ON THE ANNUAL CYCLE OF SATELLITE CHLOROPHYLL OFF CHILE (18°-40°S)

satellite - derived oceanographic parameters were used to explain the coastal and oceanic behavior of the chlorophyll concentration (chl) in chilean waters (18°-40°s, coast- 900 km offshore). chl shows two different regimens of the annual cycle, the closer to the shore one with a austral summer maximum in concordance to the upwelling and wind regimes; and an offshore one with a chl maximum in winter time. the annual cycle is stronger in a thin band (20 km) close to the shore and in the oceanic zone, where it counts for more of the 80% of the variability present. there is a band, which varies with latitude, located between 100-200 km from coast where the annual cycle is not well resolved by the 100 km data bins used in this study. a eof analysis of 9km resolution data was performed and the first mode (29.5% of variance explained) represented clearly the annual cycle and its 6 months out of phase behavior among coastal and oceanic waters the previous idea of a weak annual cycle in northern chile, changes to a strong annual cycle close to the shore with maximum chl in summer, an intermediate zone in which it is no possible to resolve an annual cycle and an outer zone in which the annual cycle has a maximum in the winter months