• Amante, C., , and B. W. Eakins, 2009: ETOPO1 1 arc-minute global relief model: Procedures, data sources and analysis. NOAA Tech. Memo. NESDIS NGDC-24, 19 pp.

  • Batchelor, G. K., 1970: The Theory of Homogeneous Turbulence. Cambridge University Press, 197 pp.

  • Bretherton, F. P., , R. E. Davis, , and C. B. Fandry, 1976: A technique for objective analysis and design of oceanographic experiments applied to MODE-73. Deep-Sea Res., 23, 559582, doi:10.1016/0011-7471(76)90001-2.

    • Search Google Scholar
    • Export Citation
  • Chelton, D. B., , R. A. DeSzoeke, , M. G. Schlax, , K. E. Naggar, , and N. Siwertz, 1998: Geographical variability of the first baroclinic Rossby radius of deformation. J. Phys. Oceanogr., 28, 433460, doi:10.1175/1520-0485(1998)028<0433:GVOTFB>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Davis, R. E., 1985: Objective mapping by least-squares fitting. J. Geophys. Res., 90 (C3), 47734777, doi:10.1029/JC090iC03p04773.

  • Davis, R. E., 1998: Preliminary results from directly measuring middepth circulation in the tropical and South Pacific. J. Geophys. Res., 103 (C11), 24 61924 639, doi:10.1029/98JC01913.

    • Search Google Scholar
    • Export Citation
  • Davis, R. E., 2005: Intermediate-depth circulation of the Indian and South Pacific Oceans measured by autonomous floats. J. Phys. Oceanogr., 35, 683707, doi:10.1175/JPO2702.1.

    • Search Google Scholar
    • Export Citation
  • Fritsch, F. N., , and R. E. Carlson, 1980: Monotone piecewise cubic interpolation. SIAM J. Numer. Anal., 17, 238246, doi:10.1137/0717021.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., 2003: Large-scale mass transports, water mass formation, and diffusivities estimated from World Ocean Circulation Experiment (WOCE) hydrographic data. J. Geophys. Res., 108, 3213, doi:10.1029/2002JC001565.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., , and C. Wunsch, 2000: Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature, 408, 453457, doi:10.1038/35044048.

    • Search Google Scholar
    • Export Citation
  • Gille, S. T., 2003: Float observations of the Southern Ocean. Part I: Estimating mean fields, bottom velocities, and topographic steering. J. Phys. Oceanogr., 33, 11671181, doi:10.1175/1520-0485(2003)033<1167:FOOTSO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Hautala, S. L., , D. H. Roemmich, , and W. J. Schmitz, 1994: Is the North Pacific in Sverdrup balance along 24°N? J. Geophys. Res., 99 (C8), 16 04116 052, doi:10.1029/94JC01084.

    • Search Google Scholar
    • Export Citation
  • Holte, J., , and L. Talley, 2009: A new algorithm for finding mixed layer depths with applications to Argo data and Subantarctic Mode Water formation. J. Atmos. Oceanic Technol., 26, 19201939, doi:10.1175/2009JTECHO543.1.

    • Search Google Scholar
    • Export Citation
  • Katsumata, K., , and H. Yoshinari, 2010: Uncertainties in global mapping of Argo drift data at the parking level. J. Oceanogr., 66, 553569, doi:10.1007/s10872-010-0046-4.

    • Search Google Scholar
    • Export Citation
  • Leetmaa, A., , P. Niiler, , and H. Stommel, 1977: Does the Sverdrup relation account for the mid-Atlantic circulation? J. Mar. Res., 35, 110.

    • Search Google Scholar
    • Export Citation
  • LeTraon, P. Y., 1990: A method for optimal analysis of fields with spatially-variable mean. J. Geophys. Res., 95 (C8), 13 54313 547, doi:10.1029/JC095iC08p13543.

