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UP: Fachverband Umweltphysik
UP 4: Poster: Atmosphäre und Klima
UP 4.3: Poster
Tuesday, March 11, 2008, 16:30–19:00, Poster B1
Halogen oxide measurements at Masaya volcano in Nicaragua using Differential Optical Absorption Spectroscopy — •Christoph Kern1, Holger Sihler1, Leif Vogel1, Claudia Rivera2, and Ulrich Platt1 — 1Institut für Umweltphysik, Universität Heidelberg, Heidelberg, Deutschland — 2Chalmers University of Technology, Department of Radio and Space Science, Gothenburg, Sweden
Sulphur dioxide (SO2) and halogen oxide emissions were measured at Masaya Volcano in Nicaragua in April 2007 using Differential Optical Absorption Spectroscopy (DOAS). Next to passive DOAS measurements using scattered sunlight, an active long-path DOAS system was operated for several days with the light beam crossing the crater of the volcano. These measurements for the first time give an insight into the night-time halogen chemistry occurring at volcanoes. While the passive DOAS instruments measured sulphur dioxide (SO2) and bromine monoxide (BrO) in various viewing geometries and distances from the crater during daytime, the active instrument additionally allowed a quantification of chlorine monoxide (ClO) and chlorine dioxide (OClO), as well as being able to measure round-the-clock. The results of the field measurements are presented and their implications for halogen chemistry at volcanoes are discussed.