The diagnosis for the tropical Pacific Ocean conditions in 1990

In this paper, on the basis of the observational hydrographic data obtained from the eighth cruise of PRC-USA bilateral air-sea interaction program, and combined with the sea surface temperature (SST) charts provided by NOAA, the data obtained from moored thermistor chains supplied by L. J. Mangum and sea level data provided by K. Wyrtki, the ocean conditions since October, 1989 in the western tropical Pacific are exposed, which indicate that 1990 is a year with weak El Nino event similar to the 1980 El Nino event, and the North Equatorial Countercurrent (NECC) has made a good contribution to the propagation of warm water from the Western to the Central and Eastern Pacific, a characteristic similar to that of the 1976 El Nino event. The 1990 weak El Nino event will soon fall into decay.