Studies Of Dynamic Processes Of Magnetic Plasma In The Solar Atmosphere

The sun is not only the nearest star to our earth,but also the only star that can be observed closely.It can provide valuable data for understanding the star and the behavior of plasma in the extreme space condition.The same as many other celestial bodies,the sun also coats a thick layer of atmosphere that is the so called solar atmosphere.There is plenty of evidence indicating that solar atmosphere is always in a highly dynamic state.There are various dynamic processes in anywhere of solar atmosphere at all times.These dynamic processes are not only closely related to the space weather,but have also an intimate relationship with the geomagnetic field and the global climate.Therefore,they have been one of the hottest topic in solar physics.There are different kinds of solar activities with different temporal and s-patial scales in solar atmosphere,including different kinds of waves,mass flows and rapid energy release processes.They are essentially different dynamic pro-cesses of solar atmosphere.The observed solar active events usually consist of several dynamic processes.To better understand the physics and dynamics of solar atmosphere,details about these dynamic processes are inevitably required.However,because of the limitation of our observation and the complexity of solar atmosphere itself,there are many problem about the dynamic processes keeping unclear so far.For further understanding the dynamic processes in so-lar atmosphere,a combination of observational and theoretical efforts is highly encouraged.Based on observations from both space and ground-based telescopes,we have a detailed analysis to several dynamic processes in solar atmosphere.Firstly,we present a clear observation of distinct different oscillations in some neighboring coronal loops,from which we find for the first time that significantly different oscillations can be excited in neighboring loops simultaneously.Further analysis reveals that the oscillations may be dominated by different harmonics,respec-tively.It also shows that each harmonic has its own amplitude distribution.All the characteristics strongly suggest that multiple harmonics with different amplitude distributions can be excited simultaneously by the same flare even in neighboring loops.Moreover,the investigation of oscillation in the single loop demonstrates that the oscillation has different phases in the different parts of the loop:it shows a decay phase in the part away from the triggering flare and a growing phase in the other part that is near the flare,we call it the asym-metric loop oscillation.Since the oscillating loop has a nearly symmetric shape,we propose that the asymmetric oscillation should be caused by the asymmetric excitation.Within this framework,we propose a possible model for this type of asymmetric oscillation.According to the model,the asymmetric excitation generates an asymmetric oscillation because it provide an asymmetric normal component of impact.The asymmetric oscillation has an asymmetric energy dis-tribution and the energy flows from high-energy part to low-energy part leading to the observed phenomenon.According to the existing observation,we have also done some theoretical researches on waves in solar atmosphere.The researches mainly contribute to three problems:the effect of magnetic and density differences on the fast kink oscillations of neighboring loops,the frequency shift of fast kink oscillation caused by the density changing of coronal loops and the propagating solution of elastic waves in inhomogeneous media.From the researches,we derive the dependence of period and amplitude of fast kink oscillations on the loop properties in an identical excitation,which provides a theoretical basis for detecting the physical divergences between neighboring loops by only using their different oscillations.In addition,we also derive the dependence of frequency of fast kink oscillations on the density fluctuation of coronal loops,which improves our acknowledge on the frequency shift of fast kink oscillations and provides accordance for correcting the effect of density changing on the oscillatory amplitude.Besides that,we also discussed the propagation properties of general elastic waves in an inhomogeneous media,obtained the analytical solutions of several special conditions and explored the discrete medium model.All of these significantly enrich the content of coronal seismology and provide valuable references for the further study on waves in solar atmosphere.Moreover,by using the New Vacuum Solar Telescope in Fuxian lake,we observed the mass flows of a quite solar prominence.From the observation,two types of mass flow can be identified in different parts of the observed prominence:the material primarily has a circular motion and a downward motion separately in the middle section and legs of the prominence,which creates a piecewise mass flow along the observed prominence.A clear interface can also be identified between the two types of mass flow.A detailed analysis of the middle circular mass flow indicates that the prominence has a slight deformation as the material flows through it.By combining the magnetic structure and the inhomogeneous radiation of the prominence,we suggest that the different mass flows should be caused by the different oriented magnetic field and inhomogeneous physical conditions of the prominence.This investigation also demonstrates that the mass flow can reflect to some extent the inner structure of the prominence,which may shield more light on the internal structure and dynamics of solar prominences.As the other situation of the disturbance in solar atmosphere,the rapid en-ergy release processes are far more attractive.Here we also present an analysis of the rapid energy release processes within a confined filament eruption.It clearly shows that a second energy release process can be excited in the confine mag-netic arcades of the eruptive filament system by its eruption.The quantitative analysis has also been implemented.The result shows that the energy releases are distinctly different from those observed in successful eruption.Most of the characteristics of the processes are well consist with the chain Taylor relaxation predicted by Tam(2015).All of these give us many implications on theories of the energy release processes in confined filament eruptions.