Resumen de Featuring enso 1997-2000 in central Chile
Mónica Bello, Manuel Castillo, Jenny Maturana, Claudia Valenzuela, M Angela Barbieri
Using satellite images of the area between 32-36°S and 71-75°W, from October 1997 to September 1999, temporal and spatial variability of sea surface temperature (SST) was analyzed. During this period of time, one of the most intense episode of the last century of the warm phase (El Niño) and the beginning of the cold phase (La Niña) of the ENSO cycle were registered, allowing to identify differences in the thermal surface structure. During the warm phase, cold water isotherms in the coastal region (upwelling) warmer than usual were presented, and temperature gradients offshore were smaller than in the cold phase. Several reports suggest that a large part of the Eastern Ocean Pacific Boundary variability (particularly at low frequencies) has equatorial origin. This research shows that part of the observed fluctuations in sea level at Callao, are due to intraseasonal oscillations likely modulated by perturbations of equatorial origin propagating as coastal trapped waves at the eastern boundary of the Pacific Ocean, having a signature in the currents off Valparaiso as a poleward flow, whose core exhibits higher salinity and low oxygen located at 180 m depth. On the other hand, geostrophic currents off Valparaiso consists of alongshore currents and countercurrents, with increasing speeds at fall
