山东三类降水云雨滴谱分布特征的观测研究

利用激光雨滴谱仪2009年8月—2010年10月观测获取的滴谱资料,分析了山东省三类云降水雨滴微结构参量特征及滴谱随降水过程的演变特征。按照降水云系不同分别对各微物理参量进行比较,结果表明,各值由大到小排序依次均为积雨云、混合云和层状云。三类云降水过程中雨强与雨滴数浓度和最大直径间存在较好的相关关系;层状云和混合云降水以直径小于2 mm的雨滴为主,而积雨云降水以1~3 mm的雨滴对雨强贡献最大。层状云降水雨滴谱很窄,呈单峰或双峰型;积雨云降水雨滴谱宽,在大滴端呈多峰结构;混合云降水谱宽介于前两者之间。另外,统计得到该地区三类云降水的Z-I关系式,为雷达定量测量降水提供了一定的参考。

A study on the distribution of raindrop size in three types of precipitation in Shandong Province

By using the data observed by a laser raindrop spectrometer from August 2009 to October 2010,the microphysical characteristics and raindrop size distributions varying with time in three kinds of precipitation in Shandong were analyzed.According to different precipitation clouds,the values of microphysical characteristics were compared.The results show that the values in convective cloud precipitation,mixed-cloud precipitation and stratiform cloud present a decreasing trend.The precipitation intensity is consistent with the density of raindrops and the maximum diameter in all three kinds of precipitation.The raindrops of diameter at less than 2 mm play the most important role in precipitation brought by stratiform cloud and mixed-cloud,while those of diameters between 1 mm and 3 mm contribute the most to the rain intensity in cumulus precipitation.The distribution of raindrop size in stratiform precipitation is very narrow,which is mainly of single-peak or double-peak;for cumulus precipitation,it has a wide spectrum with a multi-peak structure in great drops;the spectral width in mixed-cloud precipitation is between the aformentioned two.In addition,the Z-I relation formulas in the three different precipitation clouds is analyzed,which can be used in the quantitative measurement of rainfall.