The relationship between the vertical structures of ocean temperature and salinity and their concurrent signature in surface dynamic height anomalies are investigated along the 165 ¿E transequatorial section in the western Pacific Ocean. The data are from conductivity-temperature depth casts made during 28 oceanographic cruises mainly conducted during the 1984--1992 time period as part of the TOGA program. The analysis is based on empirical orthogonal functions that isolate the primary modes of variability, and some possible physical interpretations are suggested. The results show that the first six modes, explaining roughly 80% of the variance, display distinct vertical scales and exhibit coherent and observable signatures in dynamic height which reveal complex patterns in latitude and time. In addition, a method has been developed to reconstruct the temperature and salinity profiles from their signature in the surface dynamic height anomaly using the dominant EOFs. The method is new in the sense that no recourse is made to T-S relations. Residual errors in the vertical after reconstruction are lower than the intrinsic variability, and the method can successfully reproduce the variability at ENSO timescales. The residual error in dynamic height anomalies is lower than 1 dyn. cm in the equatorial belt, and of the order of 2--4 dyn. cm in the subtropics. The results demonstrate that sea level observations may be translate into temperature and salinity anomalies at depth. The implications for data assimilation in ocean models are discussed. ¿ 1999 American Geophysical Union