侯淑梅,俞小鼎,张少林,刘畅,王俊,万明波. 2015. 山东中西部后向发展雷暴初步研究[J]. 气象学报, 73(5):819-836, doi:10.11676/qxxb2015.059
山东中西部后向发展雷暴初步研究
A preliminary investigation into the back-development thunderstorms in midwestern Shandong Provience
投稿时间:2014-08-22  修订日期:2015-04-23
DOI:10.11676/qxxb2015.059
中文关键词:  后向发展雷暴  山东中西部  时空分布  雷达回波演变分类  新雷暴生成模态  物理机制
英文关键词:Back-development thunderstorms  Midwestern part Shandong Province  Spatial-temporal distribution  Classification of radar echo evolution  Modes of new thunderstorm genesis  Physical mechanisms
基金项目:国家自然科学基金项目(41275044)、国家973计划项目(2013CB430103)、山东省气象局课题(2012sdqx04、2014sdqxm21)。
作者单位E-mail
侯淑梅 山东省气象台, 济南, 250031  
俞小鼎 中国气象局气象干部培训学院, 北京, 100081 xdyu1962@126.com 
张少林 山东省气象台, 济南, 250031  
刘畅 山东省气象台, 济南, 250031  
王俊 山东省人民政府人工影响天气办公室, 济南, 250031  
万明波 山东省气象台, 济南, 250031  
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中文摘要:
      基于山东济南新一代天气雷达多年资料,首先提出后向发展雷暴的概念,并规定了普查标准。通过普查2005—2012年8年济南多普勒天气雷达资料,选取了75个后向发展雷暴个例,分析了山东中西部后向发展雷暴的统计特征,给出了常见的3种后向发展雷暴概念模型。选取典型个例,分别对3种类型后向发展雷暴的演变方式及其物理机制进行了初步分析,为山东中西部后向发展雷暴的生成和演变提供了初步的认识。结果表明:(1)后向发展雷暴主回波以带状为主,生命史1—5 h,最大反射率因子在50 dBz以上,移动路径有西—西北、西南、原地新生3种类型;(2)新回波初生时间发生在16—17时(北京时)最多,初生地点在鲁西北和鲁中山区一带,强度一般在30 min内超过40 dBz,生命史在1 h以上,74.7%的新生回波与主回波合并或连接;(3)山东省中西部具有后向发展特征的对流系统产生的灾害性天气以冰雹和雷暴大风为主,很少伴随暴雨灾害;(4)新回波的源地特征可以分为随主回波移动、沿同一方向延伸以及位于两雷暴群之间3种类型;多个雷暴群共存时,新回波的源地介于两个回波带之间,使二者逐渐趋为一体;(5)当主回波传播方向与其长轴相交时,其长轴方向转向,距离新回波较远的一侧减弱;当主回波传播方向与其长轴方向一致,新回波源地位于主回波长轴的延长线上时,主回波加强;(6)天气尺度系统为后向发展雷暴提供了条件不稳定的大气层结和丰富的水汽,地面辐合线和冷池前沿阵风锋是产生新雷暴的主要抬升触发机制;适当的低层垂直风切变有利于新雷暴持续产生并加强;地形的阻挡使新回波源地在同一地点停滞,冷池阵风锋在低层风引导下沿地形向下游移动,新回波源地也随之移动。
英文摘要:
      Based on eight year long data from the Jinan Doppler Weather Radar, first of all, the concept for the back-development thunderstorms and rules for their identification are given. Secondly, the 75 back-development thunderstorm cases have been selected by examining the Jinan Doppler Weather Radar data from 2005 to 2012, statistical analysis of the back-development thunderstorms has been conducted over the midwestern area of Shandong Province, and then three major conceptual models of the back-development thunderstorm are proposed. Finally, detailed analysis of the evolution modes and physical mechanism for the back-development thunderstorm are conducted by investigating several typical cases. Some clues on the conditions for the initiation, maintenance and development of the back-development thunderstorms in the midwestern area of Shandong Province are revealed and discussed. The results show that: (1) During the back-development events, the shapes of main echoes are always band-like, their lifespans are between 1 to 5 hour, the maximum reflectivity is over 50 dBz, and there are three types of main echo moving paths including northwest, southwest and local generation. (2) The initiation time of the new echoes are mostly at 16:00-17:00 BT, and their initial positions concentrate on the northwestern and central areas of Shandong Province, their intensity goes up to 40 dBz within 30 minutes, lifespan is greater than 1 hour, and 74.7% of the new echoes connect with the main echoes. (3) The major disastrous weather produced by the back-development thunderstorm are hail and wind gust, seldom accompanied by severe rain. (4) There are three types of original source regions for the new echoes: moving with the main echo, extending along one direction, and located between two groups of thunderstorms. In the cases of several groups of thunderstorms present, the original source regions of new echoes would lie between two thunderstorm clusters, so that the two groups of thunderstorms tend to merge with each other. (5) When the propagation direction of main echoes intersects its long axis, the direction of that axis will turn, and the intensity in the part of main echoes located further from the new echo will turn weaker; when the propagation direction of main echoes is parallel with its long axis, the new echoes would develop along the extending part of the main echo long axis, leading then the main echoes to strengthening. And, (6) the synoptic-scale weather system provides conditional unstable atmosphere and abundant water vapor, while the boundary layer convergence lines and gust front are the main lifting mechanisms for initiating the new echoes. The suitable low level (0-3 km) vertical wind shear is conductive to the continuous generation and strengthening for the new thunderstorms. The original source regions of the new echoes would stagnate in the same place due to the block of terrain. The gust front in the leading edge of the cold pool moves downstream along the terrain by the steering of lower-level wind, and then the original source regions of new echoes would move with the gust front.
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