Abstract:
Knowing how rainfall responds in a changing climate remains one of the most important challenges in climate science. Yet global-scale rainfall change is typically explained using cloudless energetic arguments of limited utility, while climate models are comprehensive yet are often treated as black boxes. In this talk, I bridge the gap between theory and models while examining two cases: the global mean rainfall response to surface warming, and the response to stratospheric aerosols from volcanic eruptions or geoengineering. In both cases, intermodel differences in rainfall response are shown to be closely tied to differences in how cloud properties change, reflecting modulation by cloud radiative effects. I further disentangle how stratospheric aerosols reduce global mean precipitation, using this case to lay out a process-based explanation of global rainfall change that explicitly incorporates convection and cloud processes. These efforts advance understanding of global precipitation change beyond simplistic first-order approximations, and identify cloud representation in models as a key issue to address for tighter rainfall projections.
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.
- Normally seminars will be held on Thursdays (12:15 pm -1pm).