摘要
为揭示华南地区强降水过程中降水粒子类型变化特征,选择2018年8月29日至31日华南后汛期一次典型强降水过程,首先使用ERA-Interim再分析资料和中国地区融合降水资料,分析了降水的天气形势并确定了降水的性质。之后使用华南地区S波段双偏振雷达资料观测量以及反演量,定义了对称性和非对称性降水的概念并对比分析了对称和非对称降水过程中降水粒子类型演变差异,基于最大降水合成法分析了不同类型降水粒子在降水开始、发展、消亡、结束阶段的演变情况。进一步分析了各类冰相和液相粒子的粒径、浓度与降水率的相关性。研究结果表明本次降水是受南海季风低压、低空急流、地形等多因素的影响形成的对流性降水。冰粒子数量较多的阶段降水维持时间长,冰粒子数量较少的阶段降水维持时间较短,冰粒子在不同降水阶段分布的多寡导致降水开始至达到峰值的时间与峰值发生后至降水结束的时间明显不同,即降水过程存在非对称性。在降水过程中有大量冰晶粒子下落碰并过冷水形成霰粒子,霰粒子从低密度向高密度转化预示着降水量的变化。降水开始阶段液相粒子粒径较小,数量较多,粒径和浓度同时增长,降水结束阶段液相粒子粒径较大,数量较少,粒径和浓度呈反相变化,表明降水末期粒子碰并过程更明显。
In order to reveal the evolution characteristics of hydrometeor types during the heavy precipitation process in South China,a typical heavy precipitation process in the post-flood season in South China was selected from August 29 to 31,2018.Firstly,the weather situation of precipitation was analyzed and the properties of precipitation was determined by using ERA-Interim reanalysis data and China regional integrated precipitation data.Then,the concepts of symmetric and asymmetric precipitation are defined by using S-band dual polarization radar observation and inversion data in South China,and the evolution differences of hydrometeor types in the process of symmetric and asymmetric precipitation are compared and analyzed.Based on the maximum precipitation synthesis method,the evolution of hydrometeor types in the beginning,development,weaken and ending stages of precipitation is analyzed.The correlation between the size and concentration of ice and liquid particles and the precipitation rate is analyzed.The results showed that the precipitation was a convective precipitation formed by the South China Sea monsoon low pressure,low-level jets,topography and other factors.The precipitation duration in the stage with more ice particles is longer than that with less ice particles.In different precipitation stages,the distribution of ice particles is significantly different from the beginning of the precipitation to the peak and from the time after the peak occurs to the end of the precipitation,that is,the precipitation process is asymmetry.Abundant ice crystals fall off and collide with supercooled water to form graupel,the transformation process of which from low density to high density indicates the evolution of precipitation.At the beginning of precipitation,the particle size of the liquid phase particles is smaller and the quantity is larger,the particle size and concentration increased simultaneously.However,at the end of precipitation,the particle size of the liquid particles is larger and the quantity is smaller
作者
宋文婷
陈江斌
李昀英
叶成志
SONG Wenting;CHEN Jiangbin;LI Yunying;YE Chengzhi(College of Meteorology and Oceanography,National University of Defense Technology,Changsha 410073,China;Hunan Meteorological Observatory,Changsha 410118,China)
出处
《自然灾害学报》
CSCD
北大核心
2021年第4期154-163,共10页
Journal of Natural Disasters
基金
国家自然科学基金(42075077)
国家重点研发计划项目(2018YFC1507604)
中国气象局小型业务能力建设项目
中国气象局气象预报业务关键技术发展专项(YBGJXM(2018)1A-10)。
关键词
强对流
华南地区
降水粒子类型
演变
strong convection
South China
hydrometeor types
evolution
