Abstract: Global climate models poorly represent mixed-phase clouds in a realistic way, which leads to uncertainties in cloud radiative forcing and precipitation. Mixed-phase clouds are highly sensitive to microphysical processes, which can either sustain or break down the unstable mixed-phase state and thereby determine the longevity of the clouds and their radiative impact. They are influenced by the availability of aerosol particles, which can act as ice nucleating particle (INP) or cloud condensation nuclei (CCN).
This talk will present preliminary results from the FORCeS ice experiment (FOR-ICE), where we investigated which processes are crucial for a realistic representation of cloud ice and supercooled water in three global climate models (ECHAM-HAM, NorESM, EC-Earth). A specific focus of the experiments is on secondary ice production (SIP) - which apart from one mechanism (rime splintering) is not represented in models. We evaluated the importance of three SIP mechanisms combined (rime splintering, ice-ice collisions, and droplet shattering) compared to all other processes that can modulate ice mass and number in mixed-phase clouds: ice nucleation, sedimentation, and transport of ice crystals, and the Wegener-Bergeron-Findeisen process.
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).