Raindrop size distribution (RSD) is a crucial linkage between the precipitation characteristics and related microphysical processes. However, its representation in the numerical weather model still has significant uncertainties. In this study, by using the Weather Research and Forecasting (WRF) model with three widely-used bulk microphysics schemes: The Morrison, Thompson, and WRF double-moment 6-class (WDM6) microphysics schemes, the simulated RSD characteristics in the eyewall and spiral rainbands of Typhoon Lekima (2019) are evaluated against a dense disdrometer network observation. Verifications generally show the overestimated mass-weight mean diameter (D_m) but the underestimated normalized number concentration (N_w) by three microphysics schemes. In comparison with the other two schemes, the RSD characteristics simulated by the Thompson scheme are more consistent with the observation. Furthermore, simulations produced less and somewhat different RSD variability among the eyewall and rainbands than observations. From the outer rainband to the eyewall, the probability density function (PDF) curve of observed D_m shows a left-skewed distribution with a flatter shape and decreasing peakedness, whereas the simulations show a narrower and right-skewed PDF of D_m. The discrepancy between the model and observations is primarily attributed to more intense tendencies of D_m growth and N_w reduction in simulations during raindrops descend to the ground. Examinations of vertical profiles for rain-related microphysical processes indicate that this discrepancy likely originates with the over-predicted collision-coalescence process.

雨滴粒径分布（RSD）是降水特征与相关微物理过程之间的重要联系。然而，它在数值天气模型中的表示仍然存在很大的不确定性。在这项研究中，通过使用天气研究和预报 (WRF) 模型和三种广泛使用的体微物理方案：Morrison、Thompson 和 WRF 双矩 6 类 (WDM6) 微物理方案，模拟了眼壁中的 RSD 特征台风 Lekima（2019 年）的螺旋雨带和螺旋雨带根据密集的测距仪网络观测进行评估。验证通常显示高估的质量重量平均直径 ( D _m ) 但低估的归一化数浓度 ( N _w) 通过三个微物理方案。与其他两种方案相比，Thompson 方案模拟的 RSD 特征与观测结果更加一致。此外，与观测相比，模拟产生的眼墙和雨带之间的 RSD 变化较少且略有不同。从外雨带到眼墙，观测到的D _m的概率密度函数 (PDF) 曲线显示出左偏分布，形状更平坦，峰度降低，而模拟显示D _m的 PDF 更窄且右偏。模型和观测值之间的差异主要归因于D _m增长和N _{w的更强烈趋势}雨滴落到地面时的模拟减少。对与降雨相关的微物理过程的垂直剖面的检查表明，这种差异可能源于过度预测的碰撞-聚结过程。