摘要
结合2014年7月30—31日滁州地区一次强飑线降水过程的地面雨滴谱观测资料,构建了雨滴谱模型参数与雷达反演降水中常用的Z=ARb中系数A和指数b之间的相关关系,得出了适用于此次飑线降水的新Z-R关系。通过与雨滴谱观测结果和参考关系(Z=300R1.40)反演结果进行对比,对新的Z-R关系反演降水效果进行了评估。结果表明:利用降水强度对粒子数浓度和尺度标准化处理后,Gamma分布可以较好地描述此次飑线降水的雨滴谱分布。Z-R关系随着降水雨滴谱的变化而变化,指数b与不同阶数矩量随雨强的变化有关,系数A与雨滴谱的谱型分布有关。此次飑线降水Z-R关系的指数b=1.37;雨滴谱在Gamma分布下,系数A=340.91,在指数分布下,系数A=371.95。新的Z-R关系和参考关系反演的降水强度较实际观测值均偏小,但新的Z-R关系提高了此次飑线降水的总体估计效果。
Based on the ground-based raindrop spectra data of a squall line with heavy rain occurred in Chuzhou, Anhui province during 30-31 July 2014, the new parameters A and b in Z-R relationship, which is usually used in radar rainfall estimation, are obtained. Based on the comparative study of the estimation results from the new Z-R relationships with the observation data, the effects of the inversed precipitation from the new Z-R relationship has been evaluated. The results show that the exponent b is connected to the variation of different orders of moment with rainfall duration. The proper exponent b for this squall line process is 1.37. The parameter A is connected with the raindrop size distribution. A is 340.91 under the Gamma distribution and is 371.95 under exponential distribution. Although the estimated rainfall durations from the new and the standard Z-R relations are smaller than the observed one, the new Z-R relations get a better performance.
出处
《气象与减灾研究》
2015年第4期46-53,共8页
Meteorology and Disaster Reduction Research
基金
国家自然科学基金项目(编号:41375106)
关键词
雨滴谱分布
阶矩法
Z-R关系
降水评估
raindrop size distribution
moment method
Z-R relationship
quantitative precipitation estimation.
