Researchers from Dr. Zamin Kanji’s research group at ETH Zürich including Dr. Cuiqi Zhang and Dr. Michael Rösch have successfully installed and operated a fog monitor (Droplet Measurement Technologies; model FM-100) at the high-altitude research station Jungfraujoch (JFJ; 3580 m a.s.l., 46°33’ N, 7°59’ E), marking a major milestone in Switzerland’s contribution to the ACTRIS (Aerosol, Clouds and Trace Gases Research Infrastructure) cloud in situ (CIS) network. This pilot initiative is a critical step toward achieving Level 1a labelling for cloud in situ (CIS) measurements at JFJ, in accordance with ACTRIS standards.
A Major Step Toward ACTRIS CIS labelling
The FM-100, housed in a custom-built air-conditioned enclosure and equipped with a wind-adaptive cloud sampling inlet, is designed to enable uninterrupted, continuous measurement of two mandatory ACTRIS CIS variables:
- Liquid water content
- Droplet effective diameter
These measurements are essential for understanding cloud microphysics and their role in the climate system. Dr. Kanji’s team at ETH Zürich leads the CIS component of ACTRIS-CH, the Swiss national node of ACTRIS. The successful deployment at JFJ demonstrates Switzerland’s commitment to enhancing the European atmospheric observation network with high-quality in situ cloud measurement data.
Specialized Measurements: Ice Nucleating Particles
In addition to the mandatory cloud variables, Dr. Kanji’s team at ETH Zürich has also implemented continuous measurements of ice-nucleating particle (INP) number concentration at JFJ. INP monitoring provides critical insights into cloud phase transitions and precipitation processes, which further enriches the ACTRIS dataset.
About ACTRIS CIS
The ACTRIS Centre for Cloud In Situ Measurements (ACTRIS CIS) is a specialized component of ACTRIS dedicated to the standardized observation and quality control of cloud microphysical properties. It supports the harmonization of in situ cloud measurements across Europe by ensuring that data on cloud droplet size, phase, and concentration are consistent and comparable. ACTRIS-CIS plays a vital role in enabling research on cloud-aerosol interactions and their implications for climate and weather prediction.