Bobrowski, N

Brusca, L

CALABRESE, Sergio

Giuffrida, G

Liotta, M

Platt, U.

Wittmer, J

Archivio istituzionale della ricerca - Università di Palermo

Geophysical Research AbstractsVol. 16, EGU2014-10771, 2014EGU General Assembly 2014© Author(s) 2014. CC Attribution 3.0 License.New insight into halogen release from experimental studies on BrO/Brratios in volcanic plumesNicole Bobrowski (1), Julian Wittmer (2), Marcello Liotta (3), Sergio Calabrese (4), Giovanni Giuffrida (5),Lorenzo Brusca (5), and Ulrich Platt (1)(1) University of Heidelberg, IUP, Heidelberg, Germany (nbobrows@iup.uni-heidelberg.de), (2) University of Bayreuth,95448 Bayreuth, Germany, (3) Department DiSTABiF, Second University of Naples, Caserta, Italy, (4) Department DiSTeM,University of Palermo, Palermo, Italy, (5) Istituto Nazionale di Geofisica e Vulcanologia, Palermo, ItalySince the discovery of BrO in a volcanic plume (Bobrowski et al. 2003) many measurements have been performedas well as modelling to understand the radical chemistry in volcanic plumes, in particular, the interaction betweenvolcanic gas species, released under strongly reduced conditions, and the oxidizing atmosphere. Besides the goalin atmospheric chemistry to better determine the impact of volcanic emission (e.g. reactive bromine) on the local(and maybe global) scale, volcanologists also have an interest to understand if the BrO/SO2 ratios can be used asa monitoring parameter giving further insides in dynamic processes of volcanoes. However, one of the argumentswhich potentially makes volcanological interpretations difficult is the reactivity of BrO. Therefore it is, of greatimportance to link the measurements of BrO and gaseous hydrogen bromide to the total emission flux of brominein order to estimate the pristine gas composition released from magmas.In particular, trace gas composition of the surrounding atmosphere, the volcanic gas composition and meteorolog-ical parameters can all potentially effect the formation of BrO and might have to be considered. Some of thesefactors potentially also influence near source (crater rim) in-situ measurement. We need to answer the question:Can we correlate BrO measurements to the total bromine outgassing? Only with this knowledge we can relatechanges of the measured gas ratios (BrO/SO2) to the volcanic fluids emitted by the underlying magma and caninterpret data as signals from depth, which provide insight on the degassing of magmatic bodies inside the Earth.Some studies indicate that the BrO/SO2 ratio is close to a temporarily equilibrium already after only few minutesof the gas emission from the vent (e.g. Bobrowski and Giuffrida, 2012). This equilibrium seems to be relativelyindependent from meteorological parameters except for extreme conditions.We here present an empirical approach to answer the above question by discussing BrO formation studies fromfive different volcanoes, Stromboli and Etna (Italy), Masaya (Nicaragua), Gorely (Russia) and Nyiragongo (DRCongo). These volcanoes represent a broad variation in their geological settings, surrounding environment andclimate. They cover subduction related systems and rift volcanism and encompass climate zones from the subarcticto the tropics.For the BrO studies Multi-Axis-Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements havebeen carried out. Active alkaline traps were applied to determine bromine emissions at the crater rim. All measure-ments have been taken simultaneously or within a maximum time distance of a few hours. From these measure-ments we determined that a range of about 5% to 30% of the total bromine is transformed into BrO. We show anddiscuss how the varying BrO-Br partition is related partly to the geological settings, the various meteorologicalconditions and explore further possible influences. We will shortly discuss the current limitations of the commonlyused measurement techniques itself and introduce possible future improvements.

New insight into halogen release from experimental studies on BrO/Br ratios in volcanic plumes

https://iris.unipa.it/retrieve/handle/10447/103771/141406/EGU2014-10771.pdf

New insight into halogen release from experimental studies on BrO/Br ratios in volcanic plumes

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Archivio istituzionale della ricerca - Università di Palermo