【摘要】 为深入了解呼和浩特地区降雨和降雪过程中降水粒子谱的分布特征,利用Parsivel观测数据并结合常规观测资料,对2017—2019年发生在呼和浩特地区的8次降雨过程和10次降雪过程的降水粒子谱进行分析。结果表明:雨滴谱和雪花谱都比较符合Gamma分布,平均降雪谱的峰值直径、峰值浓度以及最大直径均大于平均雨滴谱,降水强度相近时,降雪个例的粒子数浓度和尺度参数均大于降雨个例;Gamma拟合的形状因子（μ）和斜率参数（A）在降雨和降雪过程中均满足二项式关系,但雪花尺度的变化范围较大导致降雪的μ-A拟合效果略差;雪花的下落速度小于雨滴的下落速度,降雨过程中雨滴的下落速度多集中于2～5 m·s^-1,而降雪过程雪花的下落速度多集中于0.5～2 m·s^-1,呼和浩特地区降雪的雪花下落速度更接近于未结凇或干雪的情况。更多还原

【Abstract】 In order to understand the characteristics of particle size distribution during rain and snow processes,ground-based measurements of particle spectrum using a Parsivel disdrometer were compared among samples obtained in 8 rain processes and 10 snow processes in Hohhot from 2017 to 2019.The results show that both the size distributions of raindrop and snowflake are in good agreement with the Gamma distribution.The spectrum width,peak concentration and corresponding diameter of snow spectrum are larger than those of raindrop spectrum,and the snow cases always have larger particle concentration and scale parameters compared to the rain cases when the precipitation intensities are similar.The parametersμ and A of Gamma function correspond to the shape and slope of the spectrum,and they satisfy binomial function relationship during both rainfall and snowfall processes,but the fitting effect is poor during snowfall because of the too large-scale range of snowflake.The particle velocity is smaller for snowflake than for raindrop.The falling velocity of raindrops is mostly concentrated at 2-5 m·s^-1,while the falling velocity of snowflake is mostly concentrated at 0.5-2 m·s^-1,and closer to the speed curve of unfrozen snowflake in comparison.更多还原