Extraction and Transport to the Magnetosphere of Solar Wind Energy during Periods of Low Mach Number Solar Wind Flow

了解空间天气的影响，地球周围磁等离子体环境的变化，依赖于我们如何测量极端条件的基本定义。地磁风暴代表了我们当地地球空间环境的极端情况，代表了我们国家天基资产（国防和商业卫星）最脆弱的时候。这项工作将通过使用空间环境观测数据集和基于物理学的模型，确定哪些条件会导致极端空间天气。更广泛的影响包括了解极端条件下的空间天气条件（国家空间气象行动计划中规定的优先事项），并在西班牙裔服务机构培训学生和博士后研究。该项目根据总体风暴能量学开发了一种新的地磁风暴分类，重点是在电离层中耗散大量能量的风暴，在电离层中，这种活动可能产生重大的空间气象后果。将选择一组事件，这些事件将代表最具活力的风暴，包括在低马赫数太阳风流动条件下发生的“超级风暴”。这些事件将使用数据和模拟（全球磁流体模型运行与环电流模块）进行研究，以确定能量转移到地球空间系统的控制因素。这项研究的目标是创建一个全面的概念模型，解释在大磁暴特征的相对低的太阳风马赫数期间，入射到磁层的太阳风能量如何转移到电离层和磁层。该研究还将确定目前的全球模型在多大程度上能够捕捉到这种转移的基本物理特性，并确定可能缺失的物理特性领域，这些领域可能有助于模型和数据之间更好的对应。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Understanding the impacts of space weather, changes in the magnetic plasma environment surrounding the Earth, relies on basic definitions of how we measure extreme conditions. Geomagnetic storms represent the extremes of our local geospace environment and represent times when our national space-based assets (satellites for defense and commerce) are most vulnerable. This work will determine what conditions lead to extreme space weather through use of observational datasets and physics-based models of the space environment. The broader impacts include understanding space weather conditions during extreme conditions (a priority set out in the National Space Weather Action Plan) and training students and a post-doc on research in a Hispanic Serving Institution.This project develops a new classification of geomagnetic storms based on overall storm energetics, with an emphasis on storms with large amounts of power dissipated in the ionosphere where the activity can have significant space weather consequences. A set of events will be selected that will represent the most energetic storms, including "superstorms" that occur under conditions of low Mach number solar wind flow. These events will be studied using both data and simulations (global MHD models run with and without a ring current module) to determine the controlling factors for energy transfer to the geospace system. The goal of this research is to create a comprehensive conceptual model that explains how the solar wind energy incident on the magnetosphere is transferred to the ionosphere and magnetosphere during periods of the relatively low solar wind Mach number that characterize large magnetic storms. The research will also identify to what extent current global models can capture the essential physics of that transfer and identify possible areas of missing physics that could contribute to a better correspondence between models and data.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.