摘要
为了研究低纬高原地区雨(雪)过程粒子微物理特征,利用布设在云南中部的一台Parsivel^2雨滴谱探测仪探测到的2015年12月16—17日雨(雪)过程粒子谱资料,对雨(雪)过程粒子微物理参量的演变特征、粒子数浓度、粒子谱及速度谱分布特征进行了分析.结果表明:此次降雨(雪)过程以降雪占主导地位.纯雨阶段粒子加权平均直径D_m为0.82 mm,纯雪阶段D_m仅为0.79 mm,雪粒子平均直径小于雨粒子平均直径;降水强度与粒子数浓度、雷达反射率之间具有较好的正相关性,粒子数浓度越大,雷达反射率越大,雨强越大,粒子直径与降雨强度没有明显的正相关特征;不同相态的粒子在同一直径档的下落速度差异较大,雨粒子下落速度与直径呈线性相关关系,下落速度靠近结霜一侧且在D_m<1.6 mm范围内,雪粒子则靠近未结霜一侧,粒子速度与粒子直径无明显线性相关关系;雨粒子直径较大、下落速度较快,表现出冻滴附着的显著特征,而雪粒子则以冰晶的单一增长为主要特征.
To better study microphysical characteristics during snowfall process in low latitude plateau area, drop size spectra were collected with Parsivel2 raindrop spectrum detector during the snowfall events in 16-17 December 2015 in center of Yunnan Province,the evolution characteristic of the microphysical parameters, particle number concentration, particle size and velocity distributions were investigated. It was found that ： snowfall dominated in the whole snowfall process ,the quality-weighted average particle diameter was 0.82 mm in pure rain period, the quality-weighted average particle diameter was only 0.79 mm in pure snow period, the average diame- ter of snow particle was less than which of rain particle.The precipitation intensity, number concentration and the radar reflectivity factor had positive linear correlations, particle number concentration was larger when the radar reflectivity and the precipitation intensity increased larger, particle diameter had no obvious positive correlation with rainfall intensity characteristics.The drop speed of particles for different phases of particles in the same diameter had significant differences. The drop speed of rain particle had linear correlation with particle diameter for rain particles and which was closed to the curves of frosting and within the particle diameter range of 1.6 ram, but the drop speed of snow particle was closed to the curves of no-frosting and which had no correlation with particle diameter.The diameter of rain particle was larger and the drop speed was faster,and the rain particle showed the significant attachment characteristic of frozen drops, but snow particle showed the main single ice -crystal growth characteristic.
出处
《云南大学学报（自然科学版）》
CAS
CSCD
北大核心
2017年第4期598-608,共11页
Journal of Yunnan University(Natural Sciences Edition)
基金
云南省科技厅应用基础研究计划面上项目(2015FB166)
云南省科技厅科技惠民计划项目(2016RA096)
云南省气象局2016年重点项目(RY201601)
关键词
雨(雪)过程
微物理参数
粒子谱
速度谱
rain-snow process
microphysical parameter
particle spectrum
velocity spectrum
作者简介
尹丽云（1979-），女，云南人，硕士，高级工程师，从事强对流灾害性天气和多普勒雷达资料的分析应用研究．E—mail：xiaoyuyly@163．com．
