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，比如太阳和太阳系的其他行星。这些是磁流体动力波，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界限以及极光的产生至关重要。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非常重要。研究生也将在研究方面得到支持。本项目研究了动态阿尔芬波（KAW）在磁层-电离层耦合中的作用。这项工作将侧重于对多年卫星数据进行统计和观测研究，使用叠加历元分析、亚风暴发作表和地磁指数，将观测结果与特定的地磁条件联系起来。(1)在不同地磁条件下（声发射指数、亚暴、风暴），全球极光加速区（AAR）上空KAW的空间分布和总功率是怎样的？(2)在亚暴和风暴的不同阶段，KAW的全球分布和总功率随时间的变化是怎样的？(3) KAW对Alfven波浪预算（包括MHD制度）的贡献是什么？(4)它们在AAR上方的M-I耦合中，相对于AAR下方的Alfvenic观测值和来自发生器区域的观测值有什么意义？该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.