摘要
利用常规高空、地面观测资料和多普勒雷达资料,采用中尺度数值模式(WRF),对发生在浙江省的一次冰雹天气过程进行了综合分析和数值模拟,从气流、温度结构以及雹云中的各类微观物理量的时空变化分析了此次冰雹过程的宏微观演变特征及形成机制。结果表明,该次强对流天气是在大尺度动力不稳定、热力不稳定的环境场和上干下湿的不稳定层结下发生发展的,边界层中尺度辐合线作为抬升触发机制释放不稳定能量。模式模拟得到的地面累积降水和雷达反射率因子与实况基本符合;模拟的水汽辐合区、能量锋区以及雷达反射率因子高值区接近辐合线。模拟的雹云属多单体风暴,具有明显的合并发展特征;霰(雹胚)通过雪晶的碰冻过程及过冷雨滴冻结产生,后碰并增长转化形成冰雹,冰雹通过碰冻过冷水滴和碰撞收集冰雪晶快速增长,最终降落至地面。其中,雹云内的过冷雨水累积带对霰及雹的产生及增长至关重要。
A severe convective hailstorm in Zhejiang province is investigated using upper-level and surface data of conventional observation, Doppler radar and WRF （Weather Research and Forecast） model simulations for its flow and temperature structure and temporal and spatial variation of variant microphysical quantities to under- stand the evolution of hail clouds. It is shown that the deep convective weather occurred in a large-scale envi-ronment field of dynamic and thermodynamic instability and a very unstable stratification, and a mesoscale con-vergence line acted as an uplifting mechanism to trigger convective instability energy. According to the modeling results, the simulated ground accumulated precipitation and maximum reflectivity are in accordance with the ob- served data, and the position of a simulated moisture convergence zone, an energy frontal zone and high reflec- tivity area are close to the convergence line. Being a multi-cell storm, the simulated hailstorm shows character- istics of combination and development. Snow crystals growing by accretion of cloud water and ice and frozen drops serve as graupel （hail embryos） , and then, this process may become large enough to be reclassified as hail. Hail grows by accretion of super-cooled raindrops, ice and snow crystals and falls to ground eventually. An accumulation zone of super-cooled raindrops is of great importance to the production and growth of graupel and hail.
出处
《热带气象学报》
CSCD
北大核心
2016年第4期546-557,共12页
Journal of Tropical Meteorology
基金
国家自然科学基金面上项目(41375137)
江苏省自然科学基金(BK2012860)
江苏省气象科学研究所北极阁基金(BJG201304)
气象灾害省部共建教育部重点实验室(南京信息工程大学)开放课题(KLME1205)共同资助
关键词
强对流天气
冰雹
云物理结构
云物理机制
WRF
数值模拟
deep convective weather
hail
cloud physical structure
microphysical mechanism
WRF
model simulation
