Clouds are important features of the atmosphere, determining the energy budget by interacting with incoming solar radiation and outgoing thermal radiation. For pure ice clouds, the net impact of the different radiative effects is still unknown, and there is no generally accepted theory of clouds in terms of a closed system of partial differential equations or similar.

In this talk, I will present a simple but physically consistent ice cloud model which is a 3D nonlinear ODE system (depending on several parameters). This model constitutes a nonlinear oscillator with two Hopf bifurcations in the relevant parameter regime. Apart from the equilibrium points and bifurcations, limits cycles and scaling behaviours of the system for varying parameters can be determined numerically. Finally, the model shows very good agreement with measurement data, indicating that the main physics is captured and such a simple model might be a helpful tool for investigating ice clouds.

This joint work with Peter Spichtinger.