Photochemical production of carbonyl sulfide in precipitation

Abstract

Precipitation samples (rain and snow) from 10 provinces in China were collected during the winter season. The concentration of initial dissolved carbonyl sulfide (COS) and its photochemical production rates by natural sunlight were measured. All investigated precipitation samples were found to be supersaturated with COS, and the initial dissolved COS concentrations were in the range from 17.7 to 48.2 ng L-1. The COS saturation ratios (SR) for the investigated samples were in the range from 15.8 to 60.4. The COS photochemical production rates depended strongly on sunlight intensity and were independent of microbial activity as well as dissolved O2. The amount of COS produced photochemically by sunlight irradiation for 14 to 50 days was ∼1-2 orders of magnitude greater than that of initial dissolved COS. Copyright 2004 by the American Geophysical Union.