An observational strategy for improving understanding of clouds and aerosols over the Southern Ocean

Clouds over the Southern Ocean play a major role in climate. The Southern Ocean region is one of the cloudiest on the planet, and as such helps determine its albedo. Evidence suggests that the Earth's climate sensitivity and the location of the Intertropical Convergence Zone are both dependent upon Southern Ocean clouds. Clouds in the region are sensitive to atmospheric aerosols that serve to act as cloud condensate nuclei for the liquid drop activation and as ice nuclei determining the degree of glaciation. Because the Southern Ocean is a pristine region that for the most part is unaffected by anthropogenic pollutants, it can serve as a useful proxy for preindustrial conditions on Earth in a way that the northern hemisphere extratropics cannot. Clouds and aerosols over the Southern Ocean remain poorly observed and understood. Satellite measurements, while critical, are insufficient on their own to provide the observations necessary to fully understand Southern Ocean clouds and represent them accurately in climate models. In this presentation, I will detail the key scientific challenges for understanding clouds and aerosols over the Southern Ocean and lay out a hypothesis-driven strategy to guide future field observations to address these challenges.