Research project AC3S: Aerosols, Convection, Clouds, and Climate Sensitivity

Interactions between anthropogenic aerosol particles and clouds are the largest source of uncertainty in the historical radiative forcing of climate. Aerosol effects on tropical deep convective clouds could constitute a major component of this forcing, but the underlying physical mechanisms are poorly understood, and the associated global climate forcing has not been rigorously quantified before. These knowledge gaps have been highlighted as an urgent research challenge in recent community assessment reports.

AC3S seeks to address this challenge by applying state-of-the-art observational and modeling techniques that span the disciplines of aerosol-cloud interactions and climate science.

First, we will perform regional analysis of satellite observations, in-situ aircraft measurements, and high-resolution numerical simulations to investigate the physical mechanisms that govern the interactions between aerosols and tropical deep convective clouds.

Second, we will analyze global satellite observations to rigorously assess the global climate forcing from these aerosol-cloud interactions.

Finally, we will synthesize the evidence and quantify the implications of the results for Earth’s climate sensitivity to carbon-dioxide forcing and 21st century global warming.