Insights into Supercells and Their Environments from Three Decades of Targeted Radiosonde Observations
Insights into Supercells and Their Environments from Three Decades of Targeted Radiosonde Observations
复制标题
从三个十年的定向无线电探空仪观测中深入了解超级细胞及其环境
DOI：
10.1175/mwr-d-20-0105.1
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发表时间：
2020
影响因子：
3.2
通讯作者：
Parker, Matthew D.
中科院分区：
文献类型：
--
作者：
Coniglio, Michael C.;Parker, Matthew D.
数以百计的超级单体接近探测获得的领域计划在美国中部进行了分析，以调和最近的研究中的差异，并完善我们的超级单体环境的知识。以风暴为中心的大型观测数据集和探测数据的高垂直分辨率为超级单体环境提供了前所未有的视角。毫不奇怪，风暴相对环境螺旋度（SRH）被发现是较大的龙卷风探测比在nontornadic探测。与以前的研究不同的主要发现是，风暴相对风对较大的SRH有很大的贡献。较强的地面相对风和更多的右偏风暴运动有助于较大的风暴相对风的龙卷风探测。空间分析的探测揭示了较低的近地面压力扰动和较强的低到中层气旋流的龙卷风探测，这表明更强的中气旋，也许解释了更多的右偏运动。龙卷风和非龙卷风测深之间的平均临界角差异很小，不会导致较大的平均SRH，但龙卷风测深确实有较少的较小（<60°）临界角的情况。此外，临界角被证明是从上升气流的方位角的函数。其他结果包括低到地面（平均约250米）速矢线扭结的龙卷风和非龙卷风的探测和一些显着的差异，热力学量，除了预期较低的LCL与较高的相对湿度的龙卷风探测，在龙卷风环境中的较小的0 -3公里的直减率与较弱/较浅的盖反转，和较大的0-3公里的CAPE在近场环境。
Hundreds of supercell proximity soundings obtained for field programs over the central United States are analyzed to reconcile differences in recent studies and to refine our knowledge of supercell environments. The large, storm-centric observation-based dataset and high vertical resolution of the sounding data provide an unprecedented look at supercell environments. Not surprisingly, storm-relative environmental helicity (SRH) is found to be larger in tornadic soundings than in nontornadic soundings. The primary finding that departs from previous studies is that storm-relative winds contribute substantially to the larger SRH. Stronger ground-relative winds and more rightward-deviant storm motions contribute to the larger storm-relative winds for the tornadic soundings. Spatial analyses of the soundings reveal lower near-ground pressure perturbations and stronger low- to midlevel cyclonic flow for the tornadic soundings, which suggests stronger mesocyclones, perhaps explaining the more rightward-deviant motions. Differences in the mean critical angle between the tornadic and nontornadic soundings are small and do not contribute to the larger mean SRH, but the tornadic soundings do have fewer instances of smaller (<60°) critical angles. Furthermore, the critical angle is shown to be a function of azimuth from the updraft. Other results include a low-to-the-ground (~250 m on average) hodograph kink for both the tornadic and nontornadic soundings and few notable differences in thermodynamic quantities, except for the expected lower LCLs related to higher RH for the tornadic soundings, somewhatsmaller0–3 km lapse rates in tornadic environments related to weaker/shallower capping inversions, and larger 0–3 km CAPE in near-field environments.