磁层喷射在太阳周期24上:一个经验模型
Laura Vuorinen1, Adrian T LaMoury2, Heli Hietala1,2,3
1Department of Physics and Astronomy University of Turku Turku Finland.
Journal of geophysical research. Space physics
|March 5, 2024
概括
使用THEMIS数据,在一个太阳周期中研究了磁层喷流,即增强压力的流动. 发生率并不强烈依赖于太阳周期变化,尽管初始采样偏差.
科学领域:
- 空间物理 空间物理
- 太阳地球物理 太阳地球物理
- 磁层动力学 磁层动力学
背景情况:
- 超级风暴期间事件和宏观相互作用的时间历史 (THEMIS) 任务提供了来自太阳底磁层的大量数据.
- 了解依赖于太阳风条件的现象,需要进行一致的太阳风采样.
- 磁层喷流的特点是向地球增强的动态压力,受到太阳风参数的影响.
研究的目的:
- 为了研究磁层喷流在整个太阳周期中的发生率 (24).
- 为了解决THEMIS数据中的偏差,由于航天器轨道和不均的太阳风采样.
- 开发基于太阳风条件的喷气发生模型,并估计无偏的年率.
主要方法:
- 2008-2019年THEMIS航天器在太阳底磁层中的观测结果的分析.
- 喷气发生与太阳风条件的相关性,特别是行星间磁场的方向.
- 基于太阳风参数的喷气发生预测模型的开发.
- 使用OMNI数据计算太阳周期24和23的无偏的年度喷气发生率.
主要成果:
- 发现THEMIS记录的磁层喷流的年度发生率是有偏见的.
- 开发了一个模型,根据太阳风的条件来预测喷气事件的发生.
- 无偏见的分析表明,磁层喷射形成中没有强烈的太阳周期依赖.
- 喷射主要是在近平行弓冲击的下游观察到的.
结论:
- 磁层喷射发生的THEMIS初始观测因采样不一致而产生偏差.
- 磁层喷射形成并没有强烈依赖太阳周期阶段.
- 太阳风条件,特别是国际货币基金组织的方向,是喷气事件的关键驱动因素.
- 进一步的研究可以完善对喷气动力学及其对磁层的影响的理解.
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