Solar Cycle, Solar Wind, and Ultraviolet (UV) Control of Substorm Frequency and Magnitude

磁层亚暴是磁层物理学中研究最广泛、最重要的课题之一。亚暴是经常发生的现象，对亚暴的研究使研究人员能够研究太阳风、磁层和电离层系统动力学的基本物理。众所周知，在绝大多数亚暴中，磁重联发生在日侧磁层顶，通常被认为是质量、动量和能量从太阳风传输到磁层的主要方式。然而，其他过程也可以影响亚风暴动力学。这是一项评估太阳风速和电离层电导率对亚暴动力学的重要性的建议。由于SuperMAG项目创建了30年的大型数据库，因此有可能将这些影响与重新连接的影响分开。在亚暴中，磁层首先受到太阳风的影响。这种预适应有两个时标。在这个提议中，假设这些时间尺度受到太阳风速的影响。一种影响日侧磁层顶的重联率，另一种影响提供种子能量。到血浆片上。研究人员还建议通过研究太阳紫外线辐射的影响来研究电离层电导率对亚暴预适应的影响。特别是，他们将调查地磁活动每半年一次的变化，在春分时达到最大活动，并观察到在亚暴期间，冬半球会出现更强烈的极光。他们提出要解决的问题是，是偶极倾斜(并因此重新连接)导致了赤道分差，还是紫外线辐射也很重要。这项工作将支持一位刚刚开始职业生涯的年轻女科学家。应用物理实验室有一个持续的项目来支持暑期实习生。这项研究的数据库将对整个磁层物理工作非常有价值。

Magnetospheric substorms are one of the most widely studied and important topics in magnetospheric physics. Substorms are frequent and studies of substorms allow researchers to investigate the basic physics of the dynamics of the solar wind, magnetosphere and ionosphere system. It is well recognized that magnetic reconnection occurs at the dayside magnetopause in the overwhelming majority of substorms and is generally thought to be the main way in which mass, momentum and energy are transported from the solar wind to the magnetosphere. However, other processes can also influence substorm dynamics. This is a proposal to evaluate the importance of the solar wind velocity and ionospheric conductivity on substorm dynamics. It is possible to separate these effects from the effects of reconnection because of the large 30 year data base created by the SuperMAG project. In a substorm the magnetosphere is first preconditioned by the solar wind. This preconditioning has two time scales. In this proposal it is hypothesized that those time scales are influenced by the solar wind velocity. One influence affects the reconnection rate at the dayside magnetopause and the other provides ?seed energy? to the plasma sheet. The investigators also propose to investigate the influence of ionospheric conductivity on substorm preconditioning by studying the effects of solar UV insolation. In particular they will investigate the semi-annual variation of geomagnetic activity with peak activity at the equinoxes and the observation that during substorms stronger auroras occur in the winter hemisphere. They propose to resolve the question of whether dipole tilt (and hence reconnection) drives the equinoctial variation or whether UV insolation is also important. This work will support a young woman scientist just starting her career. The Applied Physics Laboratory has an ongoing program to support summer interns. The database from this study will be very valuable to the overall magnetospheric physics effort.