The sources of sulfate in precipitation: 2. Sensitivities to chemical variables

A convective cloud model used to examine the relative contribution to sulfate in rain of nucleation scavenging (NS) below‐cloud scavenging (BCS) and in cloud production of sulfates (SP) shows that considerable variation may be expected due to change in the amounts of input sulfur species. The case of high input of both SO2 and SO4= bearing aerosol (industrial case) shows SP to be dominant while low inputs yield results ranging from NS and SP being roughly equal to dominance by NS. For the conditions chosen, BCS is low. The sensitivities of the partitioning between these three pathways to changes in SO2, SO4= aerosol, and pH are briefly surveyed.