The Puys chain is under the frequent influence of westerly winds bringing oceanic air masses, because there is no important montain from the Atlantic Ocean. Humid air condensates as it rises in altitude in contact with the Puy chain. The Puy de Dôme is then a site frequently in cloudy conditions and therefore ideal for the in situ study of clouds; this is also the only place in France where clouds have been collected and analyzed regularly since the beginning of the 2000s. The liquid cloud droplets are collected using a cloud collector which then allows measurements of chemical and microbiological parameters. This site is the only one in Europe to characterize the micro-organism in the cloud water and for this motivation, the chalet is equipped with a microbiology room to work in sterile conditions. The physical parameters of the clouds (number and diameter of droplets) are measured on the rooftop of the observatory, by direct scattering laser spectrophotometer (Gerber Particulate Volume Monitor).

Contacts : Laurent Deguillaume/Angelica Bianco