Estimation of the along-shore flow in Peru-Chile Undercurrent

The Humboldt Current system, bound by the steep continental slope and narrow shelf of western South America, is one of the four major Eastern Ocean Boundary Current systems of the world. Equator-ward winds predominate during most of the year north of about 33S, driving a large coastal upwelling system that extends from central Chile to northern Peru.

The large scale mean circulation and water properties distribution is consistent, in general, with a Sverdrup balance, while the physical coastal environment is dominated by the coastal upwelling, the persistent subsurface pole-ward Peru-Chile Undercurrent (PCU) and inter-annual variability related to El Nino-Southern oscillation (ENSO) and intra-seasonal, remotely-forced coastal-trapped waves. During the last 3 years (1997-2000), current measurements from two sites near 30S, started in 1991, continued with the support of the FONDAP-Humboldt programme.