Model Development

Simulating clouds in a global climate model (GCM) requires simulating the entire package of cloud related processes. Clouds usually form when there is upward motion (cooling) of air which can be caused by small-scale convective events or large-scale ascent of air masses e.g. along a warm front of a cyclone. For each of these cloud formation pathways we have to calculate if a cloud forms, how large it is, and how many cloud droplets or ice crystals are formed. Inside a cloud processes like freezing of cloud droplets, growing/shrinking of cloud droplets and ice crystals, aggregation of ice crystals, or riming of cloud droplets on ice crystals have to be simulated. Finally, cloud droplets can form rain drops and ice crystals that can aggregate to snowflakes and fall out which reduces the cloud mass and leads to precipitation at the ground.
Cloud droplet and ice crystal formation depend at least partly on aerosol concentrations and properties which is why our cloud model is coupled to an aerosol model which allows us to study aerosol-cloud-interactions.

In general, we work on improving all these processes and their interactions in the cloud model. For more information, please contact Steffen Münch ()