Partner 13 - PSI (Switzerland)
Paul Scherrer Institute (PSI)

Expertise and experience of the organization
PSI in Switzerland is a centre for multi-disciplinary research and one of the world's leading user laboratories. With its 1200 employees it belongs as an autonomous institution to the Swiss ETH domain. The Laboratory of Atmospheric Chemistry (LAC) at PSI consists of about 35 researchers, including 15 PhD students. It has in-depth experience with the design of experiments to characterize physical and chemical properties of aerosols and has a strong interest in the impact of aerosols on air quality and climate. The laboratory operates a chamber facility for atmospheric chemistry simulation, as well as a continuous aerosol programme at the high Alpine research station Jungfraujoch (3580 m asl) within the Global Atmosphere Watch (GAW) program of the World Meteorological Organization (WMO). Additional activities include a mobile measuring van as well as a large number of other state of the art facilities for atmospheric chemistry research, both custom built and commercially available. CAM-x modelling is used for comparison with experimental data. The LAC is currently involved in 9 EC projects, including e.g. EUCAARI and EUSAAR.

Role and contribution

PSI will lead WP 3 together with partner 6 (CNRS). Measurements of a wide variety of aerosol variables, use of state of the art statistical tools for source apportionment.

Principal personnel involved
Prof. Urs Baltensperger is Head of the Laboratory of Atmospheric Chemistry at PSI and Prof. at ETH Zurich. His research concerns the formation of secondary organic aerosol from gaseous precursors in a simulation chamber, as well as the physical and chemical characterisation of atmospheric aerosols and their impact on climate. He is Chairman of the Scientific Advisory Group for Aerosols within the Global Atmosphere Watch programme of the World Meteorological Organization (WMO), and is President of the Commission of Atmospheric Chemistry and Physics of the Swiss Academy of Natural Sciences. He is author of more than 140 peer-reviewed papers. He is the recipient of the 18th Prof. Dr. Vilho Vaisala Award of the WMO.
Dr. André Prévôt is Head of the Gasphase and Aerosol Chemistry Group at PSI and lecturer at ETH Zurich. His research deals with the characterisation of the chemical composition of aerosols and trace gases and their transformation in the lower troposphere. Advanced methods like aerosol mass spectrometry, 14C-analyses, synchrotron x-ray fluorescence are used as input for source apportionment studies. Spatial gradients of the chemical composition and physical properties are assessed with our mobile laboratory including fast response instrumentation. The transformation of selected pollutants is investigated in the PSI smog chamber. Finally, a 3-dimensional Eulerian model is used to integrate the atmospheric processes on a larger scale. He is author of more than 60 peer-reviewed papers.

Selected relevant publications
Bukowiecki, N., R. Gehrig, M. Hill, P. Lienemann, C.N. Zwicky, B. Buchmann, E. Weingartner, U. Baltensperger (2007): Iron, manganese and copper emitted by cargo and passenger trains in Zürich (Switzerland): Size-segregated mass concentrations in ambient air, Atmos. Environ., 41, 878-889,
Kalberer, M., D. Paulsen, M. Sax, M. Steinbacher, J. Dommen, A.S.H. Prévôt, R. Fisseha, E. Weingartner, V. Frankevich, R. Zenobi, U. Baltensperger (2004): Identification of polymers as major components of atmospheric organic aerosols, Science, 303, 1659-1662,
Lanz, V.A., M.R. Alfarra, U. Baltensperger, B. Buchmann, C. Hueglin, A.S.H. Prévôt (2007): Source apportionment of submicron organic aerosols at an urban site by factor analytical modelling of aerosol mass spectra, Atmos. Chem. Phys., 7, 1503-1522.
Szidat, S., A. S. H. Prévôt, J. Sanradewi, M. R. Alfarra, H. A. Synal, L. Wacker, U. Baltensperger (2007): Dominant impact of residential wood burning on particulate matter in alpine valleys during winter, Geophys. Res. Lett., 34, doi:10.1029/2006GL028325,
Szidat, S., T.M. Jenk, H.-A. Synal, M. Kalberer, L. Wacker, I. Hajdas, A. Kasper-Giebl, U. Baltensperger (2006): Contributions of fossil fuel, biomass-burning, and biogenic emissions to carbonaceous aerosols in Zurich as traced by 14C, J. Geophys. Res., 111, doi:10-1029/2005JD006590.

FP7 EC MEGAPOLI, 2008-2011