Prévisions des Evénements EL-Niño
ENSO prediction with intermediate coupled models of the Tropical Pacific
We present prediction runs with 2 intermediate ocean-atmosphere coupled models of the tropical Pacific. The two models (Model 1 and Model 2) differ solely from the atmospheric component. The ocean component is a 3 baroclinic mode linear model. Model 1 uses a "shallow-water" model for the atmospheric part (Gill's type). Model 2 uses a statistical atmospheric model based on the SVD decomposition of observed sea surface temperature (SST) and wind stress anomalies. Models 1 and 2 are detailed in Dewitte (2000), Gushchina et al. (2000) and Dewitte et al. (2002). Initial conditions for the prediction runs are produced in a coupled mode by nudging the observed winds (FSU winds for the period 1961-1992, ERS1-2 winds from may 1992 until september 2000, QuikSCAT winds from october 2000) to the simulated winds as in Chen et al. (1995). Forecasts are an ensemble average of 12 prediction runs starting from initial condictions obtained by adding random noise to the wind forcing like in Kirtman and Schopf (1998).
Predictions for an initialization with observations in February 2009:
|Model 1 (dynamical atmosphere)||Model 2 (statistical atmosphere)|
|Predicted SST anomalies||Predicted SST anomalies|
- Chen, D., S. E. Zebiak, A. J. Busalacchi, and M. A. Cane, 1995: An improved procedure for El Niño forecasting: Implication for predictability. Science, 269, 1699-1702.
- Dewitte B., 2000: Sensitivity of an intermediate coupled ocean-atmosphere model of the tropical Pacific to its oceanic vertical structure. J. Climate, 13, 2363-2388.
- Dewitte B., D. Gushchina, Y. duPenhoat and S. Lakeev, 2002: On the importance of subsurface variability for ENSO simulation and prediction with intermediate coupled models of the Tropical Pacific: A case study for the 1997-1998 El Niño. Geoph. Res. Lett., vol. 29, no. 14, 1666, 10.1029/2001GL014452.
- Gushchina D. Yu, B. Dewitte and M. A. Petrossiants, 2000: A coupled ocean-atmosphere model of tropical Pacific : The forecast of the 1997-1998 El Niño Southern Oscillation. Izvestiya atmospheric and oceanic physics. 36 (5): 533-554.
- Kirtman, B. P. and P. S. Schopf, 1998: Decadal variability in ENSO predictability an prediction, J. Climate, 11, 2804-2822.