陕西渭北一次降雹过程的粒子谱特征分析  

Characteristics of Precipitation Particles in a Hailstorm Process in Weibei Area of Shaanxi Province

作　　者：岳治国[1] 梁谷[1] YUE Zhiguo;LIANG Gu(Office of Weather Modification of Shaanxi Province, Xi'an 710014, Shaanxi, China)

机构地区：[1]陕西省人工影响天气办公室,陕西西安710014

出　　处：《高原气象》2018年第6期1716-1724,共9页Plateau Meteorology

基　　金：国家重点研发计划项目(2016YFA0601704);陕西省自然科学基础研究计划项目(2010JM5002);陕西省气象局研究型业务重点科研项目(2012Z-13);公益性行业(气象)科研专项(GYHY201306060)

摘　　要：冰雹的大小、浓度和末速度等特征参量对冰雹云及人工防雹研究至关重要。基于Parsivel激光降水粒子谱仪观测的2013年5月22日陕西渭北一次降雹过程的资料,结合雷达反射率回波和自动站分钟降水量,分析了降雹过程中的雨强、雨量、最大冰雹直径、数浓度、谱分布及冰雹末速度等物理量随时间的演变。结果表明:(1)计算了降雹过程的平均粒子谱分布,并使用M-P分布对雨滴和冰雹分段进行了拟合。直径0. 3～4. 75 mm的雨滴谱拟合相关系数为0. 95,直径5. 5～11 mm的冰雹谱拟合相关系数为0. 99;(2)冰雹数浓度占总降水粒子数浓度的0. 3%,而冰雹对总降水量的贡献为37%;(3)降雹过程中,雨滴和冰雹数浓度同时增加或减小,冰雹分钟数浓度最大为5 m^(-3),雨滴分钟数浓度最大为1 423 m^(-3)。(4)国内首次现场观测了冰雹的末速度,使用实测值拟合得到了平均冰雹末速度与冰雹直径的经验公式,经验公式计算的冰雹末速度平均相对误差为2. 8%。It is very important for the study of hail cloud and its suppression to learn the characteristic parameters of hail such as number concentration, the maximum diameter, terminal velocity. Based on the data collected by Parsivel precipitation particle spectrometer in a hail process occurred on 22 May 2013 in Weibei area of Shaanxi Province, combing the data of radar reflectivity and minute precipitation data from the automatic station, the temporal evolution of physical parameters was analyzed that include the rainfall intensity, rainfall amount, maximum hail diameter, number concentration, spectral distribution and hail velocity. The results are shown as follows:(1)The average particle spectrum distributions of rain and hail were calculated for this hail process, and fitted by the Marshall-Palmer exponential distribution. The correlation coefficient of fitting is 0.95 for raindrop with diameter of 0.3~4.75 mm, and 0.99 for hail with diameter of 5.5~11 mm;(2) The number concentrations of hail are 0.3% of the total precipitation particles, and its precipitation accounts for 37% of the total precipitation;(3) During the hail process, the number concentration of raindrop and hail increases or decreases simultaneously. The maximum number concentrations of hail and raindrop are 5 m-3 and 1 423 m-3 in one minute, respectively;(4) This is the first time that the terminal velocity of hail was measured in situ in China. The empirical formula of the average hail velocity is obtained by fitting the measured terminal velocities with the hail diameter, and its relative error is 2.8% in respect to the measured average terminal velocity of hail. This study will be a firm foundation for the further learning the features of hailstorm and the effect of artificial hail suppression in this area, and will be a good reference for the development of explicit cloud physics scheme of numerical model.

关 键 词：Parsivel 降水粒子谱仪 冰雹谱 M-P分布 冰雹末速度 

分 类 号：P426.64[天文地球—大气科学及气象学]