气象学报2018，Vol.76Issue(1)：148-159,12.DOI:10.11676/qxxb2017.085
北京冬季降水粒子谱及其下落速度的分布特征
Distributions of particle size and fall velocities of winter precipitation in Beijing
摘要
Abstract
Joint size and fall velocity distributions of particles were measured with a Particle Size and Velocity (PARSIVEL) precipitation disdrometer in a field experiment conducted during winter at Haituo Mountain in Beijing.The microscope camera and cloud radar were also used during the same period.Microphysical properties and fall velocities of super cooled liquid rain,graupel,snow and mixed-phase precipitation particles are compared.The major results are as follows.(1) The cloud of graupel precipitation contains more liquid water and the cloud top is the highest;LDR (linear depolarization ratio) is the smallest in the bottom of cloud among the three types of precipitation,which means that particles are nearly spherical.The cloud of snow precipitation contains less liquid water and the top is the lowest.The reflectivity and LDR values of mixed-phase precipitation are between that of the other two types of precipitation.(2) Examination of the particle fall velocity reveals that the liquid raindrop,snow crystal and graupel fall velocities are mainly determined by theoretical terminal velocities,and distribute symmetrically along the theoretical terminal velocity lines due to updrafts,downdrafts and turbulences in clouds.Based on this result,we can distinguish the particle type for a period.(3) The spread of particle velocity is larger for solid particles than for liquid particles.The microphysics processes are complex in cold clouds that produce many types of particle shape with different terminal velocities.Moreover,the turbulence,riming,breakup and coalescence likely cause the large spread of particles velocity.(4) The mean diameter and dispersion are the largest in snow and the smallest in rain.The concentration is the largest in mixed-phase precipitation and the smallest in rain.The concentration,mean diameter and dispersion of the four types of precipitation all increase with precipitation rate.关键词
冬季降水/粒子下落速度/粒子形态Key words
Winter precipitation/Particle velocity/Particle shape分类
天文与地球科学引用本文复制引用
贾星灿,马新成,毕凯,陈羿辰,田平,高扬,刘香娥,何晖..北京冬季降水粒子谱及其下落速度的分布特征[J].气象学报,2018,76(1):148-159,12.基金项目
国家自然科学基金项目(41505119、41675138)、国家重点研发计划项目(2017YFC0209600)、北京市自然科学基金资助项目(8172023)、中国气象局气溶胶与云降水重点开放实验室开放课题(KDW1403)、北京市科技计划项目(D171100000717001). （41505119、41675138）
