The Jungfraujoch is a saddle connecting two famous, high-mountain peaks in the Swiss Alps: the Jungfrau and the Mönch. This unique geographical location is the site of Europe’s highest railway station (elevation 3 454 m), as well as a world-class research station. The railway was completed in 1912 and is accessible to the general public. The research station also has a long and illustrious history. It was first proposed in 1894 by the Swiss Federal Council as a condition for the building of the railway. Today, the station is operated by the International Foundation High Altitude Research Stations Jungfraujoch and  Gornergrat. It is comprised of research observatories and laboratories, workshops, a library, accommodation facilities, and the Sphinx Observatory (elevation: 3 580 m), which houses an astronomical dome as well as the atmospheric research facilities described below.

Aerosol in situ observations

Aerosol measurements at the Jungfraujoch Observatory were first initiated by the Paul Scherrer Institute in 1988, and continuous aerosol monitoring has been performed since 1995. These continuous measurements are part of the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization, and of ACTRIS. Measured aerosol parameters include particle number concentrations and size distributions, aerosol scattering and absorption coefficients, and aerosol chemical composition. Full details of the measurement program can be found here.

Long term aerosol measurements from the Jungfraujoch

Trace gas in situ observations

There is a long history of continuous trace gas measurements performed by Empa at the Jungfraujoch. NOx and the following six stable VOCs are measured continuously: Ethane, propane, n-butane, methylpropane, benzene, and toluene. For the measurement of NO2 a mid-infrared direct quantum cascade laser (QCL) absorption spectrometer for the specific analysis of NO2 (MIRO Analytical) is used. NO measurements are performed with a CLD (CLD 89p) analyser. For the measurement of VOCs a specific Medusa GCMS (gas chromatograph – mass spectrometer) is used, which is also measuring halogenated greenhouse gases (CFCs, HCFCs, HFCs, PFCs, SF6 and HFOs) within the global AGAGE network.

Measurements of NOx and VOCs are also part of the Swiss network on air pollutants and in addition, VOCs are part of the Swiss national CLIMGAS-CH project under common the management of Empa and FOEN (Swiss Federal Office for the Environment).

Image 1: Medusa GCMS for the continuous analysis of stable VOCs and halogenated greenhouse gases.
Image 2: Measurement data of benzene at Jungfraujoch together with other background stations in Europe.

Cloud in situ observations

The HINC-Auto continuously measuring INP concentrations at Jungfraujoch
Photo: Cuiqi Zhang

Ice nucleating particles, or INPs, are special types of aerosols that aid in the formation of ice clouds. INP concentrations are continuously measured at the Jungfraujoch Observatory with an instrument known as the HINC-Auto. The HINC-​Auto is based on the same op­er­a­tional prin­ciple and design of the Uni­ver­sity of Toronto Con­tinu­ous Flow Dif­fu­sion Cham­ber (UT-​CFDC) and the Ho­ri­zontal Ice Nuc­le­ation Cham­ber (HINC). It has been mod­i­fied to en­hance ac­cur­acy, port­ab­il­ity and to be run autonom­ously and con­tinu­ously at meas­ure­ment sta­tions.

The goals of this measurement program are to obtain in­sight on the seasonal and an­nual INP con­cen­tra­tion cycle, to dis­tin­guish back­ground INP con­cen­tra­tions from concentrations during in­tru­sions when air masses ar­rive from the con­vect­ively lif­ted bound­ary layer air or North Africa (Saha­ran Dust Events), and to un­der­stand the role of aer­o­sol per­turb­a­tions on the INP con­cen­tra­tion and thus cloud form­a­tion.

The re­al­-time INP con­cen­tra­tions meas­ured at the High Alpine Re­search Sta­tion Jung­frau­joch are shown here as well as at ETH IAC Ice Nucleation Research . If you would like to use the data, do not hes­it­ate to get in touch with us. An ex­ample of the data on INP con­cen­tra­tions can be found here and the data us­age policies are de­scribed here.