Development and testing of climate models for seasonal prediction for Australia
Meyers, G. Dr; Ph: (03) 6232 5208; Fax: (03) 6232 5123; gary.meyers@ml.csiro.au
Hunt, B. Mr; Ph: (03) 9586 7666; Fax: (03) 9586 7600; barrie.hunt@dar.csiro.au
Nicholls, N. Dr; Ph: (03) 9669 4407; Fax: (03) 9669 4660; nnn@bom.gov.au
Research Organisations: CSIRO Marine Research; GPO Box 1538, Hobart Tas 7001; CSIRO Atmospheric Research; PMB No 1, Aspendale Vic 3195; Bureau of Meteorology, Research Centre, GPO Box 1289K, Melbourne Vic 3001
Sponsor: LWRRDC, Land and Water Resources Research and Development Corporation
Objectives:
To develop and validate an experimental seasonal climate prediction system using coupled general circulation models of the ocean and the atmosphere (primary goal).
Through enhanced collaboration, advance the development of a numerical general circulation model (GCM) of the oceans (O) and the atmosphere (A) for seasonal forecasting of Australian climate by:
1. assessment of forecasts of Australian rainfall using a stand alone AGCM with predicted sea surface temperature (SST), and simulation of other weather variables with observed SST;
2. improvement of the existing OGCM in areas that have a strong influence on Australian rainfall, in particular the Indonesian seas and the Indian Ocean;
3. development of a prototype coupled OGCM-AGCM for seasonal prediction.
Methodology: Development of statistical methods to forecast global sea surface temperature up to three months in advance and to assess the accuracy of rainfall and other meteorological variables in a stand alone atmospheric general circulation model that responds to sea surface temperature. Application of hydrodynamics and thermodynamics to simulate the processes that control sea surface temperature in the tropical regions north of Australia, including the complex topography of islands, air-sea heat fluxes and tidal mixing. Experiment to develop protocols for coupling numerical models of the ocean and atmosphere.
Progress: The model is presently up and running. A number of experiments have been performed with a stand-alone atmosphere model and a stand-alone ocean model to test performance under idealised (perfect) forcing conditions. Successes and deficiencies have been identified in both models. For example, the atmospheric model can produce a very realistic simulation of Southern Oscillation Index but rainfall patterns over Australia can be inaccurate. The oceanic model very accurately simulates observed oceanic behaviour in tropical ocean, but doesn't perform well at higher latitudes. Strategies to improve the models are being developed. The coupled model is being run through a series of hindcast experiments to test its ability to predict SST patterns and atmospheric variables (both rainfall and SOI).
Period: starting date 1996-01; completion date 1998-12
Status: Project will be completed on schedule
Keywords: climate; models; weather forecasting; seasons
Publications:
Allan, R.J., Folland, C.K., Parker, D.E., Mann, M.E., Smith, I.N. and Basnett, T.A. (submitted). ENSO and large-scale modes of climatic variability in global instrumental data. Science.
Ansell, T. J., Reason, C.J.C. and Smith, I.N. (submitted). Evidence for decadal variability in southern Australian rainfall and relationships with regional pressure and sea surface temperature. International Journal of Climatology.
Frederiksen, C.S., Rowell, D.P., Balgovind, R. and Folland, C.K. (in press). Multidecadal simulations of Australian rainfall: The role of SSTs. Journal of Climate.
Godfrey, J.S. and Schiller, A. (1997). Tests of mixed-layer schemes and surface boundary conditions in an Ocean General Circulation Model, using the IMET flux data set. CSIRO Marine Laboratories Report No. 231.
Hunt, B.G. (1997). Prospects and problems for multi-seasonal predictions: some issues arising from a study of 1992. International Journal of Climatology 17, 137-154.
Hunt, B. G. (1997). Global climatic models: long-term predictions, annual to decadal. In: R. K. Munro and L.M. Leslie (eds). Climate Prediction for Agricultural and Resource Management. Australian Academy of Science Conference, Bureau of Resource Sciences Canberra, pp 31-44.
Hunt, B.G. and Hirst, A.C. (in press). Global climatic models and their potential for seasonal climatic forecasting. In: G. Hammer and C. Mitchell (eds). Applications of seasonal climate forecasting in agricultural and natural ecosystems - the Australian experience.
Hunt, B.G. (submitted). Multi-seasonal hindcasts for 1972-1992. Monthly Weather Review.
Masumoto, Y and Meyers, G. (submitted). Forced Rossby Waves in the Southern Tropical Indian Ocean. Journal of Geophysical Research.
Meyers, G. (1996). Variation of Indonesian throughflow and the El Niņo-Southern Oscillation. Journal of Geophysical Research 101, 12,255-12,263.
Schiller, A., Godfrey, J.S., McIntosh, P. and Meyers, G (1997). A Global Ocean General Circulation Model for climate variability studies. CSIRO Marine Laboratories Report No. 227.
Schiller, A., Godfrey, J.S., McIntosh, P., Meyers, G. and Wijffels, S.E. (in press). Seasonal near-surface dynamics and thermodynamics of the Indian Ocean and Indonesian throughflow, in a global ocean general circulation model. Journal of Physical Oceanography.
Schiller, A., Godfrey, J.S., McIntosh, P.C., Meyers, G. and Fiedler, R. (submitted). Interannual dynamics and thermodynamics of the Indo-Pacific Oceans. Journal of Physical Oceanography.
Schiller, A., Godfrey, J.S., McIntosh, P.C., Meyers, G., Fiedler, R. and Pigot, L. (1998). Modelling interannual variability in the Indian Ocean. WOCE Indian Ocean Workshop, University of New Orleans, New Orleans, September 1998.
Smith I.N., McIntosh, P., Ansell, T.J., Reason, C.J.C. and McInnes, K. (submitted). South-west Western Australian winter rainfall and its association with Indian Ocean climate variability, Climate Dynamics.
Stone, R., Smith, I.N. and McIntosh, P. (submitted). Statistical methods for deriving seasonal climate forecasts from GCMs. In: G. Hammer and C. Mitchell (eds) .Applications of seasonal climate forecasting in agricultural and natural ecosystems-the Australian experience.
Wilson, S.G. and Hunt, B.G. (1997). Impact of Greenhouse warming on El Niņo/Southern Oscillation behaviour in a high resolution coupled global climatic model. A research project commissioned by the Department of Environment, Sport and Territories, Australia. CSIRO Division of Atmospheric Research.
Zheng, X and Frederiksen, C.S. (submitted). Validating interannual variability induced by forcing in an ensemble of AGCM simulations. Journal of Climate.
