| Summary: | Bright band (BB) characteristics obtained via dual-polarization weather radars elucidate thermodynamic and microphysical processes within precipitation systems. This study identified BB using morphological features from quasi-vertical profiles (QVPs) of polarimetric observations, and their geometric, thermodynamic, and polarimetric characteristics were statistically examined using nine operational S-band weather radars in South Korea. For comparable analysis among weather radars in the network, the calibration biases in reflectivity (Z<sub>H</sub>) and differential reflectivity (Z<sub>DR</sub>) were corrected based on self-consistency. The cross-correlation coefficient (ρ<sub>HV</sub>) bias in the weak echo regions was corrected using the signal-to-noise ratio (SNR). First, we analyzed the heights of BB<sub>PEAK</sub> derived from the Z<sub>H</sub> as a function of season and compared the heights of BB<sub>PEAK</sub> derived from the Z<sub>H</sub>, Z<sub>DR</sub>, and ρ<sub>HV</sub>. The heights of BB<sub>PEAK</sub> were highest in the summer season when the surface temperature was high. However, they showed distinct differences depending on the location (e.g., latitude) within the radar network, even in the same season. The height where the size of melting particles was at a maximum (BB<sub>PEAK</sub> from the Z<sub>H</sub>) was above that where the oblateness of these particles maximized (BB<sub>PEAK</sub> from Z<sub>DR</sub>). The height at which the inhomogeneity of hydometeors was at maximum (BB<sub>PEAK</sub> from the ρ<sub>HV</sub>) was also below that of BB<sub>PEAK</sub> from the Z<sub>H</sub>. Second, BB thickness and relative position of BB<sub>PEAK</sub> were investigated to characterize the geometric structure of the BBs. The BB thickness increased as the Z<sub>H</sub> at BB<sub>BOTTOM</sub> increased, which indicated that large snowflakes melt more slowly than small snowflakes. The geometrical structure of the BBs was asymmetric, since the melting particles spent more time forming the thin shell of meltwater around them, and they rapidly collapsed to form a raindrop at the final stage of melting. Third, the heights of BB<sub>TOP</sub>, BB<sub>PEAK</sub>, and BB<sub>BOTTOM</sub> were compared with the zero-isotherm heights. The dry-temperature zero-isotherm heights were between BB<sub>TOP</sub> and BB<sub>BOTTOM</sub>, while the wet-bulb temperature zero-isotherm heights were close to the height of BB<sub>PEAK</sub>. Finally, we examined the polarimetric observations to understand the involved microphysical processes. The correlation among Z<sub>H</sub> at BB<sub>TOP</sub>, BB<sub>PEAK</sub>, and BB<sub>BOTTOM</sub> was high (>0.94), and the Z<sub>DR</sub> at BB<sub>BOTTOM</sub> was high when the BB’s intensity was strong. This proved that the size and concentration of snowflakes above the BB influence the size and concentration of raindrops below the BB. There was no depression in the ρ<sub>HV</sub> for a weak BB. Finally, the mean profile of the Z<sub>H</sub> and Z<sub>DR</sub> depended on the Z<sub>H</sub> at BB<sub>BOTTOM</sub>. In conclusion, the growth process of snowflakes above the BB controls polarimetric observations of BB.
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