LAUSR

Information about sea spray aerosol particle transport and their vertical distribution in the marine atmospheric boundary layer (MABL) is important in marine meteorological forecasting and geobiochemical models. However, due to difficulties in field observations, values of aerosol concentration are often limited to point measurements, and obtaining the size-resolved concentration profiles is quite challenging. Hence, numerical and analytical studies are vital in modeling the transport of aerosols in the atmospheric boundary layer and beyond. Due to their coarse resolution, most mesoscale and global aerosol models do not accurately resolve the sea spray and aerosol concentrations in the MABL, especially in the surface layer. The objective of the present study is to develop a relatively simple, one-dimensional analytical model to calculate concentration profiles of aerosols in the MABL. In this study, a new analytical model relating surface flux to vertical concentration profile in the MABL is proposed. The model accounts for the different atmospheric stability and particle settling velocity, thus providing size-resolved vertical profiles of aerosol concentration. The equations developed here extend the surface layer similarity models to the mixed layer. Model results are compared to aerosol concentration profiles emitted from a surface source obtained from large eddy simulations, for both neutral and unstable atmospheric stability and for particle sizes ranging from 1 to 30 μm. Though the model is developed for sea spray aerosols, it can be used to calculate vertical concentration profiles for other types of settling particles, including dust and sand particles in the atmospheric boundary layer.