AGS-PRF: Daytime to Nocturnal Convective Transition in the Central United States

该奖项将为博士后研究人员提供资金，以研究雷暴的性质如何在从白天到夜晚的过渡期间发生变化。 在白天，雷暴是由地面的太阳能加热而产生的，被称为地面雷暴。 当太阳落山，地面开始冷却时，进入雷暴的气流变得升高，雷暴往往合并成一个更大的复杂系统，称为中尺度对流系统（MCS）。 计算机模型不能很好地捕捉这种转变，预测MCS是否会形成以及它可能存活多久变得非常困难。 这项研究将利用数值模拟和观测来研究过渡。 这项研究应该为预报员提供更多关于这些危险的夜间事件的信息，这些事件可能包含强风和洪水。 研究人员还希望与其他同事联系，以确定公众如何解释这些类型的事件的预测，以提高整体公共安全。研究人员计划通过一系列数值模拟实验和高分辨率实地观测分析，提高对对流夜间转换动力学的基本理解。 两个主要的研究问题将被解决：1）如何增加行星边界层的稳定性，增加低空急流强度，并增加低层升力沿着终端的低空急流影响高档增长和行为的对流在夜间过渡和2）夜间过渡MCS的现场观测证实的结果从数值实验？ 研究人员将进行理想化的数值实验来解决第一个问题，然后对夜间平原高架对流（PECAN）现场活动的数据进行分析。

This award will provide funding for a postdoctoral researcher to study how the character of thunderstorms changes during the transition from day to night. During the day, thunderstorms feed off of the solar heating of the ground and are referred to as surface-based. When the sun sets and the ground begins to cool, the air flow into the thunderstorms becomes elevated and the thunderstorms often consolidate into a larger complex known as a mesoscale convective system (MCS). Computer models do not capture this transition well and forecasting of whether an MCS will form and how long it may survive becomes very difficult. This study will make use of both numerical modeling and observations to study the transition. The research should provide forecasters with more information about these hazardous nocturnal events which can contain severe winds and flooding rains. The researcher also would like to connect with other colleagues to determine how the public interprets forecasts for these types of events with an eye towards improving overall public safety.The researcher plans to improve basic understanding of the dynamics of the nocturnal transition of convection through a series of numerical modeling experiments and analysis of high-resolution field observations. Two main research questions will be addressed: 1) How do increasing planetary boundary layer stability, increasing low-level jet strength, and increasing low-level lift along the terminus of the low-level jet influence upscale growth and behavior of convection during nocturnal transition and 2) Do field observations of nocturnal transitioning MCSs corroborate the results from numerical experiments? The researcher will perform idealized numerical experiments to address the first question and then follow-up with analysis of data from the Plains Elevated Convection at Night (PECAN) field campaign.