0000000000699204
AUTHOR
Tjarda Roberts
showing 5 related works from this author
The primary volcanic aerosol emission from Mt Etna: Size-resolved particles with SO2 and role in plume reactive halogen chemistry
2018
International audience; Volcanoes are an important source of aerosols to the troposphere. Within minutes after emission, volcanic plume aerosol catalyses conversion of co-emitted HBr, HCl into highly reactive halogens (e.g. BrO, OClO) through chemical cycles that cause substantial ozone depletion in the dispersing downwind plume.This study quantifies the sub-to-supramicron primary volcanic aerosol emission (0.2-5 μm diameter) and its role in this process. An in-situ ground-based study at Mt Etna (Italy) during passive degassing co-deployed an optical particle counter and Multi-Gas SO2 sensors at high time resolution (0.1 Hz) enabling to characterize the aerosol number, size-distribution and…
Validation of a novel Multi-Gas sensor for volcanic HCl alongside H2S and SO2 at Mt. Etna
2017
Erratum to: Bull Volcanol (2017) 79: 36DOI 10.1007/s00445-017-1114-zDuring the steps of corrections, the publisher inadvertently changed the author affiliations so that they were no longer correct. The correct information is given below. The publisher regrets this mistake.; International audience; Volcanic gas emission measurements inform predictions of hazard and atmospheric impacts. For these measurements, Multi-Gas sensors provide low-cost in situ monitoring of gas composition but to date have lacked the ability to detect halogens. Here, two Multi-Gas instruments characterized passive outgassing emissions from Mt. Etna’s (Italy) three summit craters, Voragine (VOR), North-east Crater (NE…
Towards a representation of halogen chemistry within volcanic plumes in a chemistry transport model
2014
Volcanoes are a known source of halogens to the atmosphere. HBr volcanic emissions lead rapidly to the formation of BrO within volcanic plumes as shown by recent work based on observations and models. BrO, having a longer residence time in the atmosphere than HBr, is expected to have a significant impact on tropospheric chemistry, at least at the local and regional scales. The objective of this paper is to prepare a framework that will allow 3-D modelling of volcanic halogen emissions in order to determine their fate within the volcanic plume and then in the atmosphere at the regional and global scales. This work is based on a 1-D configuration of the chemistry transport model MOCAGE whose …
Rapid chemical evolution of tropospheric volcanic emissions from Redoubt Volcano, Alaska, based on observations of ozone and halogen-containing gases
2013
Abstract We report results from an observational and modeling study of reactive chemistry in the tropospheric plume emitted by Redoubt Volcano, Alaska. Our measurements include the first observations of Br and I degassing from an Alaskan volcano, the first study of O 3 evolution in a volcanic plume, as well as the first detection of BrO in the plume of a passively degassing Alaskan volcano. This study also represents the first detailed spatially-resolved comparison of measured and modeled O 3 depletion in a volcanic plume. The composition of the plume was measured on June 20, 2010 using base-treated filter packs (for F, Cl, Br, I, and S) at the crater rim and by an instrumented fixed-wing a…
In-situ characterisation of aerosol and gases (SO 2 , HCl, ozone) in Mt Etna volcano plume
2015
International audience; We present findings from a measurement campaign that deployed a range of in-situ real-time atmospheric measurement techniques to characterise aerosols and gases in Mt Etna plume in October 2013. The LOAC (Light Optical Aerosol Counter) instrument for size-resolved particle measurements was deployed alongside two Multi-Gas instruments (measuring SO 2 , H2S, HCl, CO 2) and an ozone sensor. Measurements were performed at the summit craters (in cloudy-and non-cloudy conditions) and in grounding downwind plume on the volcano flank. These high frequency measurements (acid gases: 1 to 0.1 Hz, aerosol: 0.1 Hz) provide a detailed in-situ dataset for time-resolved plume charac…