Final Report Summary - ACI-AMS (Determining how the chemical and physical properties of single aerosol particles affect their cloud forming potential) It is not fully understood how aerosol particles affect the development of clouds or the extent to which they affect the cycles of water and radiant energy in the climate system as a whole. Hence achieving a better understanding of how aerosol particles affect clouds and consequently climate radiation is important both to the scientific community and to policy makers. This project addressed the uncertainties between the interactions of aerosol particles and cloud droplets at the puy de Dome station in central France. One of the unique and exceptional aspects of this project is that the resulting measurements provided information on the interactions of aerosol particles and cloud droplets in the planetary boundary layer but also in the free troposphere. The puy de Dome station is currently the only site in Europe, which is an altitude site and is equipped with LIDAR to measure the boundary layer height. The Laboratoire de Météorologie Physique UBP/CNRS at the University Blaise Pascal, Clermont Ferrand is exceptionally experienced in the field of atmospheric science and their expertise encompasses both experimental and theoretical approaches. The work to fulfill the aims of this project was performed with a suite of instrumentation measuring aerosol hygroscopic and cloud nucleating properties, aerosol size distribution, optical properties, and aerosol chemical composition. Two intensive field campaigns were performed in the framework of this project (one during the summer and a second during the winter) at the Puy de Dome station. During both experiments several cloud events occurred on the site and were used to interpret aerosol cloud interactions (Asmi et al., 2012). These results were presented at the European aerosol conference and also at the annual ACTRIS (European, aerosol, cloud, monitoring network) meeting (2014). During the winter campaign in 2012, several researchers from around Europe performed measurements at the puy de Dome site, allowing us to create new collaborations with several different research groups including Ulrich Bundke from the University of Franckfurt in Germany (Ice nucleation chamber) and from the University of Helsinki, and Eija Asmi from the Finish meteorological institute in Finland (Aerosol ion mass spectrometer).The planned period of integration of Dr. Evelyn Freney had an important influence on her future career by offering her an opportunity to accumulate valuable research experience in the field of aerosol particle-cloud interactions. The approach was to perform field based measurements on the hygroscopic and chemical composition of atmospheric aerosol particles and then to assess the implications of these measurements in atmospheric science. Dr. Freney is an early-career scientist who is developing a promising career in research. Thanks to the Marie Curie international reintegration grant Dr. Evelyn Freney successfully applied for a permanent research position within the CNRS in 2012."
