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Radar and lightning detection

VPR correction

A major source of errors affecting radar precipitation estimates is produced by vertical variations of reflectivity caused by growth, melting, and evaporation of precipitation. Many methods have been proposed in the literature to correct for non-uniform vertical profiles of reflectivity (VPR). A common approach consists in estimating the shape of the VPR and using it to extrapolate radar reflectivity measured aloft to ground level.

At mid-latitudes, the bright band effect caused by the melting of snow precipitation under the freezing level is responsible for significant vertical variations of the reflectivity as illustrated below:

 

Bright band effect: melting snow produces enhanced reflectivity values.

Bright band effect

5-min image (PCAPPI-1500m) affected by a bright band effect

24h precipitation accumulation affect by a bright band effect

Contact person for this topic: Laurent Delobbe