Assessing ENSO Simulations and Predictions Using Adjoint Ocean State Estimation

Dietmar Dommenget Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California

Search for other papers by Dietmar Dommenget in
Current site
Google Scholar
PubMed
Close
and
Detlef Stammer Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California

Search for other papers by Detlef Stammer in
Current site
Google Scholar
PubMed
Close
Restricted access

We are aware of a technical issue preventing figures and tables from showing in some newly published articles in the full-text HTML view.
While we are resolving the problem, please use the online PDF version of these articles to view figures and tables.

Abstract

Simulations and seasonal forecasts of tropical Pacific SST and subsurface fields that are based on the global Consortium for Estimating the Circulation and Climate of the Ocean (ECCO) ocean-state estimation procedure are investigated. As compared to similar results from a traditional ENSO simulation and forecast procedure, the hindcast of the constrained ocean state is significantly closer to observed surface and subsurface conditions. The skill of the 12-month lead SST forecast in the equatorial Pacific is comparable in both approaches. The optimization appears to have better skill in the SST anomaly correlations, suggesting that the initial ocean conditions and forcing corrections calculated by the ocean-state estimation do have a positive impact on the predictive skill. However, the optimized forecast skill is currently limited by the low quality of the statistical atmosphere. Progress is expected from optimizing a coupled model over a longer time interval with the coupling statistics being part of the control vector.

Current affiliation: Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Kiel, Germany

Current affiliation: Institut für Meereskunde, Zentrum für Meeres-und Klimaforschung, Universität Hamburg, Hamburg, Germany

Corresponding author address: Dietmar Dommenget, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Düsternbrooker Weg 20, 24015 Kiel, Germay. Email: ddommenget@ifm.uni-kiel.de

Abstract

Simulations and seasonal forecasts of tropical Pacific SST and subsurface fields that are based on the global Consortium for Estimating the Circulation and Climate of the Ocean (ECCO) ocean-state estimation procedure are investigated. As compared to similar results from a traditional ENSO simulation and forecast procedure, the hindcast of the constrained ocean state is significantly closer to observed surface and subsurface conditions. The skill of the 12-month lead SST forecast in the equatorial Pacific is comparable in both approaches. The optimization appears to have better skill in the SST anomaly correlations, suggesting that the initial ocean conditions and forcing corrections calculated by the ocean-state estimation do have a positive impact on the predictive skill. However, the optimized forecast skill is currently limited by the low quality of the statistical atmosphere. Progress is expected from optimizing a coupled model over a longer time interval with the coupling statistics being part of the control vector.

Current affiliation: Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Kiel, Germany

Current affiliation: Institut für Meereskunde, Zentrum für Meeres-und Klimaforschung, Universität Hamburg, Hamburg, Germany

Corresponding author address: Dietmar Dommenget, Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Düsternbrooker Weg 20, 24015 Kiel, Germay. Email: ddommenget@ifm.uni-kiel.de

Save
  • Arakawa, A., and V. R. Lamb, 1977: Computational design of the basic dynamical processes of the UCLA general circulation model. Methods of Computational Physics, J. Chang, Ed., Vol. 17, Academic Press, 174–265.

    • Search Google Scholar
    • Export Citation
  • Barnett, T. P., N. Graham, S. Pazan, W. White, M. Latif, and M. Flügel, 1993: ENSO and ENSO-related predictability. Part I: Prediction of equatorial Pacific sea surface temperature with a hybrid coupled ocean–atmosphere Model. J. Climate, 6 , 15451566.

    • Search Google Scholar
    • Export Citation
  • Frankignoul, C., 1999: A cautionary note on the use of statistical atmospheric models in the middle latitudes: Comments on “Decadal variability in the North Pacific as simulated by a hybrid coupled model.”. J. Climate, 12 , 18711872.

    • Search Google Scholar
    • Export Citation
  • Galanti, E., E. Tziperman, M. Harrison, A. Rosati, and Z. Sirkes, 2003: A study of ENSO prediction using a hybrid–coupled model and the adjoint method for data assimilation. Mon. Wea. Rev, 131 , 27482764.

