Research On Quasi-elastodynamic Model Of Magnetopause

Some explosive activities caused by the interaction between the solar wind and the magnetosphere will affect human aerospace,communications,navigation and national security,and threaten human health.Understanding the solar wind-magnetosphere interaction is a key frontier subject of space physics and one of the important research contents of space weather.Studying the response of the magnetopause position to solar wind changes is an important part of understanding the interaction between the two.Thanks to the vigorous development of satellite observation and computer technology,the study of magnetopause models has made great progress so far.Traditional magnetopause model believes that one can uniquely determine the position of the magnetopause in certain solar wind and geomagnetic field conditions,which is inconsistent with the results of satellite observations.As for how the magnetopause responds to changes in the solar wind is not yet fully understood.The underlying physical mechanism of magnetopause's motion still needs to be further studied.In order to explore the dynamic process of the solar wind-magnetosphere interaction and establish a magnetopause model closer to its physical nature,a quasi-elastic dynamics model of the magnetopause based on satellite data is proposed for the first time,and this model is used to explain the characteristics of magnetopause's movement,and finds that the new model shows certain advantages over the traditional models.Based on the view that the compression-recovery process of the magnetopause is a kind of quasi-elastodynamic behavior,combined with the theory of elastodynamics,the solar wind-magnetosphere interaction is modeled.The compression-recovery process of the magnetopause is similar to the elastic dynamic behavior of the spring compression-recovery process,but it contains energy dissipation and conversion process,that is,the motion of the magnetopause is a kind of quasi-elastic dynamics.In this paper,combined with the theory of elasto-dynamics,a quasi-elastodynamic model of the magnetopause is built.Compared with previous work,this model can explain the characteristics of the periodic vibration of the magnetopause,it shows certain superiority over traditional static models.The dynamic process of the magnetopause is analyzed using numerical analysis,and the physical meaning contained in the dynamic process of the magnetopause is analyzed by introducing and adjusting parameter.The model is used to analyze the general relationship between the dynamics of the magnetopause and the changes in solar wind dynamic pressure,the north-south component of the interplanetary magnetic field,it explores the relationship between the dynamics of the magnetopause and the changes in the solar wind,reveals the basic characteristics of the quasi-elastodynamic process and persues the physical nature of the magnetopause's motion.Combined with satellite observation data,the new model established is applied to predict the dynamic process of the magnetopause in real conditions.18,935 magnetopause crossing events of the THEMIS satellite from 2007 to 2020 and the OMNI solar wind data corresponding to these magnetopause crossing events are obtained and the model is used to predict the dynamic process of the magnetopause.The final results show that the established model has a higher prediction success rate and a smaller prediction deviation rate than the Shue98 and T96 model.