Constructing a Miniaturized Chemiluminescence Ozone Monitor for Drone-Based Measurements in Volcanic Plumes: A Way to Resolve the Volcanic Ozone Enigma

Volcanic plumes contain reactive halogen species, especially bromine monoxide (BrO), which catalyzes ozone (O3) destruction. Therefore, local O3 depletion is commonly assumed inside volcanic plumes and has also been measured to varying degrees at different volcanoes. However, a calculation comparing atmospheric mixing with the rate of O3 destruction inside the plume suggests no significant reactive halogen catalyzed O3 loss (1% or less) in the plume. So far, O3 and its distribution in volcanic plumes have only been insufficiently determined since commonly used ultraviolet (UV) absorption O3 monitors show interference with sulfur dioxide (SO2), an abundant volcanic gas. This issue can be overcome by using a chemiluminescence (CL) O3 monitor, which has no known interference from trace gases abundant in volcanic plumes. However, field measurements with former CL O3 monitors are challenging, as they are heavy and bulky. Here we report on a lightweight version of the instrument (1.5 kg, shoebox size), which can be mounted onto a drone. In particular, the design, construction, and characterization are presented in this thesis. Measurements in the field were performed, including ambient measurements in Heidelberg and drone measurements during which a vertical O3 profile was measured. The main focus of the measurements is the drone-based O3 measurements in the plume of Etna. With the simultaneous SO2 measurement, an anti-correlation in the data can be observed, suggesting an O3 depletion of up to ~60% in the volcanic plume of Etna. This raises the question of which process leads to this observed O3 depletion.

Level thesis:degree_level

master

Grantor dc:publisher

Universität Heidelberg

Year

2023

Author dc:creator

• Rüth, Maja

Contributors dc:contributor

• Platt, Ulrich

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/34520

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:34520