    • Search Google Scholar
    • Export Citation
  • Lozier, M. S., , M. S. McCartney, , and W. B. Owens, 1994: Anomalous anomalies in averaged hydrographic data. J. Phys. Oceanogr., 24, 26242638, doi:10.1175/1520-0485(1994)024<2624:AAIAHD>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Luyten, J. R., , J. Pedlosky, , and H. Stommel, 1983: The ventilated thermocline. J. Phys. Oceanogr., 13, 292309, doi:10.1175/1520-0485(1983)013<0292:TVT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Macdonald, A. M., 1998: The global ocean circulation: A hydrographic estimate and regional analysis. Prog. Oceanogr., 41, 281382, doi:10.1016/S0079-6611(98)00020-2.

    • Search Google Scholar
    • Export Citation
  • Macdonald, A. M., , and C. Wunsch, 1996: An estimate of global ocean circulation and heat fluxes. Nature, 382, 436439, doi:10.1038/382436a0.

    • Search Google Scholar
    • Export Citation
  • Niiler, P. P., , and C. J. Koblinksy, 1985: A local time-dependent Sverdrup balance in the eastern North Pacific Ocean. Science, 229, 754756, doi:10.1126/science.229.4715.754.

    • Search Google Scholar
    • Export Citation
  • Park, J. J., , K. Kim, , B. A. King, , and S. C. Riser, 2005: An advanced method to estimate deep currents from profiling floats. J. Atmos. Oceanic Technol., 22, 1294–1304, doi:10.1175/JTECH1748.1.

    • Search Google Scholar
    • Export Citation
  • Qiu, B., , and T. M. Joyce, 1992: Interannual variability in the midlatitude and low-latitude western North Pacific. J. Phys. Oceanogr., 22, 10621079, doi:10.1175/1520-0485(1992)022<1062:IVITMA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., 1989: On the total geostrophic circulation of the South Atlantic Ocean: Flow patterns, tracers, and transports. Prog. Oceanogr., 23, 149244, doi:10.1016/0079-6611(89)90001-3.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., 1994: On the total geostrophic circulation of the North Atlantic Ocean: Flow patterns, tracers, and transports. Prog. Oceanogr., 33, 192, doi:10.1016/0079-6611(94)90014-0.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., 1997: On the total geostrophic circulation of the Pacific Ocean: Flow patterns, tracers, and transports. Prog. Oceanogr., 39, 263352, doi:10.1016/S0079-6611(97)00012-8.

    • Search Google Scholar
    • Export Citation
  • Reid, J. L., 2003: On the total geostrophic circulation of the Indian Ocean: Flow patterns, tracers, and transports. Prog. Oceanogr., 56, 137186, doi:10.1016/S0079-6611(02)00141-6.

    • Search Google Scholar
    • Export Citation
  • Rhines, P. B., , and W. R. Young, 1982: A theory of the wind-driven circulation. I. Mid-ocean gyres. J. Mar. Res.,40, 559–596.

  • Ridgway, K. R., , and J. R. Dunn, 2007: Observational evidence for a Southern Hemisphere oceanic supergyre. Geophys. Res. Lett., 34, L13612, doi:10.1029/2007GL030392.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., , S. Riser, , R. Davis, , and Y. Desaubies, 2004: Autonomous profiling floats: Workhorse for broad-scale ocean observations. Mar. Technol. Soc. J., 38 (2), 2129, doi:10.4031/002533204787522802.

    • Search Google Scholar
    • Export Citation
  • Schmitz, W. J., , J. D. Thompson, , and J. R. Luyten, 1992: The Sverdrup circulation for the Atlantic along 24°N. J. Geophys. Res., 97 (C5), 72517256, doi:10.1029/92JC00417.

    • Search Google Scholar
    • Export Citation
  • Sverdrup, H., 1947: Wind-driven currents in a baroclinic ocean; with application to the equatorial currents of the eastern Pacific. Proc. Natl. Acad. Sci. USA, 33 (11), 318326, doi:10.1073/pnas.33.11.318.

    • Search Google Scholar
    • Export Citation
  • Talley, L. D., 1988: Potential vorticity distribution in the North Pacific. J. Phys. Oceanogr., 18, 89106, doi:10.1175/1520-0485(1988)018<0089:PVDITN>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Talley, L. D., , G. L. Pickard, , W. J. Emery, , and J. H. Swift, 2011: Descriptive Physical Oceanography: An Introduction. 6th ed. Academic Press, 560 pp.

