Editorial Type:
Article
Article Type:
Research Article

Application of the GWR Method to the Tropical Indian Ocean

Tommy G. Jensen International Pacific Research Center, University of Hawaii at Manoa, Honolulu, Hawaii

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Print Publication:
01 Mar 2001
DOI:
https://doi.org/10.1175/1520-0493(2001)129<0470:AOTGMT>2.0.CO;2
Page(s):
470–485
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Abstract

The gravity wave retardation (GWR) method is a simple technique that allows layer models to include bottom topography. Here the method is applied, and its accuracy is evaluated, for monthly climatological wind forcing in an Indian Ocean model with realistic bottom topography. This is an extension of previous studies where the GWR method was applied to idealized wind forcing in oceans with idealized basin geometry. Comparison to a model integration with a flat bottom demonstrates that GWR integrations with speedup factors of up to 16 indeed capture the influence of the bottom relief and have less error in the deep volume transports. For a speedup factor of that magnitude, a GWR integration is also found to have less error than a reduced gravity model simulation. It is concluded that integrations using the GWR method give remarkably good results for the upper-layer circulation as well as the deep flow with a speedup factor of up to 8.

Corresponding author address: Dr. Tommy G. Jensen, IPRC/SOEST, University of Hawaii, 2525 Correa Road, Honolulu, HI 97822.

Abstract

The gravity wave retardation (GWR) method is a simple technique that allows layer models to include bottom topography. Here the method is applied, and its accuracy is evaluated, for monthly climatological wind forcing in an Indian Ocean model with realistic bottom topography. This is an extension of previous studies where the GWR method was applied to idealized wind forcing in oceans with idealized basin geometry. Comparison to a model integration with a flat bottom demonstrates that GWR integrations with speedup factors of up to 16 indeed capture the influence of the bottom relief and have less error in the deep volume transports. For a speedup factor of that magnitude, a GWR integration is also found to have less error than a reduced gravity model simulation. It is concluded that integrations using the GWR method give remarkably good results for the upper-layer circulation as well as the deep flow with a speedup factor of up to 8.

Corresponding author address: Dr. Tommy G. Jensen, IPRC/SOEST, University of Hawaii, 2525 Correa Road, Honolulu, HI 97822.

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  • Abbott, M. B., A. McCowan, and I. R. Warren, 1981: Numerical modelling of free-surface flows that are two-dimensional in plan. Transport Models for Inland and Coastal Waters: Proceedings of a Symposium on Predictive Ability, H. B. Fischer, Ed., Academic Press, 222–283.

  • Benson, D. J., 1992: Computational methods in Lagrangian and Eulerian hydrocodes. Comp. Methods Appl. Mech. Eng.,99, 235–394.

  • Bleck, R., and L. Smith, 1990: A wind-driven isopycnic coordinate model of the North and equatorial Atlantic Ocean. Part I: Model development and supporting experiments. J. Geophys. Res.,95, 3273–3286.

  • Blumberg, A. F., and G. L. Mellor, 1987: A description of a three-dimensional coastal ocean circulation model. Three-Dimensional Coastal Ocean Models, N. Heaps, Ed., Amer. Geophys. Union, 1–16.

  • Bryan, K., 1969: A numerical method for the study of the circulation of the world ocean. J. Comput. Phys.,4, 347–376.

  • ——, 1984: Accelerating the convergence to equilibrium of ocean–climate models. J. Phys. Oceanogr.,14, 666–673.

  • Busalacchi, A. J., and J. J. O’Brien, 1980: The seasonal variability in a model of the tropical Pacific. J. Phys. Oceanogr.,10, 1929–1951.

  • Charney, J. G., and G. R. Flierl, 1981: Oceanic analogues of large-scale atmospheric motions. Evolution of Physical Oceanography, B. A. Warren and C. Wunsch, Eds., MIT Press, 504–548.

  • Chorin, A. J., 1967: A numerical method for solving incompressible viscous flow problems. J. Comput. Phys.,2, 12–26.

  • Hallberg, R., 1997: Stable split time stepping schemes for large scale ocean modelling. J. Comput. Phys.,135, 54–65.

  • Hearn, C. J., and J. R. Hunter, 1987: Modelling wind-driven flow in shallow water systems on the southwest Australian coast. Numerical Modelling: Applications to Marine Systems, J. Noye, Ed., Elsevier 47–57.

  • Higdon, R. L., 1999: Implementation of a barotropic–baroclinic time splitting for isopycnic coordinate ocean modeling. J. Comput. Phys.,148, 579–604.

