广东一次超级单体龙卷的多普勒天气雷达特征分析  

Analysis of Doppler Radar Features of a Supercell Tornado in Guangdong Province

作　　者：陈爱军[1,2] 冯喆[1,2] 胡胜[3] 

机构地区：[1]南京信息工程大学中国气象局气溶胶与云降水重点开放实验室,南京210044 [2]南京信息工程大学大气物理学院,南京210044 [3]广东省气象台,广州510080

出　　处：《科学技术与工程》2015年第23期1-8,27,共9页Science Technology and Engineering

基　　金：广东省科技计划项目(2013B020200012);公益性行业(气象)科研专项(GYHY201406009);江苏省政府留学基金;国家自然科学基金项目(40875015)共同资助

摘　　要：利用常规观测资料、NCEP 1°×1°再分析资料和广州多普勒天气雷达资料,对2011年5月7日发生在广东省佛山市的一次龙卷天气过程进行了分析。结果表明:此次龙卷产生于有利的天气形势下,环境场具有较大的大气不稳定度、充沛的水汽条件、强的垂直风切变以及低的抬升凝结高度。多个风暴单体的合并使对流强度得到增强并诱发了龙卷。反射率因子回波形态具有经典超级单体结构,钩状回波明显,反射率因子剖面存在有界弱回波区。钩状回波处产生了中气旋且维持了三个体扫,中气旋强度较强并逐渐向低层发展。龙卷发生前10 min出现了龙卷涡旋特征,表现为0.5°(距地面约500 m)径向速度图上沿方位角方向两个紧挨着的像素之间的强烈速度切变,说明此时漏斗云已从超级单体母云内向下伸展。综合分析各种雷达产品,可获得10 min左右的预警时间。A tornado process occurring in Foshan, Guangdong, May 7th, 2011, was analyzed using the conven- tional observation data, NCEP 1 ° × 1 ° reanalysis data and the data from the Doppler weather radar set up in Guang- zhou. The results indicated that this tornado formed in favorable weather conditions, including high atmospheric in- stability, abundant moisture, strong vertical wind shear, and low lifting concentration level in the ambient environ- ment. The convergence of multiple storm cells intensified in reflectivity data revealed classical supereell structure, the convection and induced the tornado. The echo pattern obvious hook echo, and the presence of Bounded Weak Echo Region in the reflectivity profile. The mesocyclone formed in hook echo and lasted for a duration of three times of volume scanning. The mesocyclone was strong and gradually developed to low-level mesocyelone. Tornado Vortex Signature occurred 10 minutes in advance of the tornado. Two adjacent pixels in the direction of azimuth an- gle in the radial velocity map exhibited strong wind shear at an angle of 0.5 degree （500 m above the ground）, in- dicating that funnel cloud had extended below the parent supereell storms. Ten minutes of pre-warning time can be achieved through a comprehensive analysis of the data from radar products.

关 键 词：龙卷 经典超级单体 中气旋 龙卷涡旋特征 多普勒天气雷达 

分 类 号：P445.1[天文地球—大气科学及气象学]