• Badin, G., , and R. G. Williams, 2010: On the buoyancy forcing and residual circulation in the Southern Ocean: The feedback from Ekman and eddy transfer. J. Phys. Oceanogr., 40, 295310, doi:10.1175/2009JPO4080.1.

    • Search Google Scholar
    • Export Citation
  • Ballarotta, M., , S. Drijfhout, , T. Kuhlbrodt, , and K. Döös, 2013: The residual circulation of the Southern Ocean: Which spatio-temporal scales are needed? Ocean Modell., 64, 4655, doi:10.1016/j.ocemod.2013.01.005.

    • Search Google Scholar
    • Export Citation
  • Döös, K., , and D. J. Webb, 1994: The Deacon cell and the other meridional cells of the Southern Ocean. J. Phys. Oceanogr., 24, 429442, doi:10.1175/1520-0485(1994)024<0429:TDCATO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Döös, K., , J. Nilsson, , J. Nycander, , L. Brodeau, , and M. Ballarotta, 2012: The World Ocean thermohaline circulation. J. Phys. Oceanogr., 42, 14451460, doi:10.1175/JPO-D-11-0163.1.

    • Search Google Scholar
    • Export Citation
  • Durack, P. J., , S. E. Wijffels, , and R. J. Matear, 2012: Ocean salinities reveal strong global water cycle intensification during 1950 to 2000. Science, 336, 455458, doi:10.1126/science.1212222.

    • Search Google Scholar
    • Export Citation
  • Ferrari, R., , and D. Ferreira, 2011: What processes drive the ocean heat transport? Ocean Modell., 38, 171186, doi:10.1016/j.ocemod.2011.02.013.

    • Search Google Scholar
    • Export Citation
  • Gent, P. R., , J. Willebrand, , T. J. McDougall, , and J. C. McWilliams, 1995: Parameterizing eddy-induced tracer transports in ocean circulation models. J. Phys. Oceanogr., 25, 463474, doi:10.1175/1520-0485(1995)025<0463:PEITTI>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Graham, F. S., , and T. J. McDougall, 2013: Quantifying the nonconservative production of Conservative Temperature, potential temperature, and entropy. J. Phys. Oceanogr., 43, 838862, doi:10.1175/JPO-D-11-0188.1.

    • Search Google Scholar
    • Export Citation
  • Griffies, S. M., 2004: Fundamentals of Ocean Climate Models.Princeton University Press, 518 pp.

  • Hanawa, K., , and L. D. Talley, 2001: Mode waters. Ocean Circulation and Climate: Observing and Modelling the Global Ocean, International Geophysics Series, Vol. 77, Academic Press, 373–386.

  • IOC, SCOR, and IAPSO, 2010: The international thermodynamic equation of seawater—2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission Manuals and Guides 56, 196 pp. [Available online at http://www.teos-10.org/pubs/TEOS-10_Manual.pdf.]

  • Iudicone, D., , G. Madec, , and T. J. McDougall, 2008: Water-mass transformations in a neutral density framework and the key role of light penetration. J. Phys. Oceanogr., 38, 13571376, doi:10.1175/2007JPO3464.1.

    • Search Google Scholar
    • Export Citation
  • Kjellsson, J., , K. Döös, , F. B. Laliberté, , and J. D. Zika, 2014: The atmospheric general circulation in thermodynamical coordinates. J. Atmos. Sci., 71, 916–928, doi:10.1175/JAS-D-13-0173.1.

    • Search Google Scholar
    • Export Citation
  • Marsh, R., 2000: Recent variability of the North Atlantic thermohaline circulation inferred from surface heat and freshwater fluxes. J. Climate, 13, 32393260, doi:10.1175/1520-0442(2000)013<3239:RVOTNA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Marshall, D., 1997: Subduction of water masses in an eddying ocean. J. Mar. Res., 55, 201222, doi:10.1357/0022240973224373.

  • Marshall, J., , D. Jamous, , and J. Nilsson, 1999: Reconciling thermodynamic and dynamic methods of computation of water-mass transformation rates. Deep-Sea Res. I, 46, 545572, doi:10.1016/S0967-0637(98)00082-X.

