Residual circulation in Aysén Fjord, Chile, during spring conditions

Abstract

Time series of currents speed from 3 current meters moored at the mouth of Aysén Fjord, between October and November 1996, were analyze to estimate residual circulation and to relate surface flow to variations in salinity, wind and Aysén River runoff. Residual circulation and salinity at 6 m were determined by events of strong river discharge and relaxing of local wind. Periods of strong outflow and evident drop of salinity at the mouth of the fjord were preceded by a weakening of wind and in some cases were accompanied by an increase of Aysén river discharge. Moreover, the results confirm the 3-layer structure proposed for Aysén fjord, since seaward average currents were observed at 6 and 110 m depth, whereas weak transition average currents were observed at 50 m depth, representing a transition between an intermediate landward flow and the seaward bottom layer.