Collaborative Research: Self-Organization of Vortices as a Contributing Mechanism for Tropical Cyclogenesis

热带气旋对生命和财产构成非常严重的威胁，并影响到地球仪许多地方的许多人。 因此，在更好地了解其结构和演变方面取得的进展有可能在若干层面上对社会产生直接影响。 对热带气旋的研究可以分为三类：运动、强度变化和成因。 在理解前一个过程方面取得了进展，但在更好地理解后两个过程方面取得的进展要小得多。 这项研究将涉及热带气旋成因的某些方面，并有可能大大提高有关热带气旋的科学知识和最终预测技能。其成因过程尚未有严格且普遍的定义，但大多数人都同意它包括各种事件，例如从中层涡旋形成低层涡旋，以及从冷核心结构形成暖核心热力学结构。 本研究将集中在涡合并在这些过程中的作用。 以前有许多研究强烈支持这样的观点，即多个较小的漩涡合并成一个较大的“母”漩涡是起源过程的关键部分。 然而，目前，合并过程如何影响所产生的母涡旋的具体结构的细节还没有得到很好的研究或记录。通过在二维湍流中独特地应用基于概率解的概念，这项工作将探索并记录一种预测由多个合并事件形成的母涡的确切结构的方法。 该方法预测母涡结构的基础上，单独的知识的组合循环和能量的小涡，形成它。该方法表明，某些配置的小涡将合并形成一个更小，更强烈的母涡比其他配置，具有相同的总环流。 这是一个重要的特征，因为母涡旋维持自身并进一步增强为初期热带气旋的能力在很大程度上取决于其结构。由于小尺度涡旋通常在积雨云集群内形成，因此可以在一定程度上进行远程测量，这项工作的结果可能会提供预测性的见解，哪些云团更有可能经历热带气旋。

Tropical cyclones pose a very significant threat to life and property, and affect many people in many places around the globe. Progress towards better understanding of their structure and evolution thus has the potential for directly impacting society on a number of levels. The study of tropical cyclones may arguably be separated into three categories: motion, intensity change, and genesis. Progress has been made toward understanding the former but measurably less progress has been made towards better understanding of the latter two processes. This research will address certain aspects of tropical cyclone genesis and has the potential to significantly advance scientific knowledge and ultimately predictive skills in regard to tropical cyclones. The genesis process is not yet rigorously and universally defined, but most would agree that it comprises a variety of events, such as formation of a low-level vortex from a mid-level vortex, and formation of a warm core thermodynamic structure from a cold core structure. This research will concentrate on the role of vortex merger in these processes. There have been a number of previous studies that strongly support the idea that the merger of multiple smaller vortices into a larger "parent" vortex is a key part of the genesis process. Presently, however, the details of how the merger process affects the specific structure of the resulting parent vortex have not been well studied or documented. By uniquely applying concepts based on probabilistic solutions in two dimensional turbulence, this work will explore and document a method for predicting the exact structure of a parent vortex formed by multiple merger events. The method predicts the parent vortex structure based solely on knowledge of the combined circulation and energy of the smaller vortices that formed it. The method demonstrates that certain configurations of small vortices will merge to form a smaller, more intense parent vortex than other configurations that have the same total circulation. This is an important feature since the ability of the parent vortex to maintain itself and intensify further into an incipient tropical cyclone can depend strongly on its structure. Since small-scale vortices are typically formed within clusters of cumulonimbi, and thus can be remotely measured to some degree, the results of this work might offer predictive insight into which cloud clusters have a better chance of undergoing tropical cyclogenesis.