BIOlogical and photochemical impacts on cloud oxidant CAPacity


Gilles Mailhot (ICCF)

Project type



Project duration

Start Date

December 30, 2013

End Date

June 30, 2019

The BIOCAP project has a double objective. First of all to describe more exactly the content of the aqueous phase of the clouds chemically or biologically and to understand and measure the significance of the reactions, taking place within the cloud, on the transformation of atmospheric compounds or in other words on the capacity of this environment to oxidize the organic compounds. Indeed, the cloud is a major actor of the atmosphere and has certainly an impact on the climate change. The first difficulty is the fact that the cloud is a dynamic environment, composed of gas, solid particles, also called aerosols, and of droplets of water. Through the transfers of the chemical compounds between phases, the droplet of water is a medium with an important reactivity of chemical or biological nature. The benefits from our project are scientific because we obtained new information on the cloud functioning which is still unknown. The work on the activity of microorganisms is really new. Our results has also a long-term societal impact because the models of prediction of the climate are based on the processes occurring in clouds.

The most notable results were to highlight and measure for the first time amino acids and iron-specific organic ligands, which are important actors in the cloud aqueous phase. At the same time, we finalized a method to estimate the capacity of transformation of chemical compounds present in cloud water and showed the importance of microorganisms in these processes. These transformations and the life times of the organic pollutants present in cloud aqueous phase are essential data to better predict the climate change.

The team


Collaborations françaises: ICCF, LAMP