Augmenting the German weather radar network with vertically pointing cloud radars: implications of resolution and attenuation

Abstract. A beam-aware columnar vertical profile (BA-CVP) methodology that incorporates data of the national German operational radar network with the aim of augmenting vertically pointing cloud radars is introduced. The method uses polarimetric radar data collected in plan position indicator (PPI) scans of multiple operational radars and considers the contributions of each operational radar in a beam-aware manner. The results of the method are paired with measurements of a vertically pointing cloud radar located in range of the operational radars and compared to measurements of dedicated scanning radars collected in range height indicator (RHI) scans for two different case studies. The combination of side-looking operational radars in the BA-CVP format with a vertically pointing cloud radar allows the simultaneous exploitation of polarimetric multi-frequency observations including radar variables like the differential reflectivity, the dual-wavelength ratio, Doppler fall speed and linear depolarisation ratio measurements to study the microphysical properties of hydrometeors while not having to rely on the availability of dedicated scanning radars. The extracted BA-CVPs based on operational data deliver good results with respect to resolving finer details in radar reflectivity and differential reflectivity when compared to measurements of dedicated radars. Usage of differential phase measurements is discussed as marker for high hydrometeor attenuation affecting the measurements of radars far from the point of interest. For future use of this method, the coverage of the national German operational radar network is studied and recommendations for locations with potential for additional vertically pointing cloud radars are pointed out.