Collaborative Research: Damage Analysis and Numerical Simulation of Convectively Driven Wind Events Observed during the Bow Echo and Mesoscale Vortex Experiment (BAMEX)

合作研究：弓回波和中尺度涡实验（BAMEX）期间观测到的对流驱动风事件的损伤分析和数值模拟

• 批准号: 0233178
• 负责人: Nolan Atkins
• 金额: --
• 依托单位: Lyndon State College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0233178&HistoricalAwards=false
• 关键词: Collaborative; Research; Damage; Analysis; Numerical

The bow echo is known as a prolific producer of severe, though primarily non-tornadic, wind damage at the ground. The generally accepted explanation for the damaging wind involves a strong surface cold pool and associated rear-inflow jet (RIJ) that descends to the ground behind the apex of the bow. Recent idealized numerical simulations and limited observations are suggesting a different model, in which damaging surface winds are also induced tens of kilometers north of the apex by low-level, meso-gamma scale (order 10 km diameter) vertical vortices. Simulations suggest that, under certain conditions, mesovortex winds can be stronger, have longer durations, and produce a larger area of significant damage than can the RIJ winds at the apex. Adequate observations to validate this new explanation have yet to be collected. Further, the generality of this damaging-wind producing mechanism has yet to be established in instances when the mesoscale environment of the bow echo is significantly inhomogeneous. Underscoring the importance of this are recent observational studies that indicate a relation between reports of damaging straight-line (and/or tornadic) winds and the interaction of a bow echo and mutually perpendicular "external" outflow boundary.The primary objectives of this research are to: (i) conduct detailed aerial and ground surveys of wind damage following bow echo events, relating the severity and scale of damage to radar-observed convective system location and structural characteristics; and (ii) perform analyses and mesoscale model simulations of bow echo events in order to investigate dependencies of damaging winds, meso-vortexgenesis, and convective system structure on the inhomogeneous mesoscale environment. The bow echo and mesoscale convective vortices (MCV) experiment (BAMEX) will provide the framework for the proposed work. BAMEX seeks to understand and improve prediction of: the meso- and cellular-scale processes, within bow-shaped mesoscale convective systems, that lead to damaging winds at the ground; and MCVs and the deep cumulus convection they often trigger. BAMEX will be conducted over a large experimental domain centered on St. Louis, Missouri, and will involve unprecedented data collection via specialized airborne and ground-based observing platforms. Post-event damage surveys, a critical component of the BAMEX dataset, will be conducted under this award and used to meet numerous BAMEX objectives beyond those to be addressed under this award.The results of this research will significantly clarify the understanding of damaging wind production in bow echoes and will illuminate where the most damaging winds are most likely to occur, with what radar-observable attributes, and under what mesoscale environmental conditions. Ultimately, results may be applied by operational forecasters to issue more timely and accurate forecasts and warnings of damaging nontornadic surface winds.

弓回声被称为严重的多产生产商，尽管主要是非腹部的风损伤。 有害风的普遍接受的解释涉及一个强烈的表面冷池和相关的后流射流（RIJ），该射流降落到弓顶点后面的地面。 最近的理想化数值模拟和有限的观察结果表明了一个不同的模型，其中，有破坏性的表面风也通过低水平的中毛，中间尺度（直径10 km）垂直涡旋引起了顶点以北数十公里。 模拟表明，在某些条件下，中腹风可以更强，持续时间更长，并且与顶点处的RIJ风相比，造成更大的损坏区域。 尚未收集足够的观察来验证这种新的解释。 此外，这种有害风的产生机制的普遍性尚未在弓形的中尺度环境显着不均匀的情况下建立。 强调这一点的重要性是最近的观察性研究，表明损害直线（和/或龙卷风）风的报告与弓形的相互作用与相互回声和相互垂直的“外部”流出边界的相互作用之间的关系。这项研究的主要目标是：（i）在以下方面进行：（i）在以下方面进行详细的和地面损害，并在弓箭上造成了范围，并施加了范围内的范围，范围内的范围范围范围范围范围范围，划定的范围范围和范围内的范围范围范围范围，并且规模范围是弓箭范围，并且规模范围是弓箭的范围，并且范围内的范围范围范围范围范围范围，并且规模范围范围范围范围内的范围内的范围，领域的规模范围和范围。和结构特征； （ii）对BOW回声事件进行分析和中尺度模型模拟，以研究对不均匀性中尺度环境的损害风，中涡质量和对流系统结构的依赖性。 Bow回声和中尺度对流涡旋（MCV）实验（Bamex）将为拟议的工作提供框架。 Bamex试图理解和改善：弓形中尺度对流系统内的中层和细胞尺度过程，导致地面造成损坏的风；他们经常触发MCV和深层对流。 Bamex将在以密苏里州圣路易斯为中心的大型实验领域进行，并将通过专门的机载和地面观测平台进行前所未有的数据收集。 事件后损伤调查是该奖项的重要组成部分，是该奖项的重要组成部分，并用于达到该奖项之外的许多Bamex目标。这项研究的结果将大大阐明弓箭的损害生产的理解，并将在最可能发生的环境中遇到最可能发生的情况，并在范围内遇到最大的损害。 最终，运营预测者可以应用结果，以发出更及时，准确的预测和警告，并警告破坏非洋田的表面风。