Abstract
Aerosol catalysed formation of cloud droplets and ice crystals is of crucial importance to Earth’s climate. Yet, these processes remain insufficiently understood. The contribution of anthropogenic aerosol particles such as soot to cloud formation and climate is largely unconstrained. During their atmospheric lifetime, these microscopic black soot particles undergo atmospheric ageing processes, altering their cloud forming potential. Their contribution to cloud formation varies at different altitudes of the atmosphere. Join us on a trip through the atmosphere to explore how and where these tiny little black particles matter. Global climate model simulations encompassing new laboratory findings of O3-aged soot acting as cloud condensation nuclei and H2SO4-aged soot as ice nucleating particles reveal a reduction in cooling by anthropogenic aerosols, and an increased equilibrium climate sensitivity (warming in a future world with 2 * [CO2]). Warming can disproportionally impact regions like the Arctic due to climate feedbacks. Climate models struggle with the representation of the processes that buffer Arctic (mixed-phase) clouds from dissipating. Their longevity makes them critical drivers of radiative transfer demonstrating the need to understand their formation and persistence. Measurements of ice cloud forming aerosol in the Arctic are presented to better represent their variability in parameterizations that can be used in Arctic cloud models.
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).