||Z - Zdr anti-correlation in an RHI scan through an ice cloud|
Differential reflectivity (Zdr) values are most positive in the outer, low-reflectivity regions of an echo layer where the scatterers are mainly horizontally-oriented planar ice crystals. In the higher reflectivity regions enclosed by the yellow 14 dBZ contour, the presence of quasi-spherical hydrometeors, such as clumps of aggregated ice crystals, lowers the Zdr to ~0 dB.
Photo credit: Patrick Kennedy
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