摘要
利用地面、高空和FY-2C卫星云图资料,分析了2005年6月14~15日发生在山东、江苏和安徽的一次极端冰雹过程。结果表明:(1)东北冷涡底部的前倾槽结构有利于不稳定层结的形成与维持,低层西南气流为冰雹的发生提供了水汽,地面中尺度辐合线和露点锋是其主要触发机制。(2)0~6 km强垂直风切变、平均对流有效位能超过2000 J·kg^(−1)和湿球0℃平均高度3.8 km,这些有利条件为极端冰雹天气提供了合适的环境场。(3)红外云图上,亮温(TBB)显示冷云盖的重心呈现“西重东轻”的偏心现象,降雹区在云团右侧TBB梯度大值区及其附近,不同地区极端冰雹产生于中尺度对流系统(MCS)发展的不同阶段,其强度和尺寸差异显著。(4)水汽云图上,冷涡后部干空气前沿与湿空气相互作用触发新的对流,形成后向传播;暗区强度增强,MCS发展;暗区入侵到云团内部,MCS分裂;暗区强度减弱,MCS对流减弱。
Based on ground,high-altitude observations and the FY-2C Satellite Cloud Image data,a severe hail process occurred in Shandong,Jiangsu and Anhui provinces from June 14 to 15,2005 was analyzed.The results show that:(1)The forward trough structure at the deep of the northeast cold vortex was favorable for the formation and maintenance of the unstable stratification,and the southwesterly airflow at the lower level provided water vapor for the occurrence of hail,and the meso-scale convergence line and dew point front on the ground were the main trigger mechanisms.(2)0~6 km strong vertical wind shear,convective effective potential energy greater than 2000 J·Kg^(−1),average height of wet bulb at 0°C was 3.8 km,these favorable conditions provided a suitable environment field for this severe hail.(3)The TBB showed that the center of gravity of the cold cloud cover was lightly eccentric from the west to the east,and the hail area mainly occurred in and near the large cloud top TBB gradient area on the right side of the cloud.(4)The front of the dry air behind the cold vortex interactd with the wet air,triggering new convection and forming the backward propagation.The intensity of the dark area of the cloud map increased and MCS developd.When the intensity of the dark area invaded into the cloud cluster,the MCS split accordingly.When the dark area weakened,the MCS convection weakened.
作者
汤兴芝
黄治勇
王金兰
姚瑶
TANG Xingzhi;HUANG Zhiyong;WANG Jinlan;YAO Yao(Hubei Branch of CMA Training Centre,Wuhan 430074,China;Xinxiang Meteorological Bureau of Henan,Xinxiang 453003,China)
出处
《高原山地气象研究》
2023年第2期59-66,共8页
Plateau and Mountain Meteorology Research
基金
国家自然科学基金面上项目 (41975058)
中国气象局气象干部学院课题(青 2021-013)。
关键词
极端冰雹
中尺度对流系统(MCS)
后向传播
红外云图
水汽云图
Huge hail
Mesoscale convective system(MCS)
Backward propagation
Infrared cloud image
Water vapor cloud image
