Impacts of distant pollution sources on microphysical transitions in Arctic clouds
A growing body of research indicates that biomass and industrial aerosols from mid-latitudes have a broad range of effects on arctic climatological systems. Pollutant aerosols directly and indirectly perturb solar reflection and thermal radiative emission in the atmosphere, and soot accelerates melting when it accumulates on snow. Nonetheless, much remains unknown about how pollution plumes are modifying arctic cloud properties and precipitation. Consequently, the impact of pollution on the arctic climate system is not well understood. Past research into aerosol-cloud-precipitation interactions in the Arctic has generally focused on small time and spatial scales, using a combination of aircraft and numerical modeling work. Less research has investigated these processes over climatological time scales and pan-Arctic spatial scales, the scales that are particularly relevant to guide and evaluate precipitation formation in larger scale climate models. Using a range of observational techniques for studying aerosol-cloud-precipitation-climate interactions, including ground-based and space-based approaches, the researchers will assess the following question: When particulate pollution reaches the Arctic, is it associated with a modification of cloud properties and an inhibition of ice crystal precipitation from super-cooled, low-level Arctic liquid clouds? The knowledge generated from this study will contribute to a better understanding of the impact of biomass burning and industrial aerosols on the arctic climate system.