FY 1991

Oceanic event during the 1986–1987 El Niño

Zongshan, W., Z. Emei, J.M. Toole, L.J. Mangum, X. Bochang, and Y. Keqi

In Air-Sea Interaction in Tropical Western Pacific, Proceedings, US-PRC International TOGA Symposium, China Ocean Press, Beijing, 1988, 15–26 (1990)

In this paper, the oceanic event of the generation, development and decay of the 1986-1987 El Niño, is analyzed according to the data obtained in four cruises of the Sino-US joint air-sea interaction studies in the Western Tropical Pacific Ocean, together with the data of wind and SST provided by NOAA and that of sea level presented by Dr. Wyrtki of the University of Hawaii. It is pointed out that the 1986-1987 El Niño is a little bit stronger than the medium. The macroscropic variations of SSTs and sea levels are synchronous and similar. Meanwhile, they relate to the features of wind fields. The variations of subsurface temperature structures corresponded to the eastward transport of the warm water in the upper layer and the structures and directions of the current system changed extraordinarily in the western tropical Pacific during this El Niño. In the precursor of the event, SEC was strong and the warm water piled up in the western Pacific. In the onset phase, a wide-range (12.5° lat) eastward current was formed, resulting in the eastward transport of the warm water. In the decline phase, NECC became weak and SECC became strong. After the El Niño ended the ocean was in dynamical adjustment and the westward currents occupied a wide- range area (about 12° lat) near the equator. During this El Niño, total eastward volume transport in the western tropical Pacific is 11.4 × 10m which is 1/3 greater than that of the 1976 El Niño and about 2/5 less than that of the 1982/1983 El Niño.