Abstract:
Aerosols arguably remain the single greatest uncertainty among anthropogenic perturbations of the climate system. In particular the effects of aerosol-cloud interactions on the hydrological cycle remain highly uncertain.
Aerosol effects on precipitation have traditionally been assessed bottom-up, modelling and observing the chain of processes from aerosol emission, microphysical transformations, acting as cloud condensation and ice nuclei, via cloud microphysics and radiative effects to precipitation formation of individual clouds and cloud fields. However, this relies on a complete understanding of a very complex and uncertain process chain and has been shown to be subject to large uncertainties.
In this presentation, I will critically review some of the achievements made towards quantifying aerosol effects on precipitation – with a focus on bridging the scales.
Starting from the process scale, I will explore pathways for aerosol effects on precipitation and our ability to simulate and observationally constrain the relevant processes. I will further show that the assessment of precipitation changes in an energetic framework (because the associated change in latent heat release needs to be balanced by surface or top-of-atmosphere fluxes or compensated for by energy divergence/convergence), provides a powerful constraint on regional scale precipitation.
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.