The characteristics of the convergence zone at the eastern edge of the equatorial Pacific warm pool are studied using a compilation of in-situ current and salinity measurements during the period 1992--2001. The displacement of the convergence zone is observed, for the first time, as far west as 140¿E in the far western Pacific, mainly during La Ni¿a periods, and near 140¿W in the central Pacific during the 1997--98 El Ni¿o. The convergence zone may be associated with a salinity front dividing the fresh waters of the warm pool from the salty waters upwelled in the central equatorial Pacific. Despite a zonal displacement ranging over about one fifth of the equatorial circumference of the earth, the characteristics of the main parameters involved in the air-sea interactions are nearly constant on each side of the convergence zone/salinity front. These results suggest that coupled models used for El Ni¿o research and forecasting should be able to reproduce these important features.