Determination of the effects of coastal-trapped waves on SST, phytoplankton pigment concentration and synoptic scale winds

Determination of the effects of coastal-trapped waves on sea surface
temperature, phytoplankton pigment concentration and synoptic scale
winds in the near coastal zone.

Along the west coast of the Americas, sea levels and alongshore
currents show large oscillations at intraseasonal periods (~30-80
days). Observations and theory have shown that many of these
fluctuations are caused by coastal trapped waves, originated by
equatorial Kelvin waves striking the west coast of Souther America.

Current and temperature records and CTD casts over the continental
slope in northern and central Chile exhibit common, intraseasonal
fluctuations of at least 10-15 cm/s near 220m depth and vertical
isotherm displacements of at least serveral tens of meters near the
thermocline. These oscillations are quite large perturbations in the
coastal ocean and appear to be strongly modulating upwelling,
influencing the nutrient concentration and the sea surface temperature
variability near the coast. In central Chile, the alongshore wind
stress also shows intra-seasonal flucations. They are approximately
in phase with atmospheric perturbations that occur in the central
equatorial Pacific. These oscillations may generate intra-seasonal
waves in the ocean that may be superimposed on the remotely generated
Coastal trapped waves.