Volatility of Tornadogenesis: An Ensemble of Simulated Nontornadic and Tornadic Supercells in VORTEX2 Environments
Volatility of Tornadogenesis: An Ensemble of Simulated Nontornadic and Tornadic Supercells in VORTEX2 Environments
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龙卷发生的波动性：VORTEX2 环境中模拟非龙卷风和龙卷风超级单体的集合
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
A. Clark
中科院分区：
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作者：
Brice E Coffer;M. Parker;Johannes M. L. Dahl;Louis J. Wicker;A. Clark
摘要尽管人们对有利于龙卷风形成的环境有了越来越多的了解，但龙卷风警报的高误报率仍然存在，这表明龙卷风的形成可能是一个不稳定的过程，主要是每次风暴的内部。为了评估这一点，基于第二次龙卷风旋转起源验证实验（VORTEX2）合成的非龙卷风和龙卷风环境剖面的微小变化，构建了30个超级单体模拟集合。尽管发生在相似的环境中，所有的模拟都会产生不同的超级细胞。龙卷风和非龙卷风集合成员都具有充足的亚龙卷风表面垂直涡度；决定性因素是这种涡度能否被低层上升气流汇聚和拉伸。龙卷风涡旋2的15个成员中的每一个都会产生长轨迹、强烈的龙卷风。虽然降水和近地表浮力场存在显著差异，但每次风暴都具有不同的特征。
AbstractDespite an increased understanding of the environments that favor tornado formation, a high false-alarm rate for tornado warnings still exists, suggesting that tornado formation could be a volatile process that is largely internal to each storm. To assess this, an ensemble of 30 supercell simulations was constructed based on small variations to the nontornadic and tornadic environmental profiles composited from the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2). All simulations produce distinct supercells despite occurring in similar environments. Both the tornadic and nontornadic ensemble members possess ample subtornadic surface vertical vorticity; the determinative factor is whether this vorticity can be converged and stretched by the low-level updraft. Each of the 15 members in the tornadic VORTEX2 ensemble produces a long-track, intense tornado. Although there are notable differences in the precipitation and near-surface buoyancy fields, each storm features s...