An array of Inverted Echo Sounders, subsurface pressure gauges, and tide gauges has been maintained between 9deg S and 10deg N near 160deg W for a period of five years from February, 1985. In this project, the P.I.'s will analyze the five-year data set, focusing on the observation of the 1986-87 El Nino event, the 1988 cold event, and the general related ocean response, as well as the specific observation of tropical instability waves, and their changes during these events.