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投稿时间：2015-09-29 修订日期：2016-01-09
投稿时间：2015-09-29 修订日期：2016-01-09
中文摘要: 利用2014年8月4—23日山西忻州OTT Parsivel 二代激光雨滴谱仪获得的雨滴谱资料，研究了估算雨滴谱Γ分布三参数的阶矩法。把降水云分为层状云、积状云、积层混合云三种，采用最小二乘法和阶矩法估算雨滴谱，并在现有阶矩法的研究上，提出一种新矩量组合M036与其他矩量一起分1 min、5 min平均和5 min滑动平均估算雨滴谱样本的均方根误差和误差谱分布，并进行比较，同时研究了不同降水云雨滴谱三参数随雨强R的变化关系。结果表明：阶矩法估算Γ分布雨滴谱，M036矩量组合代表雨滴数浓度、液态水含量和雷达反射率因子，三个物理量计算方便，物理意义清晰,实际应用中如能通过探测手段获得三个矩量，就能反演得到云中雨滴谱。阶矩法中M036估算最好；估算三种不同时间雨滴谱样本的均方根误差平均值，M036误差最小；分析三种不同时间雨滴谱样本的均方根误差谱分布，M036谱宽最窄，误差集中；估算三种降水云雨滴谱三参数随雨强R的增大而减少；拟合雨滴谱Γ分布三参数N0、μ、λ满足二项式分布且相关系数较好。
中文关键词: 雨滴谱，Γ分布，三参数，阶矩法
Abstract:Using the rain drop size distribution (DSD) data obtained from OTT Parsivel Ⅱlaser optical disdrometer in 4-23 August 2014 in Xinzhou, Shanxi Province, the moments method for estimating Gamma DSD parameters is studied in this paper. The precipitation clouds are divided into three categories: stratiform, cumuliform and stratiform mixed with cumuliform. Comparing the observed and estimated DSD data in 1 min, 5 min average and moving 5 min average, root mean square error (RMSE) and error distribution of DSD are computed with the method of least square and moments. A new method of moments is put forward involving M0, M3 and M6 which respectively represent the moments of raindrop number concentration, liquid water content and radar reflectivity. The analysis shows that using moments to estimate rain DSD, the M036 (M0, M3 and M6) is the best among the moment methods because the averaged RMSE in 1 min, 5 min average and moving 5 min average is minimum and the error distribution is concentrated. The parameters of DSD estimated from three kind precipitation clouds decrease with the increase of rainfall intensity R. The fitting DSD parameters (N0, μ, λ) satisfy binomial distribution and their correlation coefficient is good.
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基金项目:国家重大科学研究计划（2013CB955802）和公益性行业（气象）科研专项（GYHY201206025）共同资助
引用文本：
熊飞麟,周毓荃,2016.估算雨滴谱Γ分布三参数的阶矩法研究[J].气象,42(7):777-789.
XIONG Feilin,ZHOU Yuquan,2016.Study of Moment Methods in Estimating Three Parameters of Gamma Raindrop Size Distribution[J].Meteor Mon,42(7):777-789.
熊飞麟,周毓荃,2016.估算雨滴谱Γ分布三参数的阶矩法研究[J].气象,42(7):777-789.
XIONG Feilin,ZHOU Yuquan,2016.Study of Moment Methods in Estimating Three Parameters of Gamma Raindrop Size Distribution[J].Meteor Mon,42(7):777-789.