一次强对流系列风暴个例的多普勒天气雷达资料分析
CASE STUDY OF A SERIES OF SEVERE CONVECTIVE STORMS BASED ON CHINA NEW GENERATION (DOPPLER) WEATHER RADAR DATA
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摘要: 讨论了新一代(多普勒)天气雷达对2002年5月14日19:00至21:00影响湖南常德地区的3个对流风暴的探测情况,其中两个为超级单体,一个为飑线。观测到了与超级单体相联系的中气旋和龙卷式涡旋特征(TVS)。上述强对流系统产生了地面大风、大冰雹和龙卷等强烈天气,与雷达的探测相吻合。特别值得一提的是在中国首次探测到了三体散射(TBSS)和龙卷式涡旋特征(TVS)这两个分别指示大冰雹和龙卷的雷达回波特征,并得到了地面报告的印证。Abstract: Three severe convective storms occurring between 19:00 and 21:00 on 14 May 2002 in Changde area, Hunan Province are analyzed based on the new generation (Doppler) weather radar data. These severe storms led to heavy damage, producing wind gust as high as 26 m/s, 30 mm diameter large hails and tornado, in consistency with the radar observations. Among the three convective storms, two are supercell storms and one is squall line. The mesocyclones associated with the two supercells are identified. Both supercell storms produce the Three-Body Scatter Spike (TBSS), with the value of the reflectivity core over 70 dBz. A TWS (Tornadic Vortex Signature) associated with the second supercell storm is identified. Both the Three-Body Scatter Spike (TBSS) and Tornadic Vortex Signature (TVS), associated with large hails and tornado, respectively, have been observed for the first time in China, and large hails and tornado have been confirmed by the surface reports. Research results indicate that the TBSS can be used as a nowcasting index of large hails and high wind.
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图 7 造成三体散射长钉 (或火焰回波) 的雷达信号路径示意图
(点C处的阴影代表造成该回波假象的大于60 dBz的反射率因子核心 (引自文献[5]))
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