Abstract: Despite their small contribution to the overall composition of air, aerosol particles play and important role in the Earth's atmosphere. Their liquid or solid phase distinguishes them from gas molecules, providing surfaces for water and other vapors to condense and distinct chemical mechanisms to take place on. The sizes, chemical composition and concentrations of aerosol particles vary considerably over space and time, which presents a challenge for representing them in air quality and climate models. I will highlight some recent advances in our understanding of the mechanisms governing the loadings and properties of atmospheric aerosol particles and their precursors. In particular, I will focus on the phase transitions that govern the dynamic interaction of the atmospheric particulate phase with the gas phase - including phenomena like formation of new particles via nucleation, condensation and evaporation, but also the interaction of atmospheric particulate constituents with water vapour which is at the heart of cloud formation processes in the present atmosphere. I will place particular emphasis on the organic aerosol fraction, as this complex mixture of various chemical species is still one of the major elements of uncertainty in our understanding of the life cycle, budgets and impacts of atmospheric aerosol particles. Finally, I will place the detailed molecular knowledge in the context of improving the estimates of aerosol particle impacts on climate.
What is the Joint Oslo Seminar (JOS):
Atmospheric and climate sciences have a stronghold in Oslo among the four institutions University of Oslo, the Meteorological Institute, CICERO and NILU. This joint seminar invites renowned international experts to contribute to an informal series of lectures, meant to create interaction with the Oslo atmospheric and climate science community on recent highlights and analysis in the field. All seminars will be held on Thursdays (Noon -1pm) and lunch (sandwiches) will be served on a “first-come-first-served”-basis.