Sensitivity of equatorial Pacific and Indian Ocean watermasses to the position of the Indonesian throughflow

The sensitivity of the thermal structure of the equatorial Pacific and Indi an Ocean pycnoclines to a model's representation of the Indonesian Straits connecting the two basins is investigated. Two integrations are performed u sing the: global HOPE ocean model. The. initial conditions and surface forc ing for both cases are identical; the only difference between the runs is t hat one has an opening for the Indonesian Straits which spans the equator o n the Pacific side, and the other has an opening which lies fully north of the equator. The resulting sensitivity throughout much of the upper ocean i s greater than 0.5 degrees C for both the equatorial Indian and Pacific. A realistic simulation of net Indonesian Throughflow (ITF) transport (measure d in Sverdrups) is not sufficient for an adequate simulation of equatorial watermasses. The ITF mist also contain a realistic admixture of northern an d southern Pacific source water.