摘要
利用海口多普勒雷达、海南省区域加密自动站和常规资料对2016年4月11日凌晨发生在海南岛北部近海和陆地的大范围雷暴大风过程进行天气学分析。结果表明:(1)这次雷暴大风过程发生在500 h Pa槽前、低空急流左前侧、低层切变线南侧、高空急流分流区下方和地面静止锋南侧的有利于对流发展的较大范围上升气流区域内;(2)对流风暴移动路径上的大气环境具有中等程度的条件不稳定、对流有效位能CAPE以及上干冷下暖湿的温-湿廓线垂直结构、强的深层垂直风切变,对流风暴形成后最终组织发展产生雷暴大风、大冰雹和短时强降水的多单体带状回波和弓形回波;(3)在多单体带状回波中镶嵌的风暴A和B各自发展成为具有中层径向辐合特征的超级单体,风暴B和C合并形成弓形回波,其中风暴C的中气旋加强成为弓形回波北部的气旋式中尺度涡旋;(4)阵风锋对对流风暴的正反馈作用、对流风暴前侧强劲的暖湿入流与风暴后侧径向风速相当的冷池出流,长时间倾斜依存的自组织结构及其与强的低层环境风垂直切变的相互作用,是多单体风暴和弓形回波长时间维持和加强的主要原因;(5)地面原来存在的β中尺度辐合切变线,对流风暴主体回波沿着海南岛北部近海东移等因素,有利于多单体带状回波和弓形回波的长时间维持。
A destructive wind event, with occurred on 11 April 2016 extensively and caused great damage and casualties in the north of Hainan Island, is analyzed based on Doppler radar, intensive automatic weather stations, and conventional meteorological stations. The result shows that an extended region of intense vertical upward motion in the front of a 500hPa trough, the left front of a low-level jet, the south of a low-level shear line, the south side of a ground stationary front and the diverging area of an upper-level jet provided favorable conditions for strong convective development. The convective storm formed in the conditions of moderate instability and convective available potential energy （CAPE）, vertical profile of temperature and humidity with a dry and cold upper level, a wet and warm lower level, and a strong vertical wind shear. The typical features of hook echo and bow echo were found when the convective storm developed with strong wind, heavy hail and short time heavy rainfall. In this case, two storms （called storm A and B） developed into a supercell convective storm （storm C） with strong middle-altitude radial velocity. Storm B and C merged and formed a bow echo, and a mesocyclone with storm C became a mesoscale cyclonic eddy at the north part of the bow echo. A rear downdraft jet of the bow echo in the 0.2 to 2km height maintained the maximum radar radial velocity at 39m/s, and the entrainment of dry air resulted in the rapid evaporation of rain and the cooling of hail, which accelerated the descending air flow. A strong warm moist inflow in the front of the convective storm and a cold pool of the rear outflow obliquely coexisted with equivalent wind speed. Positive feedback of the gust front and its interaction with low-level vertical wind shear caused long-time maintenance and the enhancement of a self-organized mechanism made multiple-cell band storm and bow echo to strengthen and maintain. Multiple influential factors, such as the pre-existing meso-fl-scale convergence shear on the gr
作者
郑艳
俞小鼎
蔡亲波
任福民
ZHENG Yan;YU Xiao-ding;CAI Qin-bo;REN Fu-min(Hainan Meteorological Observatory, Haikou 570203, China;China Meteorological Administration Training Centre, Beijing 100081, China;Chinese Academy of Meteorological Science, State Key Laboratory of Severe Weather, Beijing 100081, China)
出处
《热带气象学报》
CSCD
北大核心
2017年第6期850-860,共11页
Journal of Tropical Meteorology
基金
海南省自然科学基金项目(414200)
华南大风行业专项(GYHY201406002)
国家自然科学基金项目(41175043)
公益性行业(气象)科研专项(GYHY201306009)共同资助
