SULFUR AND HALOGEN CHEMISTRY OF THE STRATOSPHERE AND OF VOLCANIC-ERUPTION PLUMES

The major eruption of Volcan de Fuego caused an enhancement of 1. 6 multiplied by 10**9 kg of SO//4** minus in the stratosphere 6 months after the eruption. Measurable changes in nitric acid vapor and particulate chloride were not observed. Subsequent data suggests that HCl was not injected into the stratosphere. The first simulataneous measurements of halogen and sulfur content of gases and particles in explosive eruption plumes is reported. The average percents of elements in particles were sulfur, 2. 5 plus or minus 2. 1; chlorine, 18 plus or minus 12; and fluorine, 38 plus or minus 29. The average molecular ratio of HCl/SO//2 and HCl/HF were 0. 41 plus or minus 0. 26 and 14 plus or minus 12 in the Guatemalan eruption plumes.