Study Of Wave-Wave/Particles Interactions With Whistler-mode Waves Excitation In Important Structures In The Magnetosphere Space Environment

The near-Earth space environment is an area that has a very important impact on the earth’s ecosystem.It is related to the safety of life on earth,human survival activities,and technological development.Whistler-mode wave is a common right-handed circularly polarized electromagnetic wave in the near-earth space environment.The excitation of whistler-mode waves and related interaction process will change the parameters affecting and play an important role in the change of the near-Earth space environment,which is not only related to tsunamis,earthquakes,volcanic eruptions,and lightning.It is related to catastrophic events such as weather,and has a significant impact on scientific and technological aspects such as resource exploration,aerospace,positioning,and communication.Grasping the environmental changes in the near-Earth space helps to establish a scientific basis for the prediction of changes in the global environmental system,and can provide a more scientific implementation basis for the scientific management of the Earth system.In order to gain an in-depth understanding of the interaction process in the magnetospheric region of the near-Earth space environment accompanied by whistle-wave excitation,this doctoral dissertation has carried out the following researches:Study about the modulation of whistler-mode waves by ultra-low frequency wave in a macroscale magnetic hole in the magnetopause.In this study,we use the Magnetospheric Multiscale(MMS)mission data to study the modulation relationship between ultra-low frequency waves and whistler-mode waves in macroscale magnetic holes in the Earth’s magnetopause,and demonstrate for the first time that the butterflyshaped electron pitch angle distribution can excite whistler-mode waves.We observed a macroscale magnetic hole near the magnetopause.There are obvious low-frequency fluctuations in the magnetic hole,the frequency of which is slightly lower than the ion cyclotron frequency.Inside the magnetic hole,the plasma density increases and the temperature exhibits anisotropy.The ion vertical temperature is greater than the parallel temperature,and the electron parallel temperature is greater than the vertical temperature.In addition,a series of quasi-periodic whistler-mode waves were also observed in the magnetic hole,corresponding to the butterfly electron pitch angle distribution.By comparing the low-frequency wave and the whistler-mode waves,we found that there is a certain correspondence between the whistler-mode waves and the low-frequency wave,indicating that the low-frequency wave has a modulating effect on the whistler-mode waves in the magnetic hole.Study about whistler-mode waves and electrostatic wave near dipolarization front in burst bulk flow in the magnetotail.Using the MMS mission data,we observed a small-scale dipolarization front in the center of the burst bulk flow in the magnetotail,and continuously observed whistler-mode waves and electrostatic wave in different regions near the dipolarization front.And it is proved that these two kinds of waves are generated in different plasma environments.At the leading part of the burst bulk flow,the intense whistler-mode waves were observed inside the ion mirror-mode-mode structures,which should be excited by the perpendicular temperature anisotropy of trapping electrons.A small-scale dipolarization front was then observed at the center of this burst bulk flow as a boundary between the leading and trailing parts of the burst bulk flow.Behind the dipolarization front,both ion mirror-mode mode structure and whistler-mode waves become disappeared,while the large-amplitude electrostatic wave was detected,and is excited by the ion beam instability caused by the interaction of cold ions from the inner magnetosphere and hot ions from the reconnection outflow region.Study about whistler-mode waves in magnetic flux rope of magnetotail.In this study,based on MMS data,the ion mirror-mode structures were first observed inside magnetic flux rope in the magnetotail.Through the calculation of local electron acceleration,we found that these mirror-mode structures were generated in the Fermi acceleration region inside the magnetic flux rope.The trapping of electrons prevents electrons from escaping along the axis of the magnetic flux rope.This observation provides a possible mechanism for electron acceleration in magnetic flux ropes.At the same time,we observed the whistler-mode waves in the mirror-mode structure and confirmed that they were locally excited,so we speculate that the whistler-mode waves may provide scattering for the trapped electrons.Statistical characteristics of bump-on-tail(BOT)electron energy spectra associated with plasmaspheric hiss.Based on the observation data of the VAP-A satellite in the plasmasphere from 2013-2018,we study the spatial distribution and characteristic changes of the hiss waves and BOT energy spectrum,and counts the hiss wave and BOT distributions under different parameter classifications.The results quantify the strong correlation between the plasmaspheric hiss and BOT energy spectra,and show that the plasmaspheric hiss has a direct effect on the generation and ratio of BOT energy spectra.