Start of the TNA ATMO-ACCESS NetAeFoCs project at OPAR-Maido: Study of interactions between aerosols, fog and clouds under natural and anthropogenic influences.

View of the ACES instrumented container (TNA ATMO-ACCESS NetAeFoCs project) at OPAR-Maido and some of the team members from Stockholm University (Department of Environmental Sciences – ACES) and OSU-Réunion (October 12, 2023) (credit: Olivier Magand, OSU-R).

As part of the TNA ATMO-ACCESS NetAeFoCs project, the team(*) from Stockholm University (Department of Environmental Sciences – ACES), supported by and in collaboration with the Observatoire des Sciences de l’Univers de La Réunion (OSU-R), the Laboratoire de l’Atmosphère et des Cyclones (LACy) and French partners carrying out continuous on-site measurements (LaMP, LSCE…), is aiming to collect atmospheric observation data at the Observatoire Physique de l’Atmosphère de La Réunion (OPAR) at Le Maïdo (OSU-R measurement station). ), aims to collect data from atmospheric observations at the Observatoire de Physique de l’Atmosphère de La Réunion (OPAR) at Le Maïdo (OSU-R’s measurement station) to fill in the knowledge gaps that are absolutely essential to understand the improvement of models dedicated to the functioning of the atmospheric system (molecular model, cloud distribution…) on a regional or even global scale.

At the Maïdo observatory, we plan to record the composition and properties of aerosols and clouds in detail, using state-of-the-art observational equipment. The instruments are installed in a specially designed mobile laboratory (20-foot container). The latter has already been used to study aerosol-mist-cloud interactions in Italy’s Po Valley (FAIRARI campaign supported by ATMO-ACCESS) and during the ARTofMELT 2023 expedition aboard the Swedish icebreaker Oden. The OPAR at Maïdo is the 3rd major measurement station visited by this mobile laboratory.

After several weeks of ocean crossing, the container was finally installed at the Maïdo observatory on October 10, 2023, in a sea of clouds revealing the site’s potential for studying this component. The field campaign officially began on October 12, after 2 days of set-up, and will continue for at least 6 months, with continuous measurements of aerosols, clouds and atmospheric chemical compounds during the austral summer and cyclone season. In addition to ATMO-ACCESS, the field campaign is supported by the European Research Council and the Knut and Alice Wallenberg Foundation, Sweden.

(*) Project leaders (Ilona Riipinen, Claudia Mohr – currently at PSI, Switzerland – and Paul Zieger), PhDs (Almuth Neuberger, Lea Haberstock and Fredrik Mattsson), post-docs (Liine Heikkinen and Yvette Gramlich) (

TNA project contact : Paul Zieger (

OSU-Reunion coordinator contact :  Olivier Magand (

Schematic view of the atmospheric measurement instruments deployed during the OPAR-Maido campaign (OSU-Reunion) in the ACES container (credit: Department of Environmental Sciences, Stockholm University).