The use of atmospheric cosmogenic 35 S and 7 Be in determining depositional fluxes of SO 2

We explore the use of two cosmogenically produced nuclides in the atmosphere, 35 S (half‐life = 87 days) and 7 Be (half‐life = 53 days), as tracers of gaseous SO 2 and aerosol SO 4 and Be removal processes to the Earth's surface. Based on 35 S and 7 Be wet precipitation fluxes and 35 SO 2 , 35 SO 4 and 7 Be concentrations in air samples in the planetary boundary layer at New Haven, Connecticut (USA) we determine coefficients for incloud scavenging of 35 SO 2 , oxidation of 35 SO 2 to 35 SO 4 in both the planetary boundary layer and the free troposphere, and dry deposition. In addition, the distributions of 35 SO 2 , 35 SO 4 and 7 Be between the planetary boundary layer and the free troposphere are determined as well as the air exchange coefficient between the two reservoirs. Application to stable S yields a dry deposition flux to total flux ratio of about 0.20 for August, 1990.