一次雹暴过程中对流系统演变特征的模拟分析  

Simulation Analysis of Evolution Characteristics of the Convective System during a Hail Storm Course

作　　者：吴海英[1,2] 曾明剑[1,3] 蒋义芳 梅海霞[1,3] 张冰[1,3] WU Haiying;ZENG Mingjian;JIANG Yifang;MEI Haixia;ZHANG Bing(Key Laboratory of Transportation Meteorology,China Meteorological Administration,Nanjing 210009,Jiangsu,China;Jiangsu Meteorological Bureau,Nanjing 210008,Jiangsu,China;Jiangsu Institute of Meteorological Sciences,Nanjing 210009,Jiangsu,China)

机构地区：[1]中国气象局交通气象重点开发实验室,江苏南京210009 [2]江苏省气象台,江苏南京210008 [3]江苏省气象科学研究所,江苏南京210009

出　　处：《高原气象》2021年第3期569-579,共11页Plateau Meteorology

基　　金：国家重点研发计划重点专项(2017YFC1502104);江苏省“333工程”科研资助项目(BRA2018100);江苏省自然基金项目(BK20201506)。

摘　　要：利用区域高分辨率数值模式WRF对2015年4月28日冷涡背景下发生在苏皖地区的冰雹过程进行模拟,并结合地面加密自动站、多普勒天气雷达等观测资料讨论了此次过程中对流系统结构演变特征及影响其组织发展的可能机制。结果表明:导致冰雹的对流系统在发展、传播及组织过程中与中尺度重力波相联系,重力波源于地面中尺度低压附近的初始对流的强烈发展,在条件性不稳定和较强的垂直风切变环境中传播,激发并组织形成一列波状结构的对流风暴,这列风暴动力结构高度组织化,上升-下沉气流相间排列,每个风暴内伴有强盛的上升气流,位于风暴后侧的下沉气流至地面后在风暴低层前后两侧各形成一支次级环流,将这列风暴单体有序地组织成波状对流带,对流风暴与重力波通过wave-CISK机制相互促进与发展,导致苏皖北部出现冰雹带。随着大气层结不稳定进一步发展,重力波的传播环境不再适宜,对流风暴列发展不平衡,波列前端的风暴单体加强,后部的风暴减弱,波列状结构特征逐渐改变。The high resolution numerical model WRF is used to simulate the hail weather occurring over Jiangsu and Anhui provinces on 28 April 2015 under the background of cold vortex. Combined with simulation data and observation data such as surface dense automatic station and Doppler weather radar,the evolution characteristics of the convective system structure and the possible mechanism affecting its organization and development are studied. The results show that the development,propagating and organization of the convective system causing hails is associated with the mesoscale gravity wave,which is triggered during the development of initial convection near the mesoscale low pressure. Then gravity waves motivate and organize a row of wavelike convective stormss during propagating in the conditional instability and strong vertical wind shear environment. The dynamic structure of the convective storms train is highly organized with updraft and downdraft flows arranged alternately. Each storm is accompanied by strong updraft,and the downdraft behind the storm reaches the ground and form a secondary circulation on both sides of the front and back of the low level of the storm,then the belt of wavelike convective storms are well-organized. Convective storms and gravity wave promote and develop mutually by means of wave-CISK mechanism,thus lead to the sequence of hail occurring in the north of Jiangsu and Anhui provinces. With the further development of stratification instability,the propagation environment of gravity wave is no longer suitable,and the development of convective storm train is unbalanced. The storm cell at the front of the wave train is strengthened,while the storm at the back is weakened,and the wavelike structure is gradually changed.

关 键 词：冰雹 对流风暴 风暴结构 模拟 中尺度重力波 

分 类 号：P458.1[天文地球—大气科学及气象学]