Improving ENSO simulations and predictions through
the ECCO ocean state estimation 

Dietmar Dommenget and Detlef Stammer

The global ECCO ocean state estimation procedure is used to simulate 
and forecasts of tropical Pacific SST and sub-surface fields on seasonal
time scale. As compared to a traditional ENSO assimilation and prediction
procedures, the hindcast of the constrained ocean state is much closer to 
observed conditions. The skill of the 12 month lead SST forecast in the
equatorial Pacific appears to be similar in both assimilation, but
the optimizations leads to better skills in the SST anomaly correlations. 
Although our current forecast system is strongly limited by the estimation 
of atmospheric forcing corrections, the results see to suggest that
the forecast system would benefit if adoint optimizations are performed
with coupled ocean-atmosphere systems in which the coupling is
part of the control vectors of the adjoint optimization.