and E. Palmén, 1951: Note on the dynamics of the Antarctic Circumpolar Current. Tellus,3, 53–55.

  • Nowlin, W. D., Jr, and J. M. Klinck, 1986: The physics of the Antarctic Circumpolar Current. Rev. Geophys.,24, 469–491.

  • Pacanowski, R. C., and S. G. H. Philander, 1981: Parameterization of vertical mixing in numerical models of tropical oceans. J. Phys. Oceanogr.,11, 1443–1451.

  • Park, Y. H., L. Gamberoni, and E. Charriand, 1993: Frontal structure, water masses and circulation in the Crozet Basin. J. Geophys. Res.,98, 12 361–12 385.

  • Quartly, G. D., and M. A. Srokosz, 1993: Seasonal variations in the region of the Agulhas Retroflection: Studies with GEOSAT and FRAM. J. Phys. Oceanogr.,23, 2107–2124.

  • Sarukhanian, E. I., and N. P. Smirnoff, 1986: Water Masses and Circulation of the Southern Ocean. Hydrometeorologisher Publ., Leningrad, 288 pp.

  • Semtner, A. J., and R. M. Chervin, 1988: A simulation of the Global Ocean circulation with resolved eddies. J. Geophys. Res.,93, 15 502–15 522.

  • ——, and ——, 1992: Ocean general circulation from a global eddy-resolving model. J. Geophys. Res.,97, 5493–5550.

  • Smith, R. D., J. K. Dukowicz, and R. C. Malone, 1992: Parallel ocean general circulation modeling. Physica D,60, 38–61.

  • Stevens, D. P., 1990: On open boundary conditions for three-dimensional primitive equation ocean circulation models. Geophys. Astrophys. Fluid Dyn.,51 (1–4), 103–133.

  • ——, and P. D. Killworth, 1992: The distribution of kinetic energy in the Southern Ocean: A comparison between observations and an eddy resolving general circulation model. Philos. Trans. Roy. Soc. London,338B, 251–257.

  • ——, and V. O. Ivchenko, 1997: The zonal momentum balance in an eddy-resolving general-circulation model of the Southern Ocean. Quart. J. Roy. Meteor. Soc.,123, 929–951.

  • Toggweiler, J. R., and B. Samuels, 1995: Effect of Drake Passage on the global thermohaline circulation. Deep-Sea Res.,42, 477–500.

  • Treguier, A. M., 1992: Kinetic energy analysis of an eddy resolving, primitive equation model of the North Atlantic. J. Geophys. Res.,97, 687–701.

  • ——, and J. C. McWilliams, 1990: Topographic influences on wind-driven, stratified flow in a β-plane channel: An idealized model for the Antarctic Circumpolar Current. J. Phys. Oceanogr.,20, 321–343.

  • Webb, D. J., P. D. Killworth, A. C. Coward, and S. R. Thompson, 1991: The FRAM Atlas of the Southern Ocean. Natural Environment Research Council, 67 pp.

  • Wilkin, J. L., and R. A. Morrow, 1994: Eddy kinetic energy and momentum flux in the Southern Ocean: Comparison of a global eddy-resolving model with altimeter, drifter, and current-meter data. J. Geophys. Res.,99, 7903–7916.

  • Wolff, J.-O., E. Maier-Reimer, and D. J. Olbers, 1991: Wind-driven flow over topography in a zonal β-plane channel: A quasigeostrophic model of the Antarctic Circumpolar Current. J. Phys. Oceanogr.,21, 236–264.

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Eddies in Numerical Models of the Antarctic Circumpolar Current and Their Influence on the Mean Flow

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  • 1 Department of Oceanography, Southampton Oceanography Centre, University of Southampton, Southampton, United Kingdom
  • | 2 Los Alamos National Laboratory, Los Alamos, New Mexico
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Abstract

The dynamics of the Southern Ocean have been studied using two high-resolution models, namely the Fine Resolution Antarctic Model (FRAM) and the Parallel Ocean Program (POP) model. Analysis of these models includes zonal averaging at Drake Passage latitudes, averaging along streamlines (or contours of constant sea surface height), and examining particular subregions of the flow in some detail. The subregions considered in the local analysis capture different flow regimes in the vicinity of the Crozet Plateau, the Macquarie–Ridge Complex, and Drake Passage.

Many aspects of the model results are similar, for example, the magnitude of eddy kinetic energy (EKE) in the “eddy rich” regions associated with the large-scale topography. An important difference between the two models is that away from the strong topographic features the level of EKE in POP is 2–4 times greater than in FRAM, giving values close to those observed in altimeter studies.

In both FRAM and POP instability analysis performed over ACC jets showed that baroclinic instability is likely to be the main mechanism responsible for generating EKE. In the case of FRAM this view is confirmed by regional energy budgets made within the ACC. In contrast to quasigeostrophic numerical experiments upgradient transfer of momentum was not found in the whole ACC, or over large subregions of the Southern Ocean. The only place it occurred was in localized tight jets (e.g., the flow northeast of Drake Passage) where the transients are found to transfer kinetic energy into energy of the mean flow. The transient eddies result in a net deceleration of the ACC for the streamwise averaging.

Corresponding author address: Dr. Vladimir O. Ivchenko, Department of Oceanography, The University of Southampton, Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, United Kingdom.

Abstract

The dynamics of the Southern Ocean have been studied using two high-resolution models, namely the Fine Resolution Antarctic Model (FRAM) and the Parallel Ocean Program (POP) model. Analysis of these models includes zonal averaging at Drake Passage latitudes, averaging along streamlines (or contours of constant sea surface height), and examining particular subregions of the flow in some detail. The subregions considered in the local analysis capture different flow regimes in the vicinity of the Crozet Plateau, the Macquarie–Ridge Complex, and Drake Passage.

Many aspects of the model results are similar, for example, the magnitude of eddy kinetic energy (EKE) in the “eddy rich” regions associated with the large-scale topography. An important difference between the two models is that away from the strong topographic features the level of EKE in POP is 2–4 times greater than in FRAM, giving values close to those observed in altimeter studies.

In both FRAM and POP instability analysis performed over ACC jets showed that baroclinic instability is likely to be the main mechanism responsible for generating EKE. In the case of FRAM this view is confirmed by regional energy budgets made within the ACC. In contrast to quasigeostrophic numerical experiments upgradient transfer of momentum was not found in the whole ACC, or over large subregions of the Southern Ocean. The only place it occurred was in localized tight jets (e.g., the flow northeast of Drake Passage) where the transients are found to transfer kinetic energy into energy of the mean flow. The transient eddies result in a net deceleration of the ACC for the streamwise averaging.

Corresponding author address: Dr. Vladimir O. Ivchenko, Department of Oceanography, The University of Southampton, Southampton Oceanography Centre, European Way, Southampton SO14 3ZH, United Kingdom.

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