ASSIMILATION OF SUBSURFACE THERMAL DATA INTO A SIMPLE OCEAN MODEL FORTHE INITIALIZATION OF AN INTERMEDIATE TROPICAL COUPLED OCEAN-ATMOSPHERE FORECAST MODEL

An adjoint variational assimilation technique is used to assimilate ob servations of both the oceanic state and wind stress data into an inte rmediate coupled ENSO prediction model. This method of initialization is contrasted with the more usual method, which uses only wind stress data to establish the initial state of the ocean. It is shown that oce an temperature data has a positive impact on the prediction skill in s uch models. On the basis of hindcasts for the period 1982-91, it is sh own that NINO3 SST anomaly correlations greater than 0.7 can be obtain ed for hindcasts of duration up to 13 months and greater than 0.6 up t o 16 months. There are also clear indications of skill at two years.