- Conference Proceedings Paper
The historical records of the trade winds in the tropical Pacific may have a systematic bias towards higher speed due to the change of observational instruments. The observations of sea level height and sea level pressure suggests the records of the trade winds need to be corrected by a reduction rate, and the trade winds may have become weaker in recent decades. Forced with the corrected winds from 1955 to 1994, the simulation of an ocean general circulation model (OGCM) indicates that the temperature increases in the tropical Pacific (10aS-10aN) near the surface and in the eastern tropical Pacific above 400m, while it decreases in the thermocline of the western tropical Pacific. The simulated temperature trends are consistent with the objectively analyzed data based on the historic ocean temperature observations between 1955 and 1994. The OGCM simulation also suggests that, in the central and western tropical Pacific, the surface warming is related to the reduction of the off-equatorial current and South Equatorial Current, and the cooling in the thermocline is associated with the reduction of equatorward convergent flow. In the eastern tropical Pacific, the warming appears to be related to the reduction of upwelling. The reduction of these currents may in turn be associated with the weakening of the trade winds.