GLOBAL SOURCES AND SINKS OF OCS AND CS2 AND THEIR DISTRIBUTIONS

This study investigates the distribution and magnitudes of the global sources and sinks of OCS and CS2. From an analysis of the correlations between measured emission rates and environmental parameters, the sources of OCS and CS2 are estimated to be 1.23 (0.83-1.71) Tg(OCS) yr-1 and 0.57 (0.34-0.82) Tg(CS2) yr-1, respectively. Our results indicate that 30% of the atmospheric OCS source is derived from the oxidation of CS2, while emissions from the ocean and other natural terrestrial sources contribute 28 % and 24%, respectively. In the case of CS2, the major source is from chemical industrial emissions (58%) while the ocean contributes about 34% to the total CS, source. Our estimate of the OCS and CS2 emission rates suggests that anthropogenic activities contribute approximately 32% to the total OCS source. The major sink for CS2 is oxidation by tropospheric OH, whereas, that for OCS appears to be uptake by vegetation.