Atmos. Chem. Phys., 18, 6567–6584, 2018 https://doi.org/10.5194/acp-18-6567-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. Stratospheric ozone measurements at Arosa (Switzerland): history and scientific relevance Johannes Staehelin1, Pierre Viatte2, Rene Stübi2, Fiona Tummon1, and Thomas Peter1 1Institute for Atmospheric and Climate Science, ETHZ, Zürich, Switzerland 2Federal Office of Meteorology and Climatology MeteoSwiss, Payerne, Switzerland Correspondence: Johannes Staehelin (
[email protected]) Received: 20 November 2017 – Discussion started: 29 November 2017 Revised: 15 March 2018 – Accepted: 22 March 2018 – Published: 8 May 2018 Abstract. In 1926 stratospheric ozone measurements began identifying potentially unexpected stratospheric responses to at the Light Climatic Observatory (LKO) in Arosa (Switzer- climate change, support the continued need to document land), marking the beginning of the world’s longest series stratospheric ozone changes. This is particularly valuable at of total (or column) ozone measurements. They were driven the Arosa site, due to the unique length of the observational by the recognition that atmospheric ozone is important for record. This paper presents the evolution of the ozone layer, human health, as well as by scientific curiosity about what the history of international ozone research, and discusses the was, at the time, an ill characterised atmospheric trace gas. justification for the measurements in the past, present and From around the mid-1950s to the beginning of the 1970s into future. studies of high atmosphere circulation patterns that could improve weather forecasting was justification for studying stratospheric ozone. In the mid-1970s, a paradigm shift oc- curred when it became clear that the damaging effects of 1 Introduction anthropogenic ozone-depleting substances (ODSs), such as long-lived chlorofluorocarbons, needed to be documented.