    • Search Google Scholar
    • Export Citation
  • McDougall, T. J., 2003: Potential enthalpy: A conservative oceanic variable for evaluating heat content and heat fluxes. J. Phys. Oceanogr., 33, 945963, doi:10.1175/1520-0485(2003)033<0945:PEACOV>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • McDougall, T. J., , and P. M. Barker, 2011: Getting started with TEOS-10 and the Gibbs Seawater (GSW) oceanographic toolbox. SCOR/IAPSO WG127 Rep., 34 pp. [Available online at http://www.teos-10.org/pubs/Getting_Started.pdf.]

  • McDougall, T. J., , D. R. Jackett, , F. J. Millero, , R. Pawlowicz, , and P. M. Barker, 2012: A global algorithm for estimating Absolute Salinity. Ocean Sci., 8, 11231134, doi:10.5194/os-8-1123-2012.

    • Search Google Scholar
    • Export Citation
  • McDougall, T. J., , S. Groeskamp, , and S. M. Griffies, 2014: On geometrical aspects of interior ocean mixing. J. Phys. Oceanogr., doi:10.1175/JPO-D-13-0270.1, in press.

  • Millero, F. J., , R. Feistel, , D. G. Wright, , and T. J. McDougall, 2008: The composition of standard seawater and the definition of the reference-composition salinity scale. Deep-Sea Res. I, 55, 5072, doi:10.1016/j.dsr.2007.10.001.

    • Search Google Scholar
    • Export Citation
  • Nikurashin, M., , and R. Ferrari, 2013: Overturning circulation driven by breaking internal waves in the deep ocean. Geophys. Res. Lett., 40, 31333137, doi:10.1002/grl.50542.

    • Search Google Scholar
    • Export Citation
  • Nurser, A. J. G., , and R. Marsh, 1998: Water mass transformation theory and the meridional overturning streamfunction. International WOCE Newsletters, No. 31, WOCE International Project Office, Southampton, United Kingdom, 36–39.

  • Nurser, A. J. G., , and M.-M. Lee, 2004: Isopycnal averaging at constant height. Part I: The formulation and a case study. J. Phys. Oceanogr., 34, 27212739, doi:10.1175/JPO2649.1.

    • Search Google Scholar
    • Export Citation
  • Nurser, A. J. G., , R. Marsh, , and R. G. Williams, 1999: Diagnosing water mass formation from air–sea fluxes and surface mixing. J. Phys. Oceanogr., 29, 14681487, doi:10.1175/1520-0485(1999)029<1468:DWMFFA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Nycander, J., , J. Nilsson, , K. Döös, , and G. Broström, 2007: Thermodynamic analysis of ocean circulation. J. Phys. Oceanogr., 37, 20382052, doi:10.1175/JPO3113.1.

    • Search Google Scholar
    • Export Citation
  • Pacanowski, R., 1996: MOM2 version 2 documentation, user’s guide, and reference manual. NOAA/GFDL Ocean Tech. Rep. 3.2, 329 pp. [Available online at http://gfdl.noaa.gov/cms-filesystem-action/model_development/ocean/manual2.2.pdf.]

  • Ridgway, K. R., , and J. Dunn, 2003: Mesoscale structure of the mean East Australian Current system and its relationship with topography. Prog. Oceanogr., 56, 189222, doi:10.1016/S0079-6611(03)00004-1.

    • Search Google Scholar
    • Export Citation
  • Ridgway, K. R., , J. R. Dunn, , and J. L. Wilkin, 2002: Ocean interpolation by four-dimensional weighted least squares—Application to the waters around Australasia. J. Atmos. Oceanic Technol., 19, 13571375, doi:10.1175/1520-0426(2002)019<1357:OIBFDW>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Sijp, W. P., , M. Bates, , and M. H. England, 2006: Can isopycnal mixing control the stability of the thermohaline circulation in ocean climate models? J. Climate, 19, 56375651, doi:10.1175/JCLI3890.1.

    • Search Google Scholar
    • Export Citation
  • Sloyan, B. M., , and S. R. Rintoul, 2000: Estimates of area-averaged diapycnal fluxes from basin-scale budgets. J. Phys. Oceanogr., 30, 23202341, doi:10.1175/1520-0485(2000)030<2320:EOAADF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Sloyan, B. M., , and S. R. Rintoul, 2001: The Southern Ocean limb of the global deep overturning circulation. J. Phys. Oceanogr., 31, 143173, doi:10.1175/1520-0485(2001)031<0143:TSOLOT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Speer, K. G., 1993: Conversion among North Atlantic surface water types. Tellus, 45A, 7279, doi:10.1034/j.1600-0870.1993.00006.x.

