Wind stress forcing of the Oregon coastal ocean during the 1999 upwelling season

Abstract

The wind stress forcing of the Oregon coastal ocean during June–August 1999 is estimated from a regional mesoscale atmospheric model and from satellite scatterometer observations, supplemented by moored and coastal surface data and by a land‐based wind profiler. Both the mean and variable components of model alongshore wind stress increase by factors of 3–4 from north to south along the Oregon coast. There is evidence of orographic intensification near Cape Blanco, which is supported by previous aircraft and ship observations during August 1995. The systematic southward increase of southward stress will drive enhanced ocean upwelling along the southern Oregon coast and suggests the new hypothesis that systematic variations in local wind stress may contribute to the observed offshore displacement of the coastal upwelling jet in this region. It is inferred from an analysis of the model and surface data that ocean upwelling modifies coastal surface air temperatures by 1–5°C over timescales of 12–24 hours.