Atmospheric aerosol particles play an important role in forming low-level clouds in marine environments. Understanding their properties in clean and polluted air masses provides insights in evaluating aerosol radiative forcings. Radon-based air mass classification is a powerful tool in isolating air masses of marine origins. Aerosol measurements help identify local pollution interference in greenhouse gas baseline determination. About the speaker:Xuemeng Chen (Ava) is a university researcher working in the Institute for Atmospheric and Earth System Research (INAR) of the University of Helsinki. Her main research focus is on atmospheric clusters and nanoparticles, especially air ion properties as well as their formation and linkage to atmospheric radioactivity and electricity. In NuClim, she is responsible for NAIS, PSM, ACSM and PTR-ToF measurements at the ENA station (Graciosa, Azores) and leads WP3 data analysis and interpretation on aerosols and clouds.