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

AGS-PRF：美国中部白天到夜间的对流转变

• 批准号: 1524435
• 负责人: John Peters
• 金额: $ 8.6万
• 依托单位: Peters John M
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1524435&HistoricalAwards=false
• 关键词: AGS; PRF; Daytime; Nocturnal; Convective

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.

该奖项将为博士后研究员提供资金，以研究雷暴的特征在白天到夜晚的过渡过程中如何变化。 白天，雷暴来自地面的太阳加热，被称为地面雷暴。 当太阳落山并且地面开始变冷时，进入雷暴的气流就会升高，雷暴通常会合并成一个更大的复合体，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，因此预测 MCS 是否会形成以及它可以存活多久变得非常困难。 这项研究将利用数值模型和观测来研究这一转变。 这项研究应该为预报员提供有关这些危险夜间事件的更多信息，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，以确定公众如何解读此类事件的预测，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现场观测分析，增进对对流夜间转变动力学的基本了解。 将解决两个主要研究问题：1）增加行星边界层稳定性、增加低空急流强度以及增加沿低空急流终点的低空升力如何影响夜间过渡期间对流的高尺度增长和行为；2）夜间过渡MCS的现场观测是否证实了数值实验的结果？ 研究人员将进行理想化的数值实验来解决第一个问题，然后对平原夜间高对流 (PECAN) 现场活动的数据进行后续分析。