# Statistical Characterization of the Magnetic Field in Space during Magnetic Storms
## 1 Magnetic Storms  
When coronal mass ejections and high-speed solar winds caused by solar activity impact the magnetosphere, the geomagnetic field will change drastically in a short period of time, thus causing magnetic storms [1; 2; 3]. The generation of magnetic storms will affect satellites in orbit and lead to satellite crashes, such as the one that occurred on 8 February 2022 at SpaceX, where 40 of a chain of 49 satellites were affected by magnetic storms and crashed [4]. Moreover, for the communication system, if the solar storm is too strong, it will damage the ground communication system and severely distort the signal, affecting the communication quality or even causing communication interruptions [5; 6]. The violent geomagnetic perturbations can lead to navigation and positioning problems [7]. The key factor that leads to the generation of magnetic storms is the presence of a strong southward component of the interplanetary magnetic field over a long duration. Magnetic storms are accompanied by violent perturbations of the near-Earth space environment and are among the most important events in space environment forecasting. The Magnetic storm ring current index (Dst index) is the result of averaging the hourly geomagnetic horizontal perturbation values of four geomagnetic stations near the Earth's equator at approximately uniform longitude intervals with a certain weighting. Notably, values of Dstmin \(\geq-19\) nT, \(-20\) nT \(\geq\) Dstmin \(\geq-49\) nT, \(-50\) nT \(\geq\) Dstmin \(\geq-99\) nT, \(-100\) nT \(\geq\) Dstmin \(\geq-249\) nT, and \(-250\) nT \(\geq\) Dstmin represent magnetic calm periods, small magnetic storms, moderate magnetic storms, strong magnetic storms, and super magnetic storms, respectively. Themagnetic storms selected in the paper are medium-large and strong magnetic storms that occurred from 2016 to 2021 with \(-80\) nT \(\geq\) Dstmin. In this paper, six magnetic storm events were selected for analysis for storms occurring from 00:00 on 6 March 2016, to 23:00 on 7 March 2016; 00:00 on 13 October 2016, to 23:00 on 15 October 2016; 01:00 on 27 May 2017, to 23:00 on 28 May 2017; 0:00 on 8 September 2017, to 23:00 on 9 September 2017; 00:00 on 27 September 2020, to 23:00 on 28 September 2020; and 00:00 on 4 November 2021, to 23:00 on 5 November 2021. Figure 1 shows the magnetic field components Bx, By, and Bx for these time periods and the Dst index. In many of the previous studies on magnetic storms, authors used to focus on solar wind-magneto sphere interaction during magnetic storms, such as large-scale magnetopause reconnection [8; 9; 10], the time evolution of Dst [11], the seasonal and solar-cycle distribution of storms [12], as well as relationships of storms and substorms [13; 14; 15]. However, in the field of signal processing, it is the statistical characteristics of the environment, rather than the time distribution and interaction of the magnetic storms and other factors, that determine the feature of the channels, which do have an effect on the signals. Figure 1: _Cont._  
Therefore, this paper focuses on the statistical characteristics of the space channel during the occurrence of magnetic storms, which are of great importance to signal analysis for Spaceborne equipment. By analyzing the observed data for each component of the magnetic field for six magnetic storms from 2016-2021, the statistical characteristics of the space magnetic field during magnetic storms, including probability density function, autocorrelation function, and power spectrum, could be obtained. The Dst index used  
Figure 1: Time-domain plot for Dst and components of the magnetic field.