Atmos. Chem. Phys., 17, 6477–6492, 2017 www.atmos-chem-phys.net/17/6477/2017/ doi:10.5194/acp-17-6477-2017 © Author(s) 2017. CC Attribution 3.0 License. Surface ozone in the Southern Hemisphere: 20 years of data from a site with a unique setting in El Tololo, Chile Julien G. Anet1,2, Martin Steinbacher1, Laura Gallardo3,4, Patricio A. Velásquez Álvarez5,6, Lukas Emmenegger1, and Brigitte Buchmann1 1Laboratory for Air Pollution/Environmental Technology, Swiss Federal Laboratories for Materials Science and Technology Empa, Duebendorf, Switzerland 2WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland 3Departamento de Geofísica de la Universidad de Chile, Blanco Encalada 2002, piso 4, Santiago, Chile 4Center for Climate and Resilience Research (CR2), Blanco Encalada 2002, Santiago, Chile 5Dirección Meteorológica de Chile, Av. Portales 3450, Estación Central, Santiago, Chile 6Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland Correspondence to: Julien G. Anet (
[email protected]) and Martin Steinbacher (
[email protected]) Received: 12 July 2016 – Discussion started: 7 October 2016 Revised: 24 March 2017 – Accepted: 25 April 2017 – Published: 31 May 2017 Abstract. The knowledge of surface ozone mole fractions located over the Pacific Ocean. Therefore, due to the neg- and their global distribution is of utmost importance due to ligible influence of local processes, the ozone record also al- the impact of ozone on human health and ecosystems and the lows studying the influence of El Niño and La Niña episodes central role of ozone in controlling the oxidation capacity of on background ozone levels in South America.