Understanding the complex physical and chemical transformations of biogenic and anthropogenic emissions is essential for predicting their effects on air quality and climate. This session focuses on investigations ranging from fundamental molecular-level mechanisms to complete chemical mechanisms that drive and explain these large-scale atmospheric processes.

We welcome contributions that bridge the gap between microscopic processes and macroscopic atmospheric phenomena, spanning gas-phase kinetics, multiphase chemistry, and the nanophysics that drives aerosol forcing. Topics of interest include: 1) computational and theoretical advances, including quantum chemistry, molecular dynamics simulations, and machine learning; 2) experimental insights from laboratory, atmospheric simulation chamber, and field studies; and 3) the application of novel experimental techniques and the use of research infrastructures (such as ACTRIS, ICOS, and IAGOS) for detailed process studies.