Using radon-222 to distinguish between vertical transport processes at Jungfraujoch
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Date
2015-04-14
Journal Title
Journal ISSN
Volume Title
Publisher
European Geosciences Union
Abstract
Trace gases measured at Jungfrajoch, a key baseline monitoring station in the Swiss Alps, are tranported from the surface to the alpine ridge by several different processes. On clear days with weak synoptic forcing, thermally-driven upslope mountain winds (anabatic winds) are prevalent. Using hourly radon–222 observations, which are often used to identify air of terrestrial origin, we used the shape of the diurnal cycle to sort days according to the strength of anabatic winds. Radon is ideal as an airmass tracer because it is emitted from soil at a relatively constant rate, it is chemically inert, and decays with a half-lifen of 3.8 days. Because of its short half-life, radon concentrations are much lower in the free troposphere than in boundary-layer air over land. For comparable radon concentrations, anabatic wind days at Jungfraujoch are different from non-anabatic days in terms of the average wind speed, humidity, air temperature anomalies, and trace species. As a consequence, future studies could be devised which focus on a subset of days, e.g. by excluding anabatic days, with the intention of choosing a set of days which can be more accurately simulated by a transport model. © Author(s) 2014.
Description
Keywords
Radon 222, Gases, Switzerland, Alps, Wind, Troposphere, Boundary layers, Humidity
Citation
Griffiths, A., Chambers, S., Conen, F., Weingartner, E., Zimmermann, L., Williams, A., & Steinbacher, M. (2015). Using radon-222 to distinguish between vertical transport processes at Jungfraujoch. Paper presented at the European Geosciences Union General Assembly 2015, 12-17 April 2015, Vienna, Austria. Retrieved from https://meetingorganizer.copernicus.org/egu2015/meetingprogramme