Author/Authors :
Valle–Levinson، نويسنده , , A. and Schneider، نويسنده , , W. and Sobarzo، نويسنده , , M. and Bello، نويسنده , , M. and Bravo، نويسنده , , L. and Castillo، نويسنده , , M. and Duarte، نويسنده , , L. and Fuenzalida، نويسنده , , Adam R. and Gallegos، نويسنده , , J.M. and Garcés–Vargas، نويسنده , , J. and Gonz?lez، نويسنده , , J. and Gutiérrez، نويسنده , , D. and Molinet، نويسنده , , C. and Navarro، نويسنده , , M.S. and Pierini، نويسنده ,
Abstract :
Hydrographic and underway water velocity profiles were measured at the entrance to Concepción Bay, an equatorward facing embayment in central Chile, in order to illustrate the wind-induced exchange flow. Observations took place over a 25-h period (5–6 January 2002) during the austral summer, which is characterized by upwelling winds in the region. One portion of the observational transect was directly influenced by the wind and the other was protected from such influence by an island. The portion of the transect influenced by wind showed a surface layer, delimited by a pycnocline, moving downwind owing to the direct action of wind stress. This surface transport should have caused an onshore decrease of surface elevation that would drive upwind flow below the surface layer. The portion of the transect protected by the island was influenced by its wake and perhaps forced by a semidiurnal tide. This study is one of the few observational examples of wind-induced flow that documents the wind-induced exchange pattern under weak internal friction (low Ekman number). This pattern consists of downwind flow in an upper layer delimited by the pycnocline and upwind flow below.
