THE IMPACTS OF SEA-SALT AND NSS-SULFATE AEROSOLS ON CLOUD MICROPROPERTIES

Impacts of nss-sulfate and sea-salt on marine clouds microphysical properties are investigated using a mutil-component size-resolving aerosol model. Numerical results show that the vertical distribution of liquid water content remains almost constant as sea salts number and updrafts increase. The effective radius decreases as cloud drops number increases. The number of cloud drops is dominated by nss-sulfate. Sea-salt plays a critical role in cloud microphysical processes. Due to its large radius sea-salt particles are activated into cloud drops in the initial cloud development. Sea-salt activation decreases supersaturation by consuming water vapor and suppresses nss-sulfate activation. Sea salts can enhance cloud drops number concentration under the case of large updrafts and decrease under the case of low updrafts. Nss-sulfate indirect forcing may be overestimated in some conditions (such as updraft is low) because of the presence of sea-salt particles.