El Niño-Like Events Observed in the Tropical Pacific

Abstract

The data provided by ships of opportunity operated by SURTROPAC Group (Centre ORSTOM de Nouméa) are used to study surface temperature and salinity. In 1979 and 1982, negative anomalies of salinity occurred in the equatorial western Pacific. These are usually induced by El Niño events, although no El Niño was noticed in the eastern Pacific during the beginning of the year. However, along the Tahiti–Panama shipping route, the warm season in 1979 and 1982 lasted longer than usual. Empirical orthogonal analysis applied to the surface temperature along shipping routes in the eastern and central Pacific reveal other events with the same signature as the 1976 El Niño. A weak event occurred in 1979 and we can also see the beginning of the 1982 major event. Eastern, central and western anomalies are significant correlated.