On the influence of topography in the induction of coastal upwelling along the Chilean coast

The contribution of the winds and the topography in the induction of upwelling along the Chilean coastal zone is calculated. The topographic-induced upwelling is estimated, taking into account the effect of the meridional changes of the coastline orientation. The wind-induced upwelling was calculated for the austral summer using NSCAT scatterometer data, resulting a total amount of 2.1x10(6) m(3)s(-1) of water transported offshore for the whole Chilean upwelling zone. It is shown that the topographic effect dominates the wind-induced upwelling in several parts of the Chilean coast, particularly at 23 degreesS (Antofagasta), 25.5 degreesS, 30 degreesS (Coquimbo), 33 degreesS (Valparaiso) and 37 degreesS (Concepcion). Antofagasta, Coquimbo, Valparaiso and Concepcion are well known zones of intense upwelling. The results show that the topography plays a key role in the upwelling of the Chilean coast, specially in its northern part.