Ocean Dynamics

, Volume 56, Issue 5, pp 543–567

Impact of partial steps and momentum advection schemes in a global ocean circulation model at eddy-permitting resolution

Authors

    • Laboratoire des Ecoulements Géophysiques et Industriels
  • Gurvan Madec
    • Laboratoire d’Océanographie Dynamique et de Climatologie
  • Thierry Penduff
    • Laboratoire des Ecoulements Géophysiques et Industriels
  • Jean-Marc Molines
    • Laboratoire des Ecoulements Géophysiques et Industriels
  • Anne-Marie Treguier
    • Laboratoire de Physique des OcéansIfremer Centre de Brest
  • Julien Le Sommer
    • Laboratoire des Ecoulements Géophysiques et Industriels
  • Aike Beckmann
    • Department of Physical Sciences, Division of GeophysicsUniversity of Helsinki
  • Arne Biastoch
    • IfM-GEOMAR, Leibniz-Institut für Meereswissenschaften an der Universität Kiel
  • Claus Böning
    • IfM-GEOMAR, Leibniz-Institut für Meereswissenschaften an der Universität Kiel
  • Joachim Dengg
    • IfM-GEOMAR, Leibniz-Institut für Meereswissenschaften an der Universität Kiel
  • Corine Derval
    • MERCATOR-Ocean
  • Edmée Durand
    • MERCATOR-Ocean
  • Sergei Gulev
    • Shirshov Institut of OceanographyRussian Academy of Science
  • Elizabeth Remy
    • MERCATOR-Ocean
  • Claude Talandier
    • Laboratoire d’Océanographie Dynamique et de Climatologie
  • Sébastien Theetten
    • Laboratoire de Physique des OcéansIfremer Centre de Brest
  • Mathew Maltrud
    • Fluid Dynamics GroupLos Alamos National Laboratory
  • Julie McClean
    • Scripps Institution of Oceanography, UCSD
  • Beverly De Cuevas
    • National Oceanography Centre
Original paper

DOI: 10.1007/s10236-006-0082-1

Cite this article as:
Bernard, B., Madec, G., Penduff, T. et al. Ocean Dynamics (2006) 56: 543. doi:10.1007/s10236-006-0082-1

Abstract

Series of sensitivity tests were performed with a z-coordinate, global eddy-permitting (1/4°) ocean/sea-ice model (the ORCA-R025 model configuration developed for the DRAKKAR project) to carefully evaluate the impact of recent state-of-the-art numerical schemes on model solutions. The combination of an energy–enstrophy conserving (EEN) scheme for momentum advection with a partial step (PS) representation of the bottom topography yields significant improvements in the mean circulation. Well known biases in the representation of western boundary currents, such as in the Atlantic the detachment of the Gulf Stream, the path of the North Atlantic Current, the location of the Confluence, and the strength of the Zapiola Eddy in the south Atlantic, are partly corrected. Similar improvements are found in the Pacific, Indian, and Southern Oceans, and characteristics of the mean flow are generally much closer to observations. Comparisons with other state-of-the-art models show that the ORCA-R025 configuration generally performs better at similar resolution. In addition, the model solution is often comparable to solutions obtained at 1/6 or 1/10° resolution in some aspects concerning mean flow patterns and distribution of eddy kinetic energy. Although the reasons for these improvements are not analyzed in detail in this paper, evidence is shown that the combination of EEN with PS reduces numerical noise near the bottom, which is likely to affect current–topography interactions in a systematic way. We conclude that significant corrections of the mean biases presently seen in general circulation model solutions at eddy-permitting resolution can still be expected from the development of numerical methods, which represent an alternative to increasing resolution.

Keywords

Global oceanEddy-permitting ocean modelMomentum advection schemePartial step topographyEddy/topography interactions

Copyright information

© Springer-Verlag 2006