GAW Longterm Aerosol Monitoring at the High-Altitude Research Station Jungfraujoch

Duration: Continuous since 1995
Funding: GAW-CH coordinated by the Federal Office of Meteorology and Climatology (MeteoSwiss)
Contact: Benjamin Brem (benjamin.brem@psi.ch) and Martin Gysel-Beer (martin.gysel@psi.ch)

Table of Contents

In 1988 the Paul Scherrer Institute (PSI) initiated an aerosol research programme at the high Alpine Research Station Jungfraujoch (3580 m asl). Since 1995 the Laboratory of Atmospheric Chemistry at PSI has been responsible for the continuous aerosol measurements performed at Jungfraujoch within the Swiss contribution to the Global Atmosphere Watch (GAW) program of the World Meteorological Organization. In Europe, the GAW program is tightly linked to the Aerosol, Clouds and Traces Gases Research Infrastructure (ACTRIS). This site also serves as a platform for international research projects to investigate aerosol processes and environmental impacts through e.g. their interaction with solar radiation or clouds. See also ACTRIS Switzerland.

The broader aim of our longterm observations and associated research projects performed at the high-altitude research station Jungfraujoch is to achieve a better understanding of the live-cycle of atmospheric aerosols and their climate and weather impacts. Given the location high up in the alps, its is possible to probe free tropospheric background aerosol and to investigate transport events of particles originating from within the polluted planetary boundary layer, where the vast majority of aerosol emissions occur. Specific topics include:

• An overview of more than 20 years of aerosol observation at the high altitude research station Jungfraujoch is given in Bukowiecki et al., 2016 (covers studies published until 2016)
• Spatial variation of aerosol properties on global scale (e.g. Laj et al., 2020) and trend analyses (e.g. Collaud Coen et al., 2020)
• Soot particle properties and associated ability to form cloud droplets (e.g. Motos et al., 2020; Motos et al., 2019)
• Provision of comprehensive data sets (e.g. Schmale et al., 2018; Schmale et al., 2017) for benchmarking of global model simulations (e.g. Fanourgakis et al., 2019)
• Processes shaping the aerosol particle size distributions, including new particle formation and subsequent growth (e.g. Bianchi et al. 2016; Tröstl et al., 2016; Herrmann et al., 2015)
• Various aspects of aerosol-cloud interactions in warm clouds (liquid water clouds), for example investigating the interplay of dynamics (updraft) and number concentration of potential cloud condensation nuclei in determining cloud droplet number concentration (e.g. Hoyle et al., 2016; Hammer et al., 2014). Aforementioned two parameters are intrinsically coupled through cloud peak supersaturation and cut-off diameter above which particles activate to form cloud droplet.
• Physico-chemical characterization of ice nucleating particles in mixed-phase and glaciated clouds (e.g. Brunner et al., 2022; Brunner et al., 2021; Kupiszewski et al., 2016)
• Aerosol chemical composition (e.g. Fröhlich et al., 2015)
• Properties of aerosols in distinct plumes from sources such as volcanoes or Saharan dust after intra- or intercontinental long-range transport (e.g. Bukowiecki et al., 2011; Collaud Coen et al., 2004)
• Vertical transport of pollutants from the boundary layer to the Jungfraujoch (e.g. Collaud Coen et al., 2011)
• Hygroscopic water uptake by particles as a function of relative humidity and their ability to act as cloud condensation nuclei (e.g. Kammermann et al., 2010; Jurányi et al., 2011)

Environmental impacts of atmospheric aerosols depend on many different physical, optical and chemical properties of the particles which are highly variable in time and space. Furthermore, many additional atmospheric parameters influence aerosol processes driving these impacts. In order to understand these processes and to quantify aerosol impacts, it is therefore of crucial importance to run multi-site and multi-parameter atmospheric observation networks and to make acquired data available to the research community.

Visualizations of current concentration and properties of aerosol particles observed at the Jungfraujoch research station are presented in near real-time at: https://www.actris.ch/data/jungfraujoch-national-facility/

Quality controlled aerosol data are made available through the portal of the EBAS database infrastructure, which serves as international data center hosting atmospheric composition data from the GAW (https://www.gaw-wdca.org/) and several other observation networks.

The following aerosol parameters are measured on a continuous basis at the Jungfraujoch:

• Die Aerosol-Jäger vom Jungfraujoch - Interview with Benjamin Brem on more than 25 years aerosol research at Jungfraujoch
• High-ranking visitor on the Jungfraujoch Research Station - US Ambassador Scott Miller on visit during the "Jungfraujoch Carbon Balance Campaign"
• “Kleine Partikel, Grosse Auswirkung” in PROCLIM FLASH – Schweizer Zeitschrift zu Klima und Globalem Wandel, Swiss Academy of Sciences, Nr. 75, p. 20-21, Winter 2021. (German)
• "Forschen über den Wolken" in “5232 – Das Magazin des Paul Scherrer Instituts”, Issue 02-2019. (German)
• "Der Staubsauger der Sphinx" in Neue Zürcher Zeitung, 16.05.2015. (German)
• Information movie shown at the Jungfraujoch on occasion of the Jungfrau Railway Centenary (2012)

• Realtime visualization of aerosol parameters at Jungfraujoch.
• Aerosol, clouds and trace gase research infrastructure, ACTRIS.
• ACTRIS Switzerland
• High Altitude Research Stations Jungfraujoch & Gornergrat, HFSJG