    • Search Google Scholar
    • Export Citation
  • Vivier, F., , K. A. Kelly, , and L. Thompson, 1999: Contributions of wind forcing, waves, and surface heating to sea surface height observations in the Pacific Ocean. J. Geophys. Res., 104 (C9), 20 76720 788, doi:10.1029/1999JC900096.

    • Search Google Scholar
    • Export Citation
  • Wunsch, C., 2010: Toward a midlatitude ocean frequency–wavenumber spectral density and trend determination. J. Phys. Oceanogr., 40, 22642281, doi:10.1175/2010JPO4376.1.

    • Search Google Scholar
    • Export Citation
  • Wunsch, C., 2011: The decadal mean ocean circulation and Sverdrup balance. J. Mar. Res., 69, 417434, doi:10.1357/002224011798765303.

  • Wunsch, C., , and D. Roemmich, 1985: Is the North Atlantic in Sverdrup balance? J. Phys. Oceanogr., 15, 18761880, doi:10.1175/1520-0485(1985)015<1876:ITNAIS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 376 376 41
PDF Downloads 306 306 36

A Global Analysis of Sverdrup Balance Using Absolute Geostrophic Velocities from Argo

View More View Less
  • 1 School of Oceanography, University of Washington, Seattle, Washington
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

Using observations from the Argo array of profiling floats, the large-scale circulation of the upper 2000 decibars (db) of the global ocean is computed for the period from December 2004 to November 2010. The geostrophic velocity relative to a reference level of 900 db is estimated from temperature and salinity profiles, and the absolute geostrophic velocity at the reference level is estimated from the trajectory data provided by the floats. Combining the two gives the absolute geostrophic velocity on 29 pressure surfaces spanning the upper 2000 db of the global ocean. These velocities, together with satellite observations of wind stress, are then used to evaluate Sverdrup balance, the simple canonical theory relating meridional geostrophic transport to wind forcing. Observed transports agree well with predictions based on the wind field over large areas, primarily in the tropics and subtropics. Elsewhere, especially at higher latitudes and in boundary regions, Sverdrup balance does not accurately describe meridional geostrophic transports, possibly due to the increased importance of the barotropic flow, nonlinear dynamics, and topographic influence. Thus, while it provides an effective framework for understanding the zero-order wind-driven circulation in much of the global ocean, Sverdrup balance should not be regarded as axiomatic.

Corresponding author address: Alison R. Gray, School of Oceanography, University of Washington, Box 355351, Seattle, WA 98195. E-mail: alison@ocean.washington.edu

A comment/reply has been published regarding this article and can be found at http://journals.ametsoc.org/doi/abs/10.1175/JPO-D-14-0127.1 and http://journals.ametsoc.org/doi/abs/10.1175/JPO-D-14-0215.1

Abstract

Using observations from the Argo array of profiling floats, the large-scale circulation of the upper 2000 decibars (db) of the global ocean is computed for the period from December 2004 to November 2010. The geostrophic velocity relative to a reference level of 900 db is estimated from temperature and salinity profiles, and the absolute geostrophic velocity at the reference level is estimated from the trajectory data provided by the floats. Combining the two gives the absolute geostrophic velocity on 29 pressure surfaces spanning the upper 2000 db of the global ocean. These velocities, together with satellite observations of wind stress, are then used to evaluate Sverdrup balance, the simple canonical theory relating meridional geostrophic transport to wind forcing. Observed transports agree well with predictions based on the wind field over large areas, primarily in the tropics and subtropics. Elsewhere, especially at higher latitudes and in boundary regions, Sverdrup balance does not accurately describe meridional geostrophic transports, possibly due to the increased importance of the barotropic flow, nonlinear dynamics, and topographic influence. Thus, while it provides an effective framework for understanding the zero-order wind-driven circulation in much of the global ocean, Sverdrup balance should not be regarded as axiomatic.

Corresponding author address: Alison R. Gray, School of Oceanography, University of Washington, Box 355351, Seattle, WA 98195. E-mail: alison@ocean.washington.edu

A comment/reply has been published regarding this article and can be found at http://journals.ametsoc.org/doi/abs/10.1175/JPO-D-14-0127.1 and http://journals.ametsoc.org/doi/abs/10.1175/JPO-D-14-0215.1

Save