吴芳芳,俞小鼎,张志刚,周小刚,韦莹莹. 2013. 苏北地区超级单体风暴环境条件与雷达回波特征[J]. 气象学报, 71(2):209-227, doi:10.11676/qxxb2013.016
苏北地区超级单体风暴环境条件与雷达回波特征
A study of the environmental conditions and radar echo characteristics of the supercell-storms in northern Jiangsu
投稿时间:2012-04-24  修订日期:2012-07-09
DOI:10.11676/qxxb2013.016
中文关键词:  超级单体  苏北地区  环境条件  雷达回波特征  强对流天气
英文关键词:Superccll-storms  Northern Jiangsu  Environmental conditions  Radar echo characteristics  Severe connective weather
基金项目:国家自然科学基金(41175043、40575014);中国气象局强对流天气研究创新专家团队项目、中国气象局预报员专项(CMAYB2013-025)和南京雷达气象与强天气开放实验室研究基金(BJG201212)
作者单位
吴芳芳 江苏省盐城市气象局, 盐城, 224005 
俞小鼎 中国气象局气象干部培训学院, 北京, 100081 
张志刚 江苏省盐城市气象局, 盐城, 224005 
周小刚 中国气象局气象干部培训学院, 北京, 100081 
韦莹莹 江苏省盐城市气象局, 盐城, 224005 
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中文摘要:
      利用江苏3个探空站、5部CINRAD/SA 型多普勒天气雷达、地面常规与加密自动站等观测资料, 分析2005-2009 年苏北地区72个超级单体风暴发生的环境条件和多普勒天气雷达回波特征。探空和地面资料分析表明, 苏北地区超级单体风暴可以产生在差别相当大的环境条件下:强降水超级单体通常产生在对流有效位能较高和垂直风切变中等的环境下, 经典 超级单体更多地产生在对流有效位能较高和垂直风切变较强环境下;产生大冰雹和(或)雷暴大风的超级单体, 无论是经典还 是强降水型超级单体, 其环境特征均为0℃层、-20℃等温线高度较低, 850-500hPa温差较大, 低层露点不高;产生龙卷特别 是F2级以上强龙卷超级单体环境特征常常表现为低层(0-1km)垂直风切变大、850-500hPa温差相对较小、抬升凝结高度 低、低层露点高, 这类超级单体在产生龙卷的同时也常常伴有短时强降水甚至极端短时强降水。多普勒天气雷达资料分析表 明, 苏北地区超级单体具有持久的中气旋、回波墙和有界弱回波区或弱回波区结构, 可以产生大冰雹、龙卷、短时强降水和下 击暴流等强对流天气;超级单体的类型主要有经典超级单体、强降水超级单体以及强降水超级单体组成的复合风暴。经典超 级单体一般为孤立风暴, 中气旋多数情况下位于其右后侧(相对于风暴移动方向),低层有明显的钩状回波和入流缺口, 入流 缺口之上存在宽大的有界弱回波区, 其上有强反射率因子组成的风暴核, 最强的反射率因子可达75dBz;强降水超级单体前 侧有入流缺口和旁边粗胖的凸起部分与中气旋相伴, 与经典超级单体的钩状回波在形态上区别明显, 同样存在有界弱回波区 或弱回波区, 中气旋环流中有明显的降水回波;强降水超级单体组成的复合风暴内中气旋一般位于其前侧, 主要结构与强降 水超级单体相似, 生命史较长。超级单体结构属性分析表明, 绝大多数情况下, 苏北地区超级单体风暴的最大反射率因子为 55-76dBz,基于单体的垂直累积液态水含量(VIL)为35-90kg/m2,垂直累积液态水含量超过60kg/m2 时风暴有可能产生 大冰雹, 特别是在4-6月, 冰雹直径随着垂直累积液态水含量的增大而增大, 因此, 垂直累积液态水含量季节性高值可以用来 辨别产生大冰雹的超级单体;绝大多数情况下, 中气旋旋转速度大于15m/s,直径在3-10km,持续时间超过40min;中气旋 的底越低, 直径越小, 产生龙卷的可能性越大。
英文摘要:
      The environmental conditions and radar echo features of the 72 superccll-storms in northern Jiangsu Province arc in-vcstigated, based on the data from 5 Doppler weather radars,3 radiosonde stations, and surface weather stations during the 2005-2009. The sounding analyses indicate that high precipitation supercells usually occur with very high CAPE, medium deep layer(0-6 km) vertical wind shear, and high value of low level dewpoint, while classic suppercells occur with high CAPE, strong deep layer vertical wind shear, and moderate low level dewpoint. Supercells producing large hailstones and/or strong wind gust occur in the environment with lower height of 0℃ and 20℃ levels, relatively sharp lapse rate of temperature, strong deep layer vertical wind shear, and moderate surface dewpoints. However, the tornadic supercells occur in the environment with strong lower level (0-1 km) vertical wind shear, lower LCL, less lapse rate of temperature, and high surface dew-points, frequently accompanied by flash heavy rain. The results of Doppler weather radar echoes analysis shows that there are three types of supercell storms in northern Jiangsu:classical supcrcells, high precipitation supercells, and high precipitation supercell complexes. A classical supercell is usually isolated, with a mesocyclone at rear-right flank(relative to storm moving dircetion), a hook echo at low level, and a high reflectivity core above a broad bounded weak echo region(BWER).A high pre-cipitation supcrcell has a front inflow notch with a mesocyclone, a wide bow-shaped echo next to the inflow notch at low level, and a BWER or WER, with the mesocyclone circulations filled with precipitation. high precipitation superccll complexes have a similar structure to the high precipitation, but with longer life time. The storm cell characteristics analysis displays that, in majority of cases, the strongest echoes of the supercells range from 55 dBz to 76 dBz, the vertical integrated liquid(VIL) from 35 kg/m2 to 90 kg/m2, the rotation speed of m esocyclones is greater 15 m/s, and the duration over 40 minutes. High probability of tornados can be expected when a mesocyclone possesses very low base and smaller diameter.
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