Collaborative Research: Processes that Regulate Vertical Accelerations in Supercell Updrafts

超级单体雷暴中特别强烈的上升气流促进了大冰雹、龙卷风、极端降雨率和多产闪电的产生。由于它们对社会的巨大影响，有必要进行大量的研究工作，以更好地了解和预测有助于垂直加速度的环境因素，这些因素让位于超级单体令人印象深刻的上升气流。这项合作研究工作将利用大量创新的高分辨率数值模拟实验以及观测数据集，以了解在一系列现实的近风暴环境中，不同高度的超级单体上升气流的强迫。因此，这项工作对社会产生了更广泛的影响，因为它有可能改善对超级单体雷暴及其相关危害的理解和预测，并通过培训新一代科学家。由于目前对这些领域缺乏全面的了解，本研究将探讨以下科学问题：（1）低层稳定度、低层切变和低层风暴相对流如何共同确定风暴的有效入流层？(2)在傍晚转捩期间，低层稳定度和切变的同时变化如何影响从不同层吸入的空气的比例以及超级单体上升气流下部浮力和动压加速度的垂直廓线？(3)风暴相对流和上升气流宽度之间的联系如何影响上升气流的浮力和动态垂直加速度的剖面？ 这些问题将通过数值模拟来回答，数值模拟的范围从高度理想化到观测到的风暴的真实数据模拟，其中有效流入层，上升气流强迫，和夹带将进行比较和验证，通过双-多普勒雷达观测。该奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值的支持和更广泛的影响审查标准。

The especially intense updrafts in supercell thunderstorms facilitate the production of large hail, tornadoes, extreme rainfall rates, and prolific lightning. As a result of their great impacts on society, considerable research efforts are warranted to better understand and predict the environmental factors that contribute to the vertical accelerations that give way to supercells' impressive updrafts. This collaborative research effort will utilize numerous, innovative high-resolution numerical modeling experiments coupled with observational datasets in order to understand the forcing for supercell updrafts at various heights over a range of realistic near-storm environments. Thus, this work has tangible broader impacts to society through its potential to improve understanding and forecasting of supercell thunderstorms and their related hazards as well as through training of a new generation of scientists. Motivated by a current lack of comprehensive understanding in these areas, this research will investigate the following scientific questions: (1) How do low-level stability, low-level shear, and low-level storm-relative flow conspire to determine a storm's effective inflow layer? (2) How do concurrent changes in low-level stability and shear, as occurs during the evening transition, influence the ratio of air ingested from different layers and the vertical profiles of buoyant and dynamic pressure accelerations in the lower portion of a supercell updraft? (3) How might the connection between storm-relative flow and updraft width influence an updraft's profile of buoyant and dynamic vertical accelerations? These questions will be answered using numerical simulations with a range of realism from highly idealized to real-data simulations of observed storms, wherein quantities such as the effective inflow layer, updraft forcing, and entrainment will be compared and verified via dual-Doppler radar observations when available.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.