Precipitation microphysics over the Tibetan Plateau (TP) remain insufficiently understood, due to the lack of observations and studies. This paper presents a comprehensive investigation of the raindrop size distribution (DSD) for rainfall that happened on the eastern slope of TP in summer. DSD differences between different rain types and under different rain rates are investigated. Confidential empirical relationships between the gamma shape and slope parameters, and between reflectivity and rain rate are proposed. DSD properties in this area are also compared with those in other areas. The results indicate that the stratiform and convective rains contribute to different rain duration and amount, with diverse rainfall macro- and microphysical properties. The rain spectra of two rain types can become broader with higher concentrations as the rain rate increases. DSDs in this area are different to those in other areas. The stratiform DSD is narrower than that in the non-plateau area. The two rain types of this area both have higher number concentrations for 0.437–1.625 mm raindrops than those of the mid-TP. The relationships of shape–slope parameters and reflectivity–rain rate in this area are also different from those in other areas. The rain spectra in this area can produce a larger slope parameter under the same shape parameter than in the mid-TP. The convective rain can produce a smaller rain rate under the same reflectivity. The accuracy proposed reflectivity–rain rate relationship in application to quantitative rainfall estimation is also discussed. The results show that the relationship has an excellent performance when the rain rate exceeds 1 mm h^-1.

中文翻译：

---

夏季青藏高原东坡雨滴大小分布特征

由于缺乏观测和研究，对青藏高原（TP）的降水微物理学仍知之甚少。本文对夏季TP东坡发生的降雨的雨滴大小分布（DSD）进行了全面调查。研究了不同降雨类型之间以及不同降雨率下的DSD差异。提出了伽马形状和斜率参数之间以及反射率和降雨率之间的机密经验关系。该区域的DSD属性也与其他区域的DSD属性进行了比较。结果表明，层状雨和对流雨对降雨持续时间和雨量的影响不同，降雨的宏观和微观物理特性各不相同。随着降雨率的增加，两种降雨类型的降雨谱可以随着浓度的升高而变得更宽。该区域的DSD与其他区域的DSD不同。分层DSD比非高原地区窄。该地区的两种降雨类型在0.437–1.625 mm的雨滴中均具有比中部中期更高的降雨浓度。该区域的形状-坡度参数与反射率-降雨率之间的关系也与其他区域不同。在相同形状参数下，该区域的雨谱可以比中TP产生更大的斜率参数。在相同的反射率下，对流雨可以产生较小的降雨率。还讨论了反射率与降雨率之间关系的准确性，该关系在降雨定量估算中的应用。^-1。