COMPETITION BETWEEN SEA-SALT AND SULFATE PARTICLES AS CLOUD CONDENSATION NUCLEI

The influence of yea salt on the cloud droplet activation of sulfate p articles is investigated using a size-resolving model of the aerosol a ctivation process. The authors found that the total number concentrati on of activated cloud droplets increases with increasing sea salt conc entration if the sulfate number concentrations are relatively low and updrafts are strong, but it decreases with higher sea salt if sulfate number concentrations are high and cloud updrafts are weak. The increa se is due to the activation of accumulation mode sea salt particles. w hile the decrease is due to the reduction in maximum cloud supersatura tion due to competition with coarse mode sea salt particles. These con clusions are insensitive to the sulfate size distribution and surface wind speed.