We utilize the fact that snowflakes transition at microwave frequencies from the Rayleigh to the Mie scattering regime. If we combine multiple radar frequencies, we can thus infer the size and density of the snow particles inside the cloud, which are key quantities to constrain the model simulations.
Radar Polarimetry and Doppler spectra
Modern cloud radars can provide much more than just the “strength” of the radar echo. They can tell us how fast the particles fall inside the cloud and even how their overall shape looks like, e.g. whether they are ice needles or plates or relatively round snowflakes or graupel. These capabilities need lots of expertise to properly interpret them but also provide a new dimension of observations which can be used to further understand the processes happening in the cloud.
1D Lagrangian Modelling
In order to utilize the information from our measurements to improve numerical weather prediction models, we investigate the implementation of these processes in much more detail using so-called super-particles in a Lagrangian model. This approach is very new and showed large potential to better understand the actual physical process and the history of particles while undergoing different modification along their way through the cloud (e.g., growth, aggregation, sublimations, etc.). This detailed understanding is then used to improve parametrizations in larger scale models.