Estimates of the fluxes of NO, SO₂, H₂S, CS₂ and OCS from Mt. St. Helens deduced from in situ plume concentration measurements

Abstract

Measurements of the concentrations of NO, SO 2 , H 2 S, CS 2 , and OCS were made in the Mt. St. Helens plume September 22, 1980. In this study the NO, SO 2 and H 2 S concentrations were in the range 20‐314 pptv, 0‐438 ppbv and 0‐54 ppbv respectively. The concentrations of CS 2 and OCS were below our lower limit of detection of 10 ppbv. Ratios of the concentrations of NO and SO 2 and H 2 S and SO 2 were found to be 1.3 × 10 −3 and 0.13 respectively. Fluxes of 65 and 1.1 tons per day were estimated for H 2 S and NO respectively. The fluxes of CS 2 and OCS were found to be less than 20 tons per day.