Midlatitude Ice Clouds

Routine deployment of the COBALD sensor together with high quality water vapor measurements is strongly supported by the MeteoSwiss radio sounding station in Payerne and the DWD Lindenberg Meteorological Observatory (external pageMOL-RAO). Both facilities are part of the GCOS Reference Upper-Air Network (external pageGRUAN) and the balloon soundings are complemented by ground based external pageLIDAR measurements.

This measurement setup enables us to match LIDAR and radiosonde humidity and backscatter measurements and use these as constraints for subsequent Lagrangian air parcel modeling. The modeling is performed with the Zurich Optical and Microphysical Model (ZOMM) developed in our group, driven by Lagrangian trajectories calculated from the numerical weather prediction model COSMO. Reconciling observations with modeling results allows us to improve our understanding of midlatitude ice cloud characteristics and processes by reducing uncertainties in the type of nucleation involved, as well as in the number density, size, growth habit and sedimentation speed of the ice particles, which are crucial properties governing cloud lifecycle and radiative properties.