Koller Florian, Temmer Manuela, Preisser Luis, Plaschke Ferdinand, Geyer Paul, Jian Lan K, Roberts Owen W, Hietala Heli, LaMoury Adrian T
Institute of Physics University of Graz Graz Austria.
Space Research Institute Austrian Academy of Sciences Graz Austria.
J Geophys Res Space Phys. 2022 Apr;127(4):e2021JA030124. doi: 10.1029/2021JA030124. Epub 2022 Apr 8.
Magnetosheath jets constitute a significant coupling effect between the solar wind (SW) and the magnetosphere of the Earth. In order to investigate the effects and forecasting of these jets, we present the first-ever statistical study of the jet production during large-scale SW structures like coronal mass ejections (CMEs), stream interaction regions (SIRs) and high speed streams (HSSs). Magnetosheath data from Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft between January 2008 and December 2020 serve as measurement source for jet detection. Two different jet definitions were used to rule out statistical biases induced by our jet detection method. For the CME and SIR + HSS lists, we used lists provided by literature and expanded on incomplete lists using OMNI data to cover the time range of May 1996 to December 2020. We find that the number and total time of observed jets decrease when CME-sheaths hit the Earth. The number of jets is lower throughout the passing of the CME-magnetic ejecta (ME) and recovers quickly afterward. On the other hand, the number of jets increases during SIR and HSS phases. We discuss a few possibilities to explain these statistical results.
磁鞘射流构成了太阳风（SW）与地球磁层之间的一种重要耦合效应。为了研究这些射流的影响及预测，我们首次对诸如日冕物质抛射（CME）、流相互作用区域（SIR）和高速流（HSS）等大规模太阳风结构期间的射流产生进行了统计研究。2008年1月至2020年12月期间来自亚暴期间事件和宏观相互作用时间历史（THEMIS）航天器的磁鞘数据用作射流检测的测量源。使用了两种不同的射流定义来排除由我们的射流检测方法引起的统计偏差。对于CME和SIR + HSS列表，我们使用了文献提供的列表，并使用OMNI数据扩展了不完整的列表，以涵盖1996年5月至2020年12月的时间范围。我们发现，当CME磁鞘撞击地球时，观测到的射流数量和总时间会减少。在CME磁 ejecta（ME）通过期间，射流数量较低，之后迅速恢复。另一方面，在SIR和HSS阶段，射流数量会增加。我们讨论了几种解释这些统计结果的可能性。
