Near-Ground Rotation in Simulated Supercells: On the Robustness of the Baroclinic Mechanism*
Near-Ground Rotation in Simulated Supercells: On the Robustness of the Baroclinic Mechanism*
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模拟超级单体中的近地旋转：斜压机制的鲁棒性*
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Johannes M. L. Dahl
中科院分区：
文献类型：
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作者：
Johannes M. L. Dahl
AbstractThis study addresses的鲁棒性的斜压机制，有利于发病的表面旋转的超级单体通过使用两个理想化的模拟与不同的微物理参数化，并考虑以前的结果。特别分析了环境涡度相对于斜压涡度在近地气旋性涡度发展中的重要性。风暴模拟使用CM1模式的运动学基本状态，其特征在于由直线速端。一个轨迹分析跨越约30分钟进行了大量的包裹，有助于近地面垂直涡度最大值。沿这些轨迹的涡度沿着被分解为正压和非正压部分，其中正压涡度代表预先存在的，基本上水平的风暴相对涡度的影响。非正压部分代表风暴内部斜压产生的涡度。它被发现...
AbstractThis study addresses the robustness of the baroclinic mechanism that facilitates the onset of surface rotation in supercells by using two idealized simulations with different microphysics parameterizations and by considering previous results. In particular, the importance of ambient crosswise vorticity relative to baroclinically generated vorticity in the development of near-ground cyclonic vorticity is analyzed. The storms were simulated using the CM1 model in a kinematic base state characterized by a straight-line hodograph. A trajectory analysis spanning about 30 min was performed for a large number of parcels that contribute to near-surface vertical-vorticity maxima. The vorticity along these trajectories was decomposed into barotropic and nonbarotropic parts, where the barotropic vorticity represents the effects of the preexisting, substantially crosswise horizontal storm-relative vorticity. The nonbarotropic part represents the vorticity produced baroclinically within the storm. It was found...