Halogen activation in volcanic plumes: Studies at Mt Etna (Italy) 2022 and 2023
- 1Johannes Gutenberg-University, Department of Chemistry, AK Hoffmann, Mainz, Germany (bageil@uni-mainz.de)
- 2Institute of Environmental Physics, Ruprecht-Karls-University, Germany
- 3Istituto Nazionale di Geofisica e Vulcanologica - Osservatorio Etneo, Italy
- 4Department of Atmospheric and Oceanic Sciences, University of California, LA, USA
- 5LPC2E, CNRS/Universite d´Orleans, Orleans, France
- 6Institute for Atmospheric Physics, Johannes Gutenberg-Universität, Mainz, Germany
Halogens in volcanic plumes are important for both volcanic and environmental research. For example, changes in the composition of the volcanic plume can be an indication of changes in the activity of the volcano. Volcanic emissions consist mainly of emitted H2O, CO2 and SO2 and are rapidly mixed with surrounding background atmosphere. Additionally, HF, HCl and HBr are also significant constituents of volcanic emissions.
The halogens are of particular interest for atmospheric chemistry. They are oxidized by mixing with the atmosphere. In this context, BrO should be mentioned as it is one of the oxidation products and like SO2, can be measured spectroscopically using remote sensing technique and therefore making it nearly ideal for surveillance of volcanoes. However only, if the oxidation process is understood, the composition of the volcanic plume at the emission site can be traced and thus possibly the changes in volcanic activity can be understood.
Furthermore, these results are essential for the improvement of the atmospheric impact of volcanic halogens.
Currently, several methods are used to detect the various halogen compounds. Remote sensing methods exist for only a few (in general BrO, OClO, HCl, HF). We use in-situ sampling methods such as cis-Stilbene coated syringe filter and aqueous alkaline traps to collect reactive and total halogen species, respectively.
In this presentation, we will show quantitative results of samples taken in July 2022, June 2023 and in August 2023 for Cl2, Br2, BrCl, total bromine and sulfur from measurements of the Bocca Nuova and South East crater plume, Mt. Etna, Italy using UAV based in situ measurements in various distances to those emission sources. The results confirm the increase of reactive bromine and show for the first time the differentiation into Cl2, Br2, BrCl and total bromine and sulfur. Also BrO/SO2 values analyzed from DOAS measurements taken further downwind during the campaign will be presented.
How to cite: Geil, B., Bobrowski, N., Karbach, N., Kuhn, J., Nies, A., Roberts, T., Hoor, P., and Hoffmann, T.: Halogen activation in volcanic plumes: Studies at Mt Etna (Italy) 2022 and 2023, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14976, https://doi.org/10.5194/egusphere-egu24-14976, 2024.
