2016年5月6日重庆万盛短时强降水雨滴谱特征分析

利用激光雨滴谱仪对2015年5月6日四川盆地东南部与云贵高原交界处的重庆万盛地区一次由地形强迫抬升形成的短时强降水过程进行观测，分析了雨滴谱相关特征值变化情况。结果表明：雨滴谱能够较好的反映本次过程雨量的细节，谱型能够较好地反映对流的生消过程；雨滴的数浓度并不是影响雨强的决定性因素，粒子大小对雨强的贡献同样很重要；大粒子虽然很少，但对雨强的贡献远大于小粒子（如大于3mm的粒子在雷达反射率因子中起主要贡献，达到97%）；强烈的对流使大粒子在下落过程中破碎形成小粒子；三参数Gamma分布能够较好的拟合本次降水过程雨滴谱分布；小粒子的速度谱大于实验典型值，与大粒子在下落过程中破碎形成小粒子有关。

Analysis on raindrop spectrum during a short-time strong precipitation on 6, May 2015 in Wansheng

By using data from Parsivel precipitation particle spectrometer, the raindrop spectrum characteristics of a short-time strong precipitation occurred in Wansheng of Chongqing in the junction of southeast Sichuan basin and Yunnan-Guizhou plateau on May 6 2015 are analyzed. The results show that the raindrop spectrum can better reflect the details of rainfall in this process, and the spectrum pattern can better reflect the process of convection. The number concentration of raindrops is not the decisive factor of rain intensity. Although there are few large particles, their contribution to rain intensity is much greater than that of small particles (for example, particles larger than 3mm play a major contribution in radar reflectivity factor, reaching 97%). Strong convection causes large particles to break up into small ones during their fall. The three-parameter Gamma distribution can well fit the distribution of raindrop spectrum in this precipitation process. The velocity spectrum of small particles is larger than the typical value of experiment, which is related to the formation of small particles in the falling process of large particles.