Discerning the Impact of Aerosols on Cloud and Storm Intensity: Importance for Weather and Climate

The radiative forcing associated with aerosol-cloud interactions remains one of the largest uncertainties in our understanding of the Earth's climate. Among the many components of aerosol-cloud interactions, the influences of aerosols on the properties of vertically-developed convective clouds and the associated storms have been at the center of significant debate in recent years. Our understanding of aerosol impacts on convective cloud microphysics, dynamics and radiative properties has greatly progressed over the past ~20 years, however, the role of aerosols in invigorating or enervating convective updrafts remains unresolved. Towards resolving this debate, a succession of multi-agency field measurement campaigns took place in the southeastern Texas region during the period from October 2021 through September 2022. The major objective of these campaigns was to collect state-of-the-art detailed observations in a coastal-urban environment to study the interactions of coastal and urban circulations, anthropogenic and natural aerosols, and convective clouds to facilitate high-resolution modeling studies of aerosol-convection interactions. This presentation will focus on completed and ongoing studies related to the multi-scale nature of aerosol-cloud interactions and the building block investigations to disentangle the co-varying aerosol and meteorological effects. Early results using both machine learning, observation-driven approaches and high-resolution modeling studies will be presented showing some evidence of invigoration by aerosols, but also highlighting the remaining challenges to definitive quantification of these aerosol impacts. The relevance of these studies to weather forecasting, extreme weather events and climate projections will be presented with a particular focus on the impacts to the residents of the southeastern Texas region.