Filter Measurements of Stratospheric Sulfate and Chloride in the Eruption Plume of Mount St. Helens

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Science  20 Feb 1981:
Vol. 211, Issue 4484, pp. 826-827
DOI: 10.1126/science.211.4484.826


Five flights of the U-2 aircraft with a filter sampler aboard were flown in the Mount St. Helens debris from 19 May to 17 June 1980. Sulfate concentrations as large as 216 times the expected background were observed. The enhancements of acid chloride vapor were considerably smaller, suggesting an insignificant increase of background values of hydrogen chloride once the plume is well mixed throughout the lower stratosphere.