New Particle Formation in the Marine Boundary Layer

Aerosols play an important role in Earth's climate, as they interact with atmospheric radiation thereby inducing a radiative forcing. Such forcing occurs directly via the scattering and absorption of electromagnetic radiation propagating in the atmosphere, and indirectly from aerosol-induced changes in cloud properties (for example, changes in the cloud droplet count which modifies the albedo of clouds.) Primary aerosols are emitted from the Earth's surface to the atmosphere, typical sources are desert dust, combustion processes and sea salt. However aerosols can also form within the atmosphere, in a process known as new particle formation (NPF). NPF describes the process of low volatile vapor forming molecular clusters. By coagulation and condensation, aerosols can subsequently grow in size and act as cloud condensation nuclei (CCN). Since these low volatile trace gases are more likely to condense on already existing particles than form new clusters, NPF becomes particularly relevant in pristine regions. While recent major progress has been made in mirroring continental NPF within global Earth System Models (ESMs), the representation of marine NPF is still not fully captured in global models. In this talk I present how we improve the representation of marine NPF in global models, focusing on sulfur and iodine chemistry and NPF in the atmosphere.