2004 Volume 39 Issue 2 Pages 63-76
The influences of fog generation/evaporation on the properties of aerosol particles were investigated through the analyses of gas, aerosol particles and droplets off the coast of East Hokkaido in Japan during the foggy season (April and July, 2001) and non-foggy season (October, 2000 and January, 2001). Case study of a single fog event indicates that 1) SO2, NH3 and HNO3 gas were dissolved in droplets above 2μm in diameter during a fog event and 2) Na+ concentration in fine particles (<2μm) increased during evaporation stage suggesting droplet splashing.
Particle fractions (PF) and fine particle fractions (FPF) in all seasons were analyzed to evaluate the influences of fog on aerosol particles. In foggy season, the average PF of SO42-and NH4+were higher than those of non-foggy season indicating that the dissolution of gas under foggy generation. On the other hand the average FPF of Na+ in foggy season were 3 times as large as non-foggy season suggesting that droplets splash during the evaporation of fog droplets. From these results it is concluded that fog cycles play roles in seasonal variation of aerosol chemistry in this area.
