A Real-Time Bright Band Vertical Profile of Reflectivity Correction Using Multitilts of Reflectivity Data

Bright band (BB) is a layer of enhanced radar reflectivity because of hydrometeor melt and coalescence, which could cause a significant overestimation of radar quantitative precipitation estimation (QPE). Overestimation of QPE due to BB contamination may lead to false flood alarms. Vertical profile of reflectivity (VPR) correction is an effective means to reduce the overestimation of radar QPE caused by BB contamination. This study presents an improved BB apparent VPR correction algorithm (named IAVPR) using radar multitilts of reflectivity observations. The reflectivity observations in the same vertical layer are averaged, and the beam broadening effect is reduced. This optimization helps to correctly identify the BB top from the IAVPR, which further improves the BB bottom identification according to the symmetry of the BB vertical structure. The IAVPR algorithm improves upon an old AVPR algorithm that constructs a range profile of azimuthally averaged reflectivity observations in the BB-affected area (BBA) for each tilt and then applies the correction to the specific tilt based on the AVPR. The performance of the AVPR algorithm can be greatly affected by the spatial pattern of precipitation or terrain, where the IAVPR algorithm can consistently correct for BB contamination. A comprehensive evaluation is conducted using 13 precipitation events observed by six of China’s operational radars in different regions. The result shows that the IAVPR algorithm is more effective and robust for BB correction compared to the AVPR algorithm.