  • Speer, K. G., , and E. Tziperman, 1992: Rates of water mass formation in the North Atlantic Ocean. J. Phys. Oceanogr., 22, 93104, doi:10.1175/1520-0485(1992)022<0093:ROWMFI>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Walin, G., 1982: On the relation between sea-surface heat flow and thermal circulation in the ocean. Tellus, 34, 187195, doi:10.1111/j.2153-3490.1982.tb01806.x.

    • Search Google Scholar
    • Export Citation
  • Zika, J. D., , M. H. England, , and W. P. Sijp, 2012: The ocean circulation in thermohaline coordinates. J. Phys. Oceanogr., 42, 708724, doi:10.1175/JPO-D-11-0139.1.

    • Search Google Scholar
    • Export Citation
  • Zika, J. D., , W. P. Sijp, , and M. H. England, 2013: Vertical heat transport by the ocean circulation and the role of mechanical and haline forcing. J. Phys. Oceanogr., 43, 20952112, doi:10.1175/JPO-D-12-0179.1.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 30 30 14
PDF Downloads 20 20 9

The Representation of Ocean Circulation and Variability in Thermodynamic Coordinates

View More View Less
  • 1 CSIRO Wealth from Oceans National Research Flagship, and Institute for Marine and Atmospheric Studies, University of Tasmania, Hobart, Tasmania, Australia
  • 2 University of Southampton, National Oceanography Centre, Southampton, United Kingdom
  • 3 School of Mathematics and Statistics, University of New South Wales, Sydney, New South Wales, Australia
  • 4 CSIRO Wealth from Oceans National Research Flagship, and Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia
  • 5 Department of Physics, University of Toronto, Toronto, Ontario, Canada
© Get Permissions
Restricted access

Abstract

The ocean’s circulation is analyzed in Absolute Salinity SA and Conservative Temperature Θ coordinates. It is separated into 1) an advective component related to geographical displacements in the direction normal to SA and Θ isosurfaces and 2) into a local component, related to local changes in SA–Θ values, without a geographical displacement. In this decomposition, the sum of the advective and local components of the circulation is equivalent to the material derivative of SA and Θ. The sum is directly related to sources and sinks of salt and heat. The advective component is represented by the advective thermohaline streamfunction . After removing a trend, the local component can be represented by the local thermohaline streamfunction . Here, can be diagnosed using a monthly averaged time series of SA and Θ from an observational dataset. In addition, and are determined from a coupled climate model. The diathermohaline streamfunction is the sum of and and represents the nondivergent diathermohaline circulation in SA–Θ coordinates. The diathermohaline trend, resulting from the trend in the local changes of SA and Θ, quantifies the redistribution of the ocean’s volume in SA–Θ coordinates over time. It is argued that the diathermohaline streamfunction provides a powerful tool for the analysis of and comparison among ocean models and observation-based gridded climatologies.

Corresponding author address: Sjoerd Groeskamp, CSIRO Wealth from Oceans National Research Flagship, Castray Esplanade, Hobart, TAS 7000, Australia. E-mail: sjoerd.groeskamp@csiro.au

Abstract

The ocean’s circulation is analyzed in Absolute Salinity SA and Conservative Temperature Θ coordinates. It is separated into 1) an advective component related to geographical displacements in the direction normal to SA and Θ isosurfaces and 2) into a local component, related to local changes in SA–Θ values, without a geographical displacement. In this decomposition, the sum of the advective and local components of the circulation is equivalent to the material derivative of SA and Θ. The sum is directly related to sources and sinks of salt and heat. The advective component is represented by the advective thermohaline streamfunction . After removing a trend, the local component can be represented by the local thermohaline streamfunction . Here, can be diagnosed using a monthly averaged time series of SA and Θ from an observational dataset. In addition, and are determined from a coupled climate model. The diathermohaline streamfunction is the sum of and and represents the nondivergent diathermohaline circulation in SA–Θ coordinates. The diathermohaline trend, resulting from the trend in the local changes of SA and Θ, quantifies the redistribution of the ocean’s volume in SA–Θ coordinates over time. It is argued that the diathermohaline streamfunction provides a powerful tool for the analysis of and comparison among ocean models and observation-based gridded climatologies.

Corresponding author address: Sjoerd Groeskamp, CSIRO Wealth from Oceans National Research Flagship, Castray Esplanade, Hobart, TAS 7000, Australia. E-mail: sjoerd.groeskamp@csiro.au
Save