| It is well known that the ionosphere is an important source of magnetospheric plasma, especially H+ ions and O+ ions, the high latitude ionosphere transport the high flux and low energy (hot) plasma to the magnetosphere, the whole quality is up to 1kg/ s-1. The effect of such high flux upflowing ions on the composition and the dynamic process of the magnetosphere is still unclear. The key problem is if the ions upflow can really trigger the substorm onset? A 3-D resistive MHD simulation is carried out to study the effect of the ions upflow on the dynamic process of the magnetotial and the triggering of the substorm onset. The whole work is divided into three parts: (1) The effects of the ions upflow original from the night-side auroral oval on the near-earth magnetotail during the quiet time; (2) The effect of the convection electric field on the dynamic process of the magnetotail, mainly on the substorm growth phase and the onset process; (3) The effect of the ions upflow presented during the substorm growth phase on the substorm process, the most interesting question is if the ions upflow can trigger the substorm onset. In the magnetotail, one of the most significant observational features at substorm onset is the sudden enhancement of the field-aligned current and an increase of the north-south component of the magnetic field (Bz) up to its dipolar value, so we especially analysis the change of the field-aligned current and the Bz in each part. The first part of the simulation is to understand the effects of the ions upflow original from the night-side auroral oval on the near-earth magnetotail during the quiet time. This is important for us to understand the current instability triggered by the upflows in the near earth region. The main conclusions include that: ·During the quiet time, the up-flowing ions original from the night-side auroral oval have effect mainly on the near-earth magnetotail. The effect of the upflow ions on the dynamic process of the magnetotail depends on the flux of the upions entered the plasma sheet. The main effects include: (1) with the entering of the upflowing ions, the pressure in the near-earth plasma sheet decrease; (2) the density of the plasma in the plasma sheet decrease; (3) the cross-tail current increase in the near-earth region, and decrease beyond 20Re in the plasma sheet; (4) the plasma flow in the plasma sheet is the earth-direction inside 20Re, and the tail-direction outside 20Re. This is important for us to understand the role of the upflowing ions on the substorm process. Inducing the enhancement of field-aligned current in the near-earth magnetotail. The distribution region of the FAC is mainly divieed into three regions, including: high-latitude region, mid-latitude region and plasma sheet boundary. The distribution of the FAC in the dark-aside and dawn-aside have reversal multi-layer structure, including low-latitude. The intensity of the FAC depends not only on the up-flowing ions energy flux transfer into the plasma sheet, but also on the velocity of the upflows. The second part of the simulation is to understand the substorm process under the effect of the convection electric field, and forming the thin current sheet in the magnetotail. The main conclusions include that: The convection electric field have important effects on the location of the X-line and the process of the substorm With the growth of the magnetic-island in the x and z direction, the plasmoid moved tail-ward, and the near-earth X line moved earth-ward fastly. The moving velocity of the X-line mainly depends on the convection electric field. With the earth-ward moving of the X-line, the significant symbol of the substorm is presented, including the thinning of the plasma sheet, the increasement of the cross-tail current and the forming of the thin current sheet in the near-earth magnetotail The third part is based on the results of the second part, and is mainly about the triggering of the current instability by the ions upflow original from the night-side auroral oval. This can induce the substorm onset during the late growth phase. The main conclusions include that:...
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