Seasonal and interannual variability of sea surface temperatures in the Tropical Pacific, 1969-1991

Water sample data derived from a ship-of-opportunity program are used to describe changes in sea surface temperature (SST) for the Tropical Pacific. Time series up to 23 y long (1969-1991) allow four selected shipping tracks crossing the equator near 155°E, and 160, 140 and 100°W. Poleward of 6-8° latitude, the seasonal variability increases, reflecting the growing impact of surface thermal forcing. Within 6-8° latitude, the seasonal and interannual variabilities in the Eastern Pacific are of the same order of magnitude, whereas in the Western Pacific the interannual variability is 2-10 times greater than the seasonal variability. Maximum interannual variability appears trapped at and along the equator, in relation with the occurrence of El Nino (1976, 1982-1983, 1987 and 1991) and La Nina (1988-1989) events. Complementing various other local investigations, the present study enables basin-scale SST changes to be documented in a concise fashion. (Résumé d'auteur

Mechanisms of subsurface thermal structure and sea surface thermohaline variabilities in the southwestern tropical Pacific during 1975-85

Major features of the southwestern tropical Pacific (SWTP), defined between 160E-140W and 24S-10S, are brought to light through analysis of surface water samples (23000) and temperature/depth observations (8500), both collected by ship opportunity programs during the 1979-85 period. The mean vertical thermal structure (and its related parameters), mean sea surface temperature (SST) and salinity (SSS) are first portrayed, to further quantify the 1979-85 variability. It is demonstrated that the observed seasonal and interannual variabilities, the latter being associated with the strong 1982-83 El Nino Southern Oscillation (ENSO) event, are mostly governed by specific mechanisms involving varying wind field and rainfall regimes

Proceedings of US - PRC international TOGA symposium

Major features of the South Western Tropical Pacific are brought to light through analysis of sea surface salinity samples (23000) and temperature profiles (8500) gathered to study the 1979-1985 period. It is shown that the surface and subsurface oceanic variability is schematically dominated both by the seasonal cycle and the strong 1982-1983 ENSO signal. Specific mechanisms responsible for the ENSO impact upon a) the vertical thermal structure and its related parameters, b) the sea surface temperature, and c) the sea surface salinity are identified and tested. (Résumé d'auteur

Observations of the Equatorial intermediate current in the Western Pacific ocean (165°E)

Direct current measurements (0-600 m; re. 600 m) were carried out every six months from January 1984 to June 1986 in the Western Tropical Pacific Ocean (165°E) from 20°S to 10°N. The Equatorial Intermediate Current (EIC) occurred beneath the Equatorial Undercurrent (EUC) in the 300-500 m depth range between 2°S and 2°N. (D'après résumé d'auteur