  • ——, and A. F. Bennett, 1996: Stability analysis of operator splitting for large-scale ocean modeling. J. Comput. Phys.,123, 311–329.

  • ——, and R. A. de Szoeke, 1997: Barotropic–baroclinic time splitting for ocean circulation modeling. J. Comput. Phys.,135, 30–53.

  • Hunter, J. R., 1990a: User manual for numerical hydrodynamic models of marine systems and associated plotting package. CSIRO Division of Oceanography Rep. OMR-14/00, 73 pp. [Available from CSIRO Division of Oceanography, Hobart, Tasmania 7001, Australia.].

  • ——, 1990b: User manual for three-dimensional numerical hydrodynamic and dispersion model. CSIRO Division of Oceanography Rep. OMR-24/00, 44 pp. [Available from CSIRO Division of Oceanography, Hobart, Tasmania 7001, Australia.].

  • Jensen, T. G., 1991: Modeling the seasonal undercurrents in the Somali Current system. J. Geophys. Res.,96, 22 151–22 167.

  • ——, 1993: Equatorial variability and resonance in a wind-driven Indian Ocean model. J. Geophys. Res.,98, 22 533–22 552.

  • ——, 1996: Artificial retardation of barotropic waves in layered ocean models. Mon. Wea. Rev.,124, 1272–1283.

  • ——, 1998: Description of a Thermodynamic Ocean Modelling System (TOMS). Dept. of Atmospheric Science Paper No. 670, Colorado State University, 50 pp. [Available from Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371.].

  • Killworth, P. D., D. Stainforth, D. J. Webb, and S. M. Paterson, 1991:The development of a free-surface Bryan–Cox–Semtner ocean model. J. Phys. Oceanogr.,21, 1333–1348.

  • Knox, R. A., and D. L. T. Anderson, 1985: Recent advances in the study of the low-latitude ocean circulation. Progress in Oceanography, Vol. 14, Pergamon Press, 259–317.

  • Luyten, J. R., and D. H. Roemmich, 1982: Equatorial currents at semi-annual period in the Indian Ocean. J. Phys. Oceanogr.,12, 406–413.

  • Madala, R. V., and S. A. Piacsek, 1977: A semi-implicit numerical model for baroclinic oceans. J. Comput. Phys.,23, 167–178.

  • McCreary, J. P., and P. K. Kundu, 1988: A numerical investigation of the Somali Current during the southwest monsoon. J. Mar. Res.,46, 25–58.

  • ——, and ——, 1989: A numerical investigation of sea surface temperature variability in the Arabian Sea. J. Geophys. Res.,94, 16 097–16 114.

  • National Oceanic and Atmospheric Administration, 1988: ETOPO5 digital relief of the surface of the Earth. Data Announcement 86-MGG-02, National Geophysical Data Center, Boulder, Colorado. [Available from NOAA, National Geophysical Data Center, Boulder, CO 80303-3328.].

  • Oberhuber, J. M., 1993: Simulation of the Atlantic circulation with a coupled sea ice–mixed layer–isopycnal general circulation model. Part I: Model description. J. Phys. Oceanogr.,23, 808–829.

  • Potemra, J. T., M. E. Luther, and J. J. O’Brien, 1991: The seasonal circulation of the upper ocean in the Bay of Bengal. J. Geophys. Res.,96, 12 667–12 683.

  • Rao, R. R., R. L. Molinari, and J. F. Festa, 1989: Evolution of the climatological near-surface thermal structure of the tropical Indian Ocean. 1. Description of mean monthly mixed layer depth, and sea surface temperature, surface current, and surface meteorological fields. J. Geophys. Res.,94, 10 801–10 815.

  • Schott, F., 1983: Monsoon response of the Somali Current and associated upwelling. Progress in Oceanography, Vol. 12, Pergamon Press, 357–381.

  • Semtner, A. J., 1986: Finite-difference formulation of a world ocean model. Advanced Physical Oceanographic Numerical Modelling, J. J. O’Brien, Ed., Reidel, 187–202.

  • Simons, T. J., 1974: Verification of numerical models of Lake Ontario. Part I. Circulation in spring and early summer. J. Phys. Oceanogr.,4, 507–523.

  • Tobis, M., 1996: Effects of slowed barotropic dynamics in parallel ocean climate models. Ph.D. dissertation, University of Wisconsin—Madison, 198 pp. [Available from Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, Madison, WI 53706.].

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