中文摘要：

利用OTT激光雨滴谱仪观测的南京地区2014—2016年共六场降雪粒子谱资料,按仪器记录的降水类型将资料分为雨夹雪、小雪、中雪,利用Gamma和M—P函数对粒子的尺度谱进行拟合,拟合参量由阶矩法求出。线性拟合得出降雪粒子末速度的V—D曲线,并与经验曲线进行对比分析;μ、λ关系由拟合所得二项式表示。结果表明：南京地区降雪尺度谱分布更接近于Gamma分布;小雪、中雪粒子的下落末速度同粒子直径变化无较大关联,降雪粒子以湿雪为主;雨夹雪很好地满足μ、λ二项式关系,小雪和中雪的μ、λ二项式关系相对更差,利用此关系简化Gamma函数进行遥感反演降水参量时,对于不同凝结状态的降雪需采取不同的μ、λ函数关系来表示。

英文摘要：

Snow particle spectrum data from six snowfall events in Nanjing area during 2014-2016 were obtained by laser spectrometer.The data were divided into three types based on the records：the sleet,the light snow and the moderate snow.Gamma and M-Pfunctions were introduced to describe the snow size distribution,and the fitting parameters were calculated with order moment method.The V-D curves for snow which obtained by linear fitting were compared with the empirical relationships.The binomial function was introduced to study the relationship betweenμandλ.Results showed that the snow particle size distribution was closer to Gamma distribution.No significant change was found between the fall-velocity and size to of the light snow and moderate snow,and snow particles mainly in wet snow.The sleet had a better binomial function relationship betweenμandλthan light snow and moderate snow.Differentμ,λrelationships should be considered based on the degree of condensation during the process of retrieving precipitation parameters by remote sensing by simplified Gamma function.