1Australian Nuclear Science and Technology Organisation, New South Wales, Australia
2Environmental Geosciences, Department of Geosciences, University of Basel, Basel, Switzerland
3Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
4Swiss Federal Laboratories for Materials Science and Technology (Empa), Dübendorf, Switzerland
*now at: Institute for Aerosol and Sensor Technology, University of Applied Sciences, 5210 Windisch, Switzerland
Received: 05 May 2014 – Discussion started: 04 Jul 2014
Abstract. Atmospheric composition measurements at Jungfraujoch are affected intermittently by boundary-layer air which is brought to the station by processes including thermally driven (anabatic) mountain winds. Using observations of radon-222, and a new objective analysis method, we quantify the land-surface influence at Jungfraujoch hour by hour and detect the presence of anabatic winds on a daily basis. During 2010–2011, anabatic winds occurred on 40% of days, but only from April to September. Anabatic wind days were associated with warmer air temperatures over a large fraction of Europe and with a shift in air-mass properties, even when comparing days with a similar mean radon concentration. Excluding days with anabatic winds, however, did not lead to a better definition of the unperturbed aerosol background than a definition based on radon alone. This implies that a radon threshold reliably excludes local influences from both anabatic and non-anabatic vertical-transport processes.
Revised: 30 Sep 2014 – Accepted: 17 Oct 2014 – Published: 08 Dec 2014
Griffiths, A. D., Conen, F., Weingartner, E., Zimmermann, L., Chambers, S. D., Williams, A. G., and Steinbacher, M.: Surface-to-mountaintop transport characterised by radon observations at the Jungfraujoch, Atmos. Chem. Phys., 14, 12763-12779, doi:10.5194/acp-14-12763-2014, 2014.