Sources and Isotopic Composition of Atmospheric Sulfur.

In nonindustrial areas the prime source of SO(--)(4) in rain and snow is atmospherically oxidized H(2)S that is produced predominately along coastal belts by anaerobic bacteria. The delta S(34) analyses of atmospheric SO(--)(4) vary from +3.2 to +15.6 per mil in contrast to +20.7 per mil for sea water SO(--)(4). Contrary to previous studies based on Cl(-)/SO(--)(4) ratios, sea spray SO(--)(4) is a minor source.