一次典型超级单体风暴的多普勒天气雷达观测分析
ANALYSIS OF A STRONG CLASSIC SUPERCELL STORM WITH DOPPLER WEATHER RADAR DATA
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摘要: 文中利用位于安徽合肥的S波段多普勒天气雷达资料,对2002年5月27日14~20时发生在皖北地区的一次典型的超级单体风暴过程进行了详细的分析。此次超级单体南边出现两条明显的出流边界,一条位于钩状回波的西南,一条位于钩状回波的东南。超级单体左前方的低层反射率因子呈现明显的倒“V”字型结构,这也是超级单体风暴的典型特征之一。沿入流方向穿过最强回波位置的反射率因子垂直剖面呈现出典型的有界弱回波区(穹隆)、强大的回波悬垂和有界弱回波区左侧的回波墙。最大的回波强度出现在沿着回波墙的一个竖直的狭长区域,其值超过70dBz。相应的中低层径向速度图呈现一个强烈的中气旋,旋转速度达到22m/s。风暴顶为强烈辐散,正负速度差值达63m/s。相应的垂直累积液态水含量和密度分别超过70kg/m2和5g/m3。因此,该风暴具有强烈超级单体风暴的典型特征。该超级单体的移动方向在盛行风向的右侧约30°,属于右移风暴。Abstract: In the paper, a detailed analysis is made, by using the Hefei Doppler Weather Radar data on a strong classic supercell storm which occurred on 27 May 2002 in the north of Anhui province. This supercell storm originated from a multicell storm which first appeared at 13:20 on 27 May 2002 between the Haozhou and Woyang county in the northwest of Anhui. The storm moved in southeast east direction during the following several hours. Around 16:00, the storm evolved into the supercell storm, and remained as a supercell for the following 1 hour. After 17:00, it lost its supercell identity and evolved into a squall line. The squall line moved into north Jiangsu province around 21:00.