摘要
利用Parsivel观测的雨滴下落末速度和粒径资料,对雨滴谱进行精确的订正,并分别采用最小二乘法和阶矩法对订正后的滴谱进行M-P分布和Γ分布拟合,对比各种拟合结果计算的参量。结果表明,最小二乘法只对数密度拟合较好,而高阶量拟合严重失真;Γ分布比指数分布能够更好地拟合出对流云降水中雨滴数密度函数在雨滴谱两端的分布特征;在Γ分布下,Z-I关系主要受雨滴数密度影响,每次降水的Z-I关系可用平均谱参数计算,精度与常规的Z-I关系拟合方法相当。
Raindrop size distribution could be revised accurately from the raindrop terminal velocity and particle size information observed by Parsivel.Using the least square method and moment method to fit the revised raindrop for M-P distribution and Γ distribution,and comparing the parameters calculated by various fitting results,it was found that the least square method can only fit the number density well,however it is not good at high order parameter,which could be distorted severely,while the Γ distribution have the ascendancy which can fitting the distribution character of raindrop number density function at the both ends for the convective precipitation over exponential distribution.Effected by raindrop number density,Z-I law could be calculated by mean spectral parameter every time with equivalent accuracy of regular Z-I law.
出处
《安徽农业科学》
CAS
北大核心
2011年第10期5954-5957,5988,共5页
Journal of Anhui Agricultural Sciences
关键词
最小二乘法
阶矩法
M-P分布
分布
Least squares method
Moment method
M-P distribution
Γ distribution
