The Pacanowski-Philander (PP) and Mellor-Yamada (MY) parameterization models of vertical mixing by turbulent processes were embedded in the Geophysical Fluid Dynamics Laboratory high-resolution ocean general circulation model of the tropical Pacific Ocean. All other facets of the numerical simulations were the same. Simulations were made for the 1987--1988 period. At the equator the MY simulation produced near-surface temperatures more uniform with depth, a deeper thermocline, a deeper core speed of the Equatorial Undercurrent, and a South Equatorial Current with greater vertical thickness compared with that computed with the PP method. Along 140¿W, between 5¿N and 10¿N, both simulations were the same. Moored-buoy current and temperature observations had been recorded by the Pacific Marine Environmental Laboratory at three sites (165¿E, 140¿W, 110¿W) along the equator and at three sites (5¿N, 7¿N, 9¿N) along 140¿W. Simulated temperatures were lower than those observed in the near-surface layer and higher than those observed in the thermocline. Temperature simulations were in better agreement with observations compared to current simulations. At the equator, PP current and temperature simulations were more representative of observations than MY simulations. ¿ American Geophysical Union 1995