Field-Aligned Current Observation During The Substorms

Geomagnetic storm and substorms are the basic processes of magnetospheric dynamics,which are processes of energy input,coupling and dissipation in geospatial space.The coupling between the magnetosphere and the ionosphere is an important physical process during the substorms.It is of important theoretical significance for its in-depth analyze and research,and for space weather prediction.The current system in the magnetosphere is the basic structure of the transport of energy materials.The in-depth analysis of the current system architecture is of great significance for revealing the substorms mechanism of the magnetosphere.This study is divided into three parts.The first part covers the first two chapters.The first chapter briefly introduces the substorms phenomenon and current system.The second chapter explains the satellite plan involved and introduces the multi-point satellite detection method.The second part discusses the changes of current system and plasma composition in the magnetosphere during substorms;the third part studies the ion composition in the magnetotail plasma sheet.This study used the multi-satellite exploration program,the MMS satellite program and the Swarm satellite program.These program provide high-quality detection data.This study analysis the magnetospheric current system,the composition of the near-magnetic tail plasma and plasma's distribution characteristics.It is found that the field-aligned current has a significant coupling relationship around the equatorial plane and the high-latitude auroral region.The observation shows that the field-direction current in the region II and the ring current are connected.In addition,we have found that there is a void region where the plasma density is low in magnetosphere.Finally,we observed the composition of the magnetotail plasma sheet,and obtained that in the magnetic tail plasma sheet,the particles were affected by the substorms and the energy of the particles became high but there was no accumulation.The results of this study are important for understanding the energy conversion mechanism of the substorms,the structure of the global magnetospheric current system and the transport process of plasma in the magnetosphere.