Vertical profiles of marine aerosol size distribution and concentration in the marine boundary layer over surf zones depend strongly on wind speed, direction and duration as well as the sea bottom profile. The measurements in the present study were carried out in various seasons of the year with all these factors being taken into consideration. The data with respect to offshore winds were neglected in the calculations, since in such cases the major aerosol contribution was from terrigenous and anthropogenic particles. It was confirmed that in the range of wind speeds from 1 m s−1 to 12 m s−1 there were measurable differences in the concentrations, particularly in the size distribution of marine aerosol particles at two stations differing with respect to their sea bottom profiles.
The paper presents the findings of experiments to determine marine aerosol emission from the coastal zone. A relation between aerosol flux and wave energy dissipation was found. The emission fluxes calculated for the distribution of aerosol concentration are proportional to the dissipation of wave energy to the power of 3/4. The calculations were carried out using the experimental data obtained during the TABEX and BAEX experiments.
Aerosol samples were collected in May 1997 at a routine off-shore measurement station in the Gdańsk Deep region and at Hel, the latter being a coastal station situated at the tip of the Hel Peninsula. Concentrations of NO− 3 , Cl−, Na+, Mg2+, K+ and Ca2+ were measured simultaneously at both stations. The sea influences the chemical composition of aerosols in the coastal zone of the Gulf of Gdańsk regardless of season, time of day or direction of advection. Sodium chloride was always present in aerosols in the form of large particles originating from seawater. Besides the marine chloride and nitrate, additional amounts of these ions could have been of terrigenous origin. Sodium and chloride concentrations were dominant in the total mass of aerosols at both stations; however, these concentrations were three times higher at the marine station. Similarly, the concentrations of ions originating from seawater, like magnesium and calcium, were, on average, three times higher at the marine station. The chemical composition of aerosols and air over the Gulf of Gdańsk was modified through the evaporation of chloride from the marine salt particles in reactions with gaseous nitric and sulphuric acids. A certain deficit of chloride versus sodium ions was noted. At the marine station the Cl−/Na+ ratio reached 0.89 ± 0.2, on average, while over the land station it was 0.93 ± 0.25, i.e. lower than the seawater standard.