The substantial uncertainty surrounding regional and global anthropogenic climate change is largely due to our limited understanding of molecular-scale processes that govern atmospheric systems. These processes critically influence cloud properties and their climate impacts by modulating particle formation and growth. The atomistic properties of individual aerosol particles, their interactions with surrounding vapor-phase molecules, and the transport processes within the particle phase occur on temporal and spatial scales that are accessible through only a few specialized techniques. Among these, molecular simulations—such as molecular dynamics and Monte Carlo methods—and single-molecule experiments stand out for their uniquely high spatial and temporal resolution. Depending on the system, a variety of approaches are used—ranging from classical and reactive force fields to ab initio methods, with recent advances in machine learning further enhancing their capabilities. These approaches effectively complement traditional experimental and modeling techniques, and their recent adoption in characterizing molecular-scale properties is driving the emergence of a new interdisciplinary field at the intersection of molecular modeling and aerosol science.
We invite contributions that apply single-particle or molecular-scale approaches to investigate aerosol properties—such as composition, structure, phase state, and shape—and processes critical to understanding the climate and health effects of aerosols. These processes may include new particle formation, cloud droplet and ice nucleation, and chemical reactions.