Quantifying the Global Spatial and Temporal Behavior of Kinetic Alfven Waves in the Auroral Zone

阿尔芬波已经在许多天文等离子体中被发现，例如太阳和太阳系的其他行星。这些是磁流体波，它们在磁层内携带能量，并为粒子提供能量。它们对于理解磁层和电离层之间的边界和产生极光至关重要。该项目是对这一过程的详细研究，这对预测和准备空间天气影响很重要。这个项目研究了动力学阿尔芬波(KAW)在磁层-电离层耦合中的作用。这项工作将侧重于利用叠加的历元分析、亚暴爆发列表和地磁指数对多年卫星数据进行统计和观测研究，以便将观测与具体的地磁条件联系起来。目标是回答以下问题：(1)在不同的地磁条件下(声发射指数、亚暴、风暴)？(2)在亚风暴和风暴的不同阶段，KAW的全球分布和总功率的时间演变是什么？(3)KAW对阿尔芬波预算(包括MHD制度)的贡献是什么？(4)它们在AAR上方的M-I耦合中与AAR以下的Alfvenic观测和来自发电机区域的意义是什么？该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Alfven waves have been discovered in many astronomical plasmas, such as the Sun and other planets of the solar system. These are magnetohydrodynamic waves that carry energy inside the magnetosphere and energize particles. They are crucial in understanding the boundary between the magnetosphere and ionosphere and in producing the aurora. This project is a detailed study of this process which is important for predicting and preparing for space weather effects. Graduate students will also be supported in research.This project studies the role of kinetic Alfven waves (KAW) in magnetosphere-ionosphere coupling. The work will focus on a statistical, observational study of multi-year satellite data using superposed epoch analysis, substorm onset lists, and geomagnetic indices for relating the observations to specific geomagnetic conditions. The goals are to answer the following: (1) What is the global spatial distribution and total power of KAW above the auroral acceleration region (AAR) under various geomagnetic conditions (AE index, substorm, storm)? (2) What is the temporal evolution of the global distribution and total power of KAW during different phases of substorms and storms and as a function of time? (3) What is the contribution of KAW to the Alfven wave budget (including MHD regime)? (4) What is their significance in the M-I coupling above the AAR in relation to Alfvenic observations below the AAR and from the generator region?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.