Comparison Of Total Lightning Evolution And Polarimetric Radar Parameters In The Framework Of The BMBF klimazwei-Project RegioExAKT

Abstract

Within the BMBF klimazwei-project RegioExAKT the evolution of selected polarimetric radar data fields and the electrical activity of thunderstorms is analyzed with respect to the severe storm potential. Special focus is laid on the three-dimensional resolution of lightning incidents which allows for the discrimination of intracloud (IC) and cloud-to-ground (CG) events, too. The aim of the study is to interpret the temporal evolution of the observed quantities in terms of the underlying microphysical processes like e.g. rain, graupel or hail formation which have a hazardous potential and to assess how their history can be used to estimate the state and the further progress of a thunderstorm and its electrical activity. The temporal evolution of both the radar parameters and the lightning parameters will be shown in case studies for selected thunderstorms. Primary radar data were obtained from the C-band dual-polarization Doppler radar POLDIRAD of the DLR in Oberpfaffenhofen, Germany. Radar quantities such as reflectivity, linear depolarization index (LDR), differential reflectivity (ZDR) are used as well as a hydrometeor classification. Lightning data were provided by the European lightning detection network LINET. The network locates atmospheric discharges using the arrival time of the magnetic field of lightning induced electro-magnetic radiation in the VLF/LF regime. The system records the total lightning activity with lightning amplitudes, polarity and emission heights for IC strokes.