SPECIFICATION OF THE WIND DISTRIBUTION IN THE MARINE BOUNDARY LAYER FOR WAVE FORECASTING

Abstract : The operational application of sophisticated spectral ocean wave specification models to wave forecasting requires that an adequate meteorological input to these models consist of a specification of the wind distribution in the marine surface boundary layer. This study demonstrates how this requirement can be satisfied in a computerized objective format from routinely available meteorological data and prognostic fields. Wave generation theory is employed to develop a quantitative formulation for the effects of atmospheric stability upon the development of the wave spectrum. In terms of this stability dependent spectral growth formulation, the effects of stability on wave generation are found to be significant and compare well with observational studies of the dependence of wave height and white-cap production on air-sea temperature difference. A simple model of the non-neutral, baroclinic planetary boundary layer over a sea surface described in terms of an internally prescribed roughness parameter is derived. The model is shown to provide a suitable framework for the diagnosis of the marine surface boundary layer wind distribution from prognostic fields of sea level pressure, air temperature and sea surface temperature.