Characteristics of Raindrop Size Distribution in Different Areas of Southeastern Tibetan Plateau

Based on the raindrop size distribution (RSD) data obtained in the Shiqu, Xinlong and Luding sites of the southeastern Tibet Plateau from May to August 2019, the raindrop spectrum characteristics of different rainfall intensities and different precipitation types in three regions were compared and analyzed. The relationships between reflectivity (Z) and rain rate (R), as well as the shape parameter (\mu) and the slope parameter (\Lambda)were determined, the difference of raindrop spectrum between the southeast of Tibetan Plateau and other regions in China was discussed. The results show that the number concentration increased with the increasing rain intensity. A small amount of larger raindrops could be produced under the same rain intensity in Shiqu, and the number concentration of medium and large raindrops from large to small was Shiqu, Xinlong, Luding. The Gamma model had a good simulation effect on the raindrop spectrum of stratiform cloud and convective cloud in the southeast of Tibetan Plateau. The raindrop spectrum of convective cloud was significantly wider and the slope was smaller than that of stratiform cloud. The Z–R relationship of stratiform precipitation was basically consistent, while the corresponding Z values under the same R in convective precipitation were Shiqu, Xinlong, Luding in descending order. And the \mu – \Lambda relationship was also basically the same, which fit well with the binomial relationship. The average N_w of stratiform and convective precipitation in the three areas was smaller than that in other areas of China, and the average D_m of convective precipitation in Shiqu was the largest, but the average N_w was the smallest.