1 A dual-polarization radar hydrometeor classification algorithm for ...

599600601602603604605606607608609610Appendix 1: Radar data post processing.Co-polar correlation coefficient (! HV ) correction for noise (Bringi and Chandrasekar2001) and removal of Z dr bias was required for CASA data. Ground clutter was also removedfrom OU-PRIME and CSU-CHILL data. The specific differential phase (K DP ) was calculated foreach radar system using the Wang and Chandrasekar (2009) method. Many X- and C-bandobservations of non-zero backscatter differential phase (') in the melting layer confirmeddeparture from the Rayleigh scattering regime. Differential attenuation also occurs in ourdatasets within and beyond the melting layer for low radar elevation angles during periods ofheavy stratiform precipitation. When the radar beam intersects the bright band at a shallow angle,it becomes nearly oriented along the longest axis of large, water-coated aggregates. Attenuationcorrection for wet snowflakes is an ongoing topic of research (León et al. 2011) and therefore noattenuation correction was performed on these data.61129