河南豫北一次降雹过程的粒子谱分布特征分析

Particle Distribution Characteristics of a Hailstorm Process in Northern Henan

利用新乡市辉县国家自动气象站布设的DSG5型降水现象仪的观测数据,对2021年5月20日新乡市的一次降雹过程进行分析。结果表明:①本次降雹过程雨滴占了绝大部分,达到了99.68%,而冰雹仅占降水总粒子数的0.32%,最大冰雹直径达到14 mm,冰雹数浓度和雨滴数浓度变化具有一致性;②降雹主要分为两个高峰期,分别在16:49附近和16:55附近,两个时刻的瞬时粒子谱均为单峰分布,峰值直径为0.6 mm;③Gamma最小二乘法、阶矩法对整个过程实际粒子谱分布的拟合效果都比较好,整体上曲线吻合度较高,M-P拟合冰雹谱的相关系数为0.96,冰雹谱满足指数分布;④实际降雹过程中,粒子下落末速度差异较大,冰雹的动能通量在直径10 mm时处达到峰值,近乎中等大小的冰雹的动能通量最大。

Based on the observation data of DSG5 precipitation weather phenomenon instruments in Huixian National Observatory of Xinxiang City,a hail process in Xinxiang City on May 20,2021 was analyzed.The results showed that:①In this hail process,raindrops accounted for the vast majority,reaching 99.68%,while hail only accounted for 0.32%of the total precipitation particle number,and the maximum hail diameter reached 14 mm.The variation of hail number concentration and raindrop number concentration was consistent;②The hail process is mainly divided into two peaks,at 16:49 and 16:55,respectively.The instantaneous particle spectra at both moments are unimodal distribution,and the peak diameter is 0.6 mm;③The least square method and the moment method of Gamma distribution have good fitting effect on the actual particle spectrum distribution in the whole process,and the overall curve is highly consistent.The correlation coefficient of M-P fitting hail spectrum is 0.96,and the hail spectrum satisfies exponential distribution.④Fitting the final falling velocity of particles.The discontinuous distribution of hail particles appears at the position of maximum hail particles.⑤the deference of falling velocity is the kinetic energy flux of hailstones reaches its peak at 10mm,and the kinetic energy flux of hailstones is the largest nearly medium size.