Author Affiliations

Alkiviadis F. Bais,¹ Stylianos Kazadzis,¹ Katerina Garane,¹ Natalia Kouremeti,¹ Julian Gröbner,² Mario Blumthaler,³ Gunther Seckmeyer,⁴ Ann R. Webb,⁵ Tapani Koskela,⁶ Peter Görts,⁷ and Josef Schreder⁸

¹Alkiviadis F. Bais, Stylianos Kazadzis, Katerina Garane, and Natalia Kouremeti are with the Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Campus Box 149, 54124 Thessaloniki, Greece

²Julian Gröbner performed this research when he was at the European Commission Joint Research Centre, Environment Institute for Health and Consumer Protection, Physical and Chemical Exposure Unit, I-21020, Ispra, Italy. He is now at Physikalisch-Meteorologisches Observatorium Davos, PMOD/WRC, Dorfstrasse 33, 7260 Davos, Switzerland

³Mario Blumthaler is with the Institute of Medical Physics, Medical University of Innsbruck, 44 Muellerstrasse, A-6020 Innsbruck, Austria

⁴Gunther Seckmeyer is with the Institute of Meteorology and Climatology, University of Hannover, Herrenhaeuser Str 2, 30419 Hannover, Germany

⁵Ann R. Webb is with the University of Manchester, P.O. Box 88, Manchester M60 IQD, United Kingdom

⁶Tapani Koskela is with the Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland

⁷Peter Görts is with the Laboratory of Radiation Research, National Institute of Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA Bilthoven, The Netherlands

⁸Josef Schreder is with Calibration Measurement Software Solutions (CMS), Austria