Application of a mixed-layer model to aerosols in the marine boundary layer

Abstract

A mixed-layer model for the concentration and evolution of marine aerosols is presented. Theambient aerosol spectrum is divided into continental and sea-salt components and transformedto a reference saturation ratio. The temporal evolution of the aerosol spectrum is predicted fromrate equations that require specification of the mixed-layer depth. particle production at thesurface, and particle entrainment into the mixed layer from aloft. The model was tested against amarine data set obtained off Southern California during the CEWCOM-78 experiment. The testwas carried out with two different methods of obtaining the relevant meteorological and aerosolparameters: (i) actual measurements and (ii) dynamic boundary layer model prediction andparameterization. In the first case. the model reproduced the aerosol data within a factor of 1.5.while in the second case, the uncertainty factor was 2.0. In either case. the model only modestlyout-performs a much simpler model, which uses only local specification of the wind speed andhumidity. DOI: 10.1111/j.1600-0889.1984.tb00242.x