Assessing the Dependence of Aerosol-Cloud Interactions on Low-Cloud Mesoscale Morphology with ARM Observations

Aerosol-cloud interactions (ACIs) in the marine boundary layer (MBL) clouds and their radiative forcing remain the leading uncertainty in our forcing estimate. ACIs in the MBL are state-dependent and time-dependent, which makes them hard to model and contributes to the current understanding. MBL cloud morphology has been shown to play an important role in qualitatively determining cloud adjustments to aerosols by both observational and modeling studies. However, our understanding of the morphology-dependence of ACIs in the MBL clouds is still in its infancy.

This will be the first study that uses comprehensive ship-track samples and ground-based observations to study aerosol-cloud interactions. Our approach addresses the attribution problem by focusing on ship-tracks, captures the temporal evolution of ACIs by estimating the age of ship-tracks, avoids time-dependent satellite retrieval biases by using high-quality ground-based ARM data, and is always aware of the background cloud morphology type and meteorological environment. Results from our investigation will provide observational constraints on the behavior of aerosol-cloud interactions and cloud morphology properties.