Characteristics of bright band detected by the TRMM precipitation radar

摘要

Detection of the bright band (BB) is carried out in 2A23, which is one of the TRMM Precipitation Radar (PR) standard algorithms. Though BB shows up rather clearly in the TRMM PR data near nadir directions, the observed BB smears as the antenna scan angle, defined as the off nadir angle of the radar beam, increases. Because of this smearing of BB and of other reasons, not all the BBs are detected by 2A23. Statistics of 2A23 show that BB is detected in about 40% of stratiform precipitation. What remains to be made in 2A23 includes the determination of the width of BB, which is challenging because we have to deal with the smeared BB profiles. Definition of the width of BB itself also is an issue. This paper examines the statistical range profiles of BB, which may give us some hints how to define the width of BB observed by the TRMM PR. The width of BB, obtained for the statistically averaged BB profiles, becomes larger as the intensity of BB increases; this result is consistent with those reported in the literature.