An overview of current issues in the uptake of atmospheric trace gases by aerosols and clouds
Trace gas uptake by a variety of condensed phase materials on the Earths surface, including vegetation, rock, soil, ice, snow, fresh and marine surface waters, buildings and paved surfaces can play an important role in the transformation and environmental fate of many atmospheric species. Even more importantly, heterogeneous interactions of trace gases with liquid and solid cloud droplets and aerosol particulate matter (PM) strongly influence two critical atmospheric properties. First, heterogeneous uptake by PM and cloud droplets, of- ten coupled with surface and/or bulk phase reactions, can sig- nificantly alter the distribution of reactive atmospheric gases. Second, the uptake of trace gases, including water vapour, impacts important physical properties of atmospheric PM, such as size, optical properties, and ability to nucleate cloud droplets.