ReCLEAN showed a strong presence at the ACTRIS Switzerland meeting at the Federal Office of Meteorology and Climatology MeteoSwiss premises in Payerne on 3 July 2025.

The meeting brought together leading scientists and collaborators from across the Swiss atmospheric research community, offering a platform to share results, discuss methodologies, and strengthen ongoing partnerships. ReCLEAN, a joint initiative spearheaded within the ETH domain, stood out as a focal point, showcasing its unique approach to tackling nitrogen-related processes and their impact on air quality, climate, and cloud formation.

At the heart of the discussions were results from the 2024 ReCLEAN field campaign in Payerne, a region central to Swiss atmospheric monitoring. The campaign, which leveraged high-resolution instrumentation and coordinated efforts among several research institutions, is already yielding valuable insights into reactive nitrogen species and their role in aerosol-cloud interactions.

In addition to ReCLEAN, the meeting featured related efforts that complement its goals. Presentations covered the CleanCloud ACI framework and its CHOPIN and PIANO campaigns, as well as the 2023 PÉRICLÈS (PayernE lidaR and Insitu detection of fluorescent biomass burning, bioaerosol and dust partiCLES and their cloud impacts) campaign—focused on lidar and in-situ detection of bioaerosols, dust, and biomass burning particles—and its continuation under the SNSF LipicAir project.

These initiatives, though distinct in scope, all feed into the broader vision of improving our understanding of how atmospheric particles interact with clouds, climate systems, and human health.

Hosted by the Paul Scherrer Institute (PSI) and supported by ACTRIS, the event affirmed Switzerland’s leadership in atmospheric science and highlighted ReCLEAN as a model for future interdisciplinary collaboration.