Marine Air Penetration in Western Oregon: An Observational Study

Abstract

Intense daytime heating in an interior valley and cold upwelled water offshore combine to produce a strong horizontal temperature gradient and the development of a baroclinic field. This leads to an onshore component of the wind in the lower layers with the main features guided by the local topography. Penetration rates of 5 m/s were found. A layer of winds with an easterly component was also found between the low-level westerlies and an upper level westerly current. This easterly current showed signs of being a return flow and was found to have higher small-particle concentrations over the shore than either layer above or below it.