BIO-MAIDO

BIO-MAIDO, funded by the French National Research Agency (ANR), aims to gain a better understanding of the chemical and biological mechanisms in the presence of clouds that control the formation of organic matter on fine airborne particles. To this end, an intensive measurement campaign is currently underway (March 11 to April 7) at the Maïdo observatory and four other sites on the Maïdo planèze.
Reunion Island’s tropical environment offers optimal conditions for BIO-MAIDO’s objectives. First of all, the island’s forests, with their high levels of sunshine and favorable temperatures, emit numerous compounds in the form of gases, which form organic matter on fine particles. In addition, the high occurrence of slope cloud formation on the Maïdo planèze allows us to assess the influence of clouds on this new particle formation pathway.
The sophisticated instrumentation deployed during the campaign will enable us to measure compounds emitted by vegetation, study the physico-chemical properties of fine particles and measure the bio-physico-chemical composition of clouds formed during the ascent of humid air from the ocean. Marine and anthropogenic sources will be assessed, using the results of the OCTAVE (Oxygenated Compounds in the Tropical Atmosphere: Variability and Exchange) project to identify chemical markers of these sources and calculate back-trajectories.
After the campaign, this set of observations will be analyzed to assess the formation of organic compounds on fine particles in tropical atmospheres. These data will be used to initialize models used to interpret in situ data. The data from the campaign will also be used to better constrain the models in order to improve the way they represent the formation of these organic compounds, whether in the air or in cloud drops, by taking into account biological activity in clouds, which has never been studied to date.

Eight laboratories and some twenty scientists are involved. LACy (Université de La Réunion, CNRS, Météo-France), LOA (Université de Lille, CNRS), LaMP (Université de Clermont Auvergne, CNRS), IGE (Université de Grenoble, CNRS, IRD, INP), LSCE (CNRS, CEA, Université Versaille Saint-Quentin), LA (Université de Toulouse, CNRS), CNRM (Météo-France, CNRS) and LaRGE (Université Antille-Guyane).