Two Modes of Salinity and Temperature Variation in the Surface Layer of the Pacific Warm Pool

The characteristics of temperature and salinity variation in the Pacific warm pool were investigated using Empirical Orthogonal Function (EOF) analysis on one year's temperature and salinity data in the surface layer (0–50 m) obtained from the Triangle Trans-Ocean Buoy Network (TRITON) buoy array. Two dominant modes of surface temperature and salinity variation were found. One is a positive correlation mode where temperature and salinity were scattered almost parallel to isopycnal lines in a T-S diagram, which has little effect on the density field. The other is a negative correlation mode where temperature and salinity were distributed across isopycnal lines, which has a substantial impact on the density field. In particular, we found that the negative correlation mode at 5°N, 156°E was predominant on a seasonal time scale and contributed to the surface dynamic height variation, and therefore to surface geostrophic current. This revised version was published online in July 2006 with corrections to the Cover Date.