Observation of Spatial Variability of Diurnal Thermocline and Rain-Formed Halocline in the Western Pacific Warm Pool

High-resolution measurements of temperature and salinity were made in the near-surface layer of the ocean during the Tropical Oceans-Global Atmosphere Coupled Ocean-Atmosphere Response Experiment, using probes mounted on the bow of the R/V Moana Wave. Because of surface waves and pitching of the vessel, the bow probes profiled the near-surface layer of the ocean within depths of 0–4.0 m. In the near-surface layer of the ocean in the western Pacific warm pool, strong variability of temperature and salinity produced by diurnal heating and/or rain was often observed. The contoured density field revealed cases of pronounced spatial variability. The shallow diurnal thermocline and rain-formed halocline are subject to perturbations that sometimes look like large amplitude internal waves. Possible sources of the internal waves in the near-surface layer of the ocean are discussed