Polarimetric modelling of flare echoes, and comparisons with observations at C Band

Flares are radar artefacts that appear as ghost echoes behind nuclei of large reflectivity; from a theoretical point of view flares can be explained as a three-body scatter effect from a process that involves large hydrometeors (typically hail) and ground.

In this work a polarimetric model of flares is presented; the model has been developed on physical basis, i.e. it actually computed and integrates all the individual contributions of the three body-scattering mechanism; it is able to evaluate polarimetric signatures whichever the polarisation scheme used by the radar (H-V linear, slantwise linear, etc.), starting from a given profile of reflectivity Z.

Model's predictions are then compared with observations carried out with C-band polarimetric Doppler radars, operating in Italy and Germany. The predicted profiles are in good agreement with that measured by the radar, despite the relative simplicity of the model itself. This model will also prove to be a useful tool for the investigation of the sensitivity of the radar measurables to the variation of the electrical and geometrical parameters of the radar system.