Determinations of Sulfur Dioxide in the Northwest Pacific Atmosphere on ACE-Asia

Sulfur dioxide was determined on ACE-Asia using isotope dilution atmospheric pressure ionization mass spectrometry. We achieved a lower limit of detection of at least 5 pptv with an integration time of 1 second. Sulfur dioxide was sampled at a rate of 2 hertz that enabled us to observe variations in sulfur dioxide that was not possible with slower instrumentation. We observed sulfur dioxide concentrations from 10 pptv to 40 ppbv. Extensive layering was observed which was related to complicated horizontal and vertical transport especially in the vicinity of cloud. On several occasions we observed the interaction of sulfur dioxide with Gobi desert dust.