Polarimetric Method for Bright Band Detection

The detection and assessment of the bright band associated with the atmospheric melting layer is important for accurate hydrometeor classification and rainfall estimation. Knowledge of the location of the melting layer helps to distinguish liquid and frozen hydrometeors and to delineate regions where radar rainfall estimates are potentially biased due to contamination from frozen particles aloft. The suggested polarimetric method for bright band detection is based on combined use of Z, ZDR, and ρHV. Radial dependencies of these radar variables at elevation angles between 4.5˚ and 8.7˚ are used to estimate the height of the top and bottom of the melting layer.

The suggested method was tested on several cases collected during JPOLE. Performance of the method has been validated using available soundings. Results of automatic hydrometeor classification (contingent on the accurate assessment of the melting layer) are illustrated for several cases.