Modeling aerosol extinction in a coastal environment

Aerosol particle size distributions were measured during the HEXMAX experiment in the fall of 1986 from Meetpost Noordwijk (MPN), a tower in the North Sea at 9 km from the Dutch coast. Extinction coefficients for wavelengths from 0.55 to 10.6 micrometers were calculated using a Mie routine. The initial analysis showed that straightforward empirical modeling in terms of meteorological parameters did not yield meaningful results. Therefore, the aerosol particle size distributions were modeled in terms of parameters that determine the production, dispersal, and deposition of the aerosol in the coastal marine boundary layer. For an adequate description, the database had to be partitioned into wind-direction sectors based on industrial, rural continental, and predominant marine influences. Based on this empirical aerosol model, the extinction coefficients can be predicted with an accuracy of better than a factor of 1.8. The reliability of the model decreases during frontal passages and periods of rain. The model is validated versus the experimental data and by comparison with the Navy Aerosol Model.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.