A possible mechanism of tornadogenesis associated with the interaction between a supercell and an outflow boundary without horizontal shear
A possible mechanism of tornadogenesis associated with the interaction between a supercell and an outflow boundary without horizontal shear
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与超级单体和无水平剪切的流出边界之间的相互作用相关的龙卷发生的可能机制
DOI：
10.1175/jas-d-14-0347.1
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发表时间：
2016
影响因子：
3.1
通讯作者：
Takumi Honda and Tetsuya Kawano
中科院分区：
文献类型：
--
作者：
Itoh;Y.;Kusumoto;S.;Takemura;K.;Yasuto Itoh;Yasuto Itoh;Takumi Honda and Tetsuya Kawano
利用本研究开发的插入-重新启动方法，研究了与超级单体和流出边界相互作用相关的龙卷风形成过程。在具有强表面涡的预条件超级单体中，高度理想化的流出边界促进了表面涡的增强。特别地，在一个中等流出边界的实验中，观察到一个类似龙卷风的涡旋。这种增强与外流边界对近地表水平辐合的增强有关。流出边界的最佳冷度是近地面水平辐合增强与流出边界浮力减弱之间的平衡。灵敏度实验表明，尽管环境不太有利，但具有边界相互作用的风暴可能达到与较有利环境下没有边界的风暴相似的最大近地面涡度。
Using the insert–restart method developed in this study, tornadogenesis processes associated with the interaction between a supercell and an outflow boundary were investigated. A highly idealized outflow boundary promoted surface vortex intensification in a preconditioned supercell having a strong surface vortex. In particular, a tornado-like vortex was observed in an experiment with a moderate outflow boundary. This intensification was associated with the enhancement of the near-surface horizontal convergence by the outflow boundary. The optimal coldness of the outflow boundary was explained by the balance between the enhancement of the near-surface horizontal convergence and the buoyancy reduction by the outflow boundary. Sensitivity experiments demonstrated that, despite a less favorable environment, a storm with a boundary interaction might reach a similar maximum near-surface vorticity as a storm without a boundary in a more favorable environment.