Cirrus formation in particle-based aerosol-cloud microphysics

We developed an ice phase extension for the PySDM Python package. PySDM is used for simulating the microphysics of population of particles, e.g. for modeling liquid droplets and their interactions with aerosol in clouds. PySDM uses the particle-based approach (‘super droplet method’) and features Monte-Carlo type solvers for processes such as collisions, coagulation, breakup, and freezing.

Our aim is to adapt that framework for the simulation of (pure) ice clouds in the cirrus temperature regime. Ice super particles are affected by homogeneous freezing of solution droplets, deposition nucleation, growth by vapor deposition and sedimentation. The main research question is the investigation of in-situ ice formation and sedimentation rates of in-situ formed ice into lower cloud layers. We present some early results for prescribed flow.