    • Search Google Scholar
    • Export Citation
  • Ji, M., and A. Leetmaa, 1997: Impact of data assimilation on ocean initialization and El Ninõ prediction. Mon. Wea. Rev, 125 , 742753.

    • Search Google Scholar
    • Export Citation
  • Ji, M., A. Leetmaa, and J. Derber, 1995: An ocean analysis system for seasonal to interannual climate studies. Mon. Wea. Rev, 123 , 460481.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc, 77 , 437471.

  • Large, W. G., J. C. McWilliams, and S. C. Doney, 1994: Oceanic vertical mixing: A review and a model with non-local boundary layer parameterization. Rev. Geophys, 32 , 363403.

    • Search Google Scholar
    • Export Citation
  • Lee, T., J-P. Boulanger, A. Foo, L-L. Fu, and R. Giering, 2000: Data assimilation by an intermediate coupled ocean–atmosphere model: Application to the 1997–1998 El Niño. J. Geophys. Res, 105 , 2606326087.

    • Search Google Scholar
    • Export Citation
  • Levitus, S., and T. Boyer, 1994: Temperature. Vol. 4. World Ocean Atlas 1994, NOAA Atlas NESDIS 4, 117 pp.

  • Levitus, S., R. Burgett, and T. Boyer, 1994: Salinity. Vol. 3. World Ocean Atlas 1994, NOAA Atlas NESDIS 3, 99 pp.

  • Marotzke, J., R. Giering, Q. K. Zhang, D. Stammer, C. N. Hill, and T. Lee, 1999: Construction of the adjoint MIT ocean general circulation model and application to Atlantic heat transport sensitivity. J. Geophys. Res, 104 , 2952929548.

    • Search Google Scholar
    • Export Citation
  • Marshall, J., A. Adcroft, C. Hill, L. Perelman, and C. Heisey, 1997a: A finite-volume incompressible Navier–Stokes model for studies of the ocean on parallel computers. J. Geophys. Res, 102 (C3) 57535766.

    • Search Google Scholar
    • Export Citation
  • Marshall, J., C. Hill, L. Perelman, and A. Adcroft, 1997b: Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling. J. Geophys. Res, 102 (C3) 57335752.

    • Search Google Scholar
    • Export Citation
  • McPhaden, M. J., and Coauthors, 1998: The Tropical Ocean–Global Atmosphere observation system: A decade of progress. J. Geophys. Res, 103 (C7) 1416914240.

    • Search Google Scholar
    • Export Citation
  • Reynolds, R. W., and T. M. Smith, 1994: Improved global sea surface temperature analyses using optimum interpolation. J. Climate, 7 , 929948.

    • Search Google Scholar
    • Export Citation
  • Segschneider, J., D. L. T. Anderson, and T. N. Stockdale, 2000: Toward the use of altimetry for operational seasonal forecasting. J. Climate, 13 , 31153138.

    • Search Google Scholar
    • Export Citation
  • Stammer, D., C. Wunsch, I. Fukumori, and J. Marshall, 2002a: State estimation improves prospects for ocean resreach. Eos, Trans. Amer. Geophys. Union,83 (27), pp. 289, 294–295.

    • Search Google Scholar
    • Export Citation
  • Stammer, D., and Coauthors, 2002b: The global ocean circulation during 1992–1997, estimated from ocean observations and a general circulation model. J. Geophys. Res.,107, 3118, doi:10.1029/ 2001JC000888.

    • Search Google Scholar
    • Export Citation
  • Stammer, D., and Coauthors, 2003: Volume, heat and freshwater transports of the global ocean circulation 1993–2000, estimated from a general circulation model constrained by WOCE data. J. Geophys. Res.,108, 3175, doi:10.1029/2001JC000937.

    • Search Google Scholar
    • Export Citation
  • Stammer, D., K. Ueyoshi, A. Köhl, W. B. Large, S. Josey, and C. Wunsch, 2004: Estimating air–sea fluxes of heat, freshwater and momentum through global ocean data assimilation. J. Geophys. Res, 109 .C05023, doi:10.1029/2003JC002082.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 367 158 63
PDF Downloads 118 59 1