Collaborative Research: Physics Based Modeling of Blue Jets

在Sprites94飞机战役中，人们发现了从雷云顶部向上传播的狭窄的蓝光锥体。观测到了两种类型的蓝色急流(BJ)。短暂的向上喷流只传播几公里，在26公里以下终止，被称为蓝色启动器(BS)，而所谓的巨大蓝色喷流(GBJ)传播到中间层/低电离层。人们普遍认为，北京？S是由雷雨中的向上传播领袖产生的。一些人试图描述领导者的形成，包括最近的双极BJ模型。然而，尽管对这一复杂现象的理论理解取得了实质性进展，但仍存在重大困惑。事实上，仍有两个悬而未决的问题尚未解决，这两个问题都与实验室领导有关，也与闪电形成的领导有关。也就是说，是哪种机制控制了引导器的低传播速度，以及引导器流光区的自洽电场是如何形成的。这项研究将重点放在蓝色喷气机/蓝色启动器/巨大蓝色喷气式飞机的定量建模上。它将结合两个主要模型，第一个是电流收缩的解析和数值研究，它决定了流光闪光向引导者的转变，并决定了北京卫视S的慢传播速度。第二个模型是决定BJ形成的引导者流光区内一组流光形成的平均电场模型。理论研究将得到可用于验证现有模型的桌面实验的补充。地面和卫星上的光学和紫外线观测将试图验证模型的预测。了解BJ/BS/GBJ的物理学不仅是一个前沿科学问题，而且可以提供一种电离层和平流层之间直接瞬时耦合的机制，这对全球电路有影响。潜在的应用包括：通过将我们的模型应用于流光和引线击穿的实验室实验，扩展气体放电和弱电离等离子体物理学的基本知识，并通过对电流收缩的定量理解，影响强大激光和等离子体化学反应器的设计。该计划将支持马里兰大学学生在这一多学科领域的教育和培训，结合理论和计算等离子体物理以及气体动力学的方面。这项研究将促进学术界和产业界之间的合作。它还涉及普林斯顿大学、马里兰大学和俄罗斯科学院顶尖科学家之间的广泛国际合作。

Narrow cones of blue light that propagate upward from the top of a thundercloud were discovered during the Sprites94 aircraft campaign. Two types of blue jets (BJ) have been observed. The brief upward jets, which propagate only a few km and terminate below 26 km, were dubbed blue starters (BS), while so-called gigantic blue jets (GBJ) propagate into the mesosphere/lower ionosphere. It is widely accepted that BJ?s are produced by an upward propagating leader from thunderstorms. Some attempts have been made to describe the leader formation, including recent model of bipolar BJ. However, despite substantial progress in the theoretical understanding of this complicated phenomenon, significant puzzles remain. In fact, two outstanding problems are still unresolved and both are relevant to the laboratory leaders, as well as to the leaders formed by lightning. Namely, which mechanism governs the low propagation velocity of the leader, and how a self-consistent electric field in the streamer zone of a leader is formed. This research will focus on quantitative modeling of Blue Jets/Blue Starters/Gigantic Blue Jets. It will combine two major models, the first is an analytical and numerical study of current contraction, which determines transformation of a streamer flash into a leader, and which governs slow propagation velocity of BJ?s. The second is a model of the average electric field formed by a group of streamers in the streamer zone of a leader, which determines the BJ formation. The theoretical study will be complemented by the table top experiments that could be used for validation of the existing models. The ground based and satellite-borne optical and ultraviolet observations will attempt to validate the model predictions. Understanding the physics of BJ/BS/GBJ is not only a frontier scientific topic, but it could provide a mechanism for direct transient coupling between the ionosphere and stratosphere with implication to the global electric circuit. Potential applications include: extending fundamental knowledge in the physics of gas discharge and weakly ionized plasma by applying our model to laboratory experiments of streamer and leader breakdown, and influencing the design of powerful lasers and plasma chemical reactors through a quantitative understanding of current contraction. The program will support the education and training of the University of Maryland students in this multidisciplinary field, combining aspects of theoretical and computational plasma physics as well as gas dynamics. The study will promote collaboration between the academia and industry. It also involves broad international collaboration between Princeton University, the University of Maryland, and leading scientists from the Russian Academy of Sciences.