Tomographic Inversion Of The Ring Current Ion Mode And Ion Distribution

The terrestrial ring current is one important part of the magnetosphere currents.Changes in this current are responsible for global decreases in the Earth's surfacemagnetic field, which are known as geomagnetic storms. There has been a widerinterest in ring current's ions properties and simulations for its effect on the storm andsubstorm etc. For above, we divide our work into three parts.(1) We modified the experiential model of ring current ions and simulated theflux distribution of ring current ions. Then we use observation results of Cluster toprove the model's feasibility.(2) We calculated the position of ENA source observed by NUADU/TC-2.(4) We inversed the ring current ions distribution by the technique of seismictomograpy.In the first part of the article, we modified Shen chao and Liu zhen-xing's ringcurrent ions model during mainphase of storm. Compared with the observations ofCluster, we have the follow results: we append the factor of loss cone and cause ionslost in atmosphere. We modified the loss coefficient in the simulation, and foundasymmetry between dayside and night of the distribution of ring current. 10-30 keVions of simulated results are accordant with the observations of CIS on board Cluster.So the model is feasible.In the second part of our research, we use geometrical method to calculate theposition of center and boundary points of ENA source. We suppose that in a short time,satellite observed the same ENA source structure, we can confirm the position of thecenter and the boundary points of ENA source by analysis the data of satellite indifferent positions.The third part of our work is for the inversion problem of ring current ions. Weexplore a new technique and arithmetic to inverse the ring current ions distribution.We induct the technique of seismic tomograpy into our inversion. Based on thetechnique, we take the ring current region of magnetosphere space into grids and useAlgebraic Reconstruction Techniques to extract ion's flux distribution from the ENAimage. Inversion distribution consistent with original one identified the feasibility ofthis technique.