ACID DEPOSITION DURING 2 CONTRASTING FRONTAL RAINFALL EVENTS

Analysis of the chemical composition of rain at high temporal resoluti on provides additional information on wet deposition processes. High r esolution data was obtained using a microprocessor-based acid rain mon itor at two sites in SW Scotland and SE England. Meteorological detail s of the transport and wet deposition processes during two frontal rai n events were examined and related to rainfall composition. Rapid depl etions of ion concentrations during heavy rainfall in the first event were interpreted using a rainfall scavenging model. The sub-event data for the second event showed the influence of frontal discontinuities. Increasing ionic concentrations during this second event were attribu ted both to the change in air mass, and to diminished upwind precipita tion scavenging.