Impact of a moderate volcanic eruption on chemistry in the lower stratosphere: balloon-borne observations and model calculations

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Berthet, Gwenaël, Jégou, Fabrice, Catoire, Valéry, Krysztofiak, Gisèle, Renard, Jean-Baptiste, Bourassa, Adam E., Degenstein, Doug A., Brogniez, Colette, Dorf, Marcel, Kreycy, Sebastian, Pfeilsticker, Klaus, Werner, Bodo, Lefèvre, Franck, Roberts, Tjarda J., Lurton, Thibaut, Vignelles, Damien, Bègue, Nelson, Bourgeois, Quentin, Daugeron, Daniel, Chartier, Michel, Robert, C, Gaubicher, Bertrand, Guimbaud, Christophe
• Other Authors: Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales Paris (CNES), Institute of Space and Atmospheric Studies Saskatoon (ISAS), Department of Physics and Engineering Physics Saskatoon, University of Saskatchewan Saskatoon, Canada (U of S)-University of Saskatchewan Saskatoon, Canada (U of S), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut für Umweltphysik Heidelberg, Universität Heidelberg Heidelberg = Heidelberg University, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Agence Nationale de la Recherche (ANR), European Union, ANR-08-BLAN-0300,StraPolEté,Dynamique, aérosols et brome dans la stratosphère polaire en été(2008), ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010), European Project: 226365,EC:FP7:ENV,FP7-ENV-2008-1,RECONCILE(2009), European Project: 226224,EC:FP7:ENV,FP7-ENV-2008-1,SHIVA(2009)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology; Kiruna; Esrange; Arctic; Northern Sweden
• Online Access: https://insu.hal.science/insu-01367008; https://insu.hal.science/insu-01367008/document; https://insu.hal.science/insu-01367008/file/acp-17-2229-2017.pdf; https://doi.org/10.5194/acp-17-2229-2017

International audience The major volcanic eruption of Mount Pinatubo in 1991 has been shown to have significant effects on stratospheric chemistry and ozone depletion even at mid-latitudes. Since then, only "moderate" but recurrent volcanic eruptions have modulated the stratospheric aerosol loading such as the eruption of the mid-latitude Sarychev volcano which injected 0.9 Tg of sulfur dioxide (about 20 times less than Pinatubo) in June 2009. In this study, we investigate the chemical impacts of the enhanced liquid sulfate aerosol loading resulting from this moderate eruption using data from a balloon campaign conducted in northern Sweden (Kiruna-Esrange, 67.5° N, 21.0° E) in August-September 2009. Balloon-borne observations of NO 2, HNO 3 and BrO from infrared and UV-visible spectrometers are compared with the outputs of a three-dimensional (3-D) Chemistry-Transport Model (CTM). It is shown that differences between observations and model outputs are not due to transport calculation issues but rather reflect the chemical impact of the volcanic plume below 19 km in altitude. Good measurement-model agreement is obtained when the CTM is driven by volcanic aerosol loadings derived from in situ or space-borne data. As a result of enhanced N 2 O 5 hydrolysis in the Sarychev volcanic aerosol conditions, the model calculates reductions of ~ 45 % and increases of ~ 11 % in NO 2 and HNO 3 amounts respectively over the summer 2009 period. The decrease in NO x abundances is limited due to the expected saturation effect for high aerosol loadings. The links between the various chemical catalytic cycles involving chlorine, bromine, nitrogen and HO x compounds in the lower stratosphere are discussed. The increased BrO amounts (~ 22 %) compare rather well with the balloon-borne observations when volcanic aerosol levels are accounted for in the CTM and appear to be mainly controlled by the coupling with nitrogen chemistry rather than by enhanced BrONO 2 hydrolysis. Simulated effects of the Sarychev eruption on chlorine ...