Abstract:
Studying the vertical structure characteristics of raindrop size distributions (DSD) and their inversion features can help to promote our understanding of rainfall microphysical structures and improve the radar quantitative precipitation estimation. In this paper, the vertical structure characteristics of DSD and their inversion features corresponding to three rain types, namely convective rain (CR), stratiform rain (SR), and light rain (LR) in different seasons, are investigated based on the MRR data from March 2022 to May 2023 at Xiangyang national basic meteorological station. The results are as follows. (1) The bright band height of the rainfall clouds in spring of Xiangyang is mainly concentrated at about 4 km and the microphysical parameters of the precipitation suffer severe trembling here. (2) The vertical structures of DSD corresponding to different rain types are obviously different below the bright band. CR has the widest DSD spectra and highest number concentration. The evaporation and collision process co-exist as the rain drops, however, below 1 km the evaporation is dominant. SR showed relativity wide DSD spectra and high number concentration. Its evaporation process is more obvious than that of LR as the rain drops. Besides, there are also significant evaporation for small raindrops and fragment for some large raindrops. LR has a narrower spectra and smaller number concentration. At height 3~1 km, the collision process is obvious. At height below 1 km, large and medium raindrops fragment and small raindrops evaporate in large quantities. (3) For SR and CR, medium raindrops contribute most significantly to the surface rain rate. However, for LR, small raindrops contribute most significantly to the surface rain rate. Large raindrops make the least contribution for all cases. (4) The microphysical processes of LR and SR in summer and autumn are similar to some extent, yet the collision–coalescence processes is weaker than that in spring, while the microphysical change process of CR in spring and summer is stronger than that in autumn, and this shows the microphysical processes of different rainfall types have both seasonal similarities and differences.