Magnetohydrodynamic simulation of interaction between the solar-wind magnetosphere, and ionosphere

我们建立了一个自洽处理太阳风-磁层-电离层相互作用的三维全球磁流体力学模型，并研究了其传输过程。近几个小时来，太阳风和行星际磁场的变化强烈地影响着地球磁层的形态和动力学。磁层上的直接驱动过程，如极电势，大约在10分钟内对其变化作出响应，另一方面，等离子体片中的加卸载过程，如等离子体片中尾部重联的开始，通常需要从IMF的突然南转起大约1小时的时间延迟。因此，为了获得未来的磁层结构，有必要知道当前的磁层结构以及太阳风和IMF的当前参数。为了将电离层反馈过程包括到全球mhd si…更多地模拟太阳风-磁层相互作用，传统地将场向电流从磁层内边界映射到电离层，通过计入电离层电导率来计算极地电离层中的电势，然后将对流电场反向映射到内部磁层。我们在全球MHD模拟中尝试了相反的过程。我们对太阳风和地球磁层之间的相互作用进行了三维全球MHD模拟，以研究1996年11月17日的事件和1999年3月19-20日的空间天气“电喷流挑战”事件。作为模拟的输入，利用了来自WIND和ACE卫星的1分钟太阳风参数，即太阳风速的x分量、太阳风密度、等离子体气压以及太阳-磁层坐标下IMF的y分量和z分量。为了与卫星和SuperDARN的观测结果进行比较，我们每10分钟给出了正午-午夜和赤道面的能量横截面分布、电离层电位的极图和磁力线的配置。较少

We have constructed a 3-dimensional global magnetohydrodynamic (MHD) model to self-consistently treat the solar wind-magnetosphere-ionosphere interaction, and have studied the transfer processes. Configuration and dynamics of the earth's magnetosphere are strongly affected by variations of the solar wind and interplanetary magnetic field (IMF) for recent several hours. Directly driven process on the magnetosphere like a polar electric potential responds in about 10 minutes to their variations, on the other hand loading-unloading precess like onset of tail reconnection in the plasma sheet usually needs about 1 hour time delay from sudden southward turn of IMF.Therefore, it is necessary to know the present magnetospheric configuration as well as the present parameters of the solar wind and IMF in order to obtain future magnetospheric configuration.Magnetosphere and ionosphere coupling is one of important processes. In order to include the ionospheric feedback process to the global MHD si … More mulation of the solar wind-magnetosphere interaction, field aligned currents are traditionally mapped from the inner boundary of magnetosphere onto the ionosphere, electric potential is calculated in the polar ionosphere by including ionospheric conductivity, and then convective electric fields are reversely mapped to the inner magnetosphere. We have tried the opposite procedure in our global MHD simulation.A 3-dimensional global MHD simulation of the interaction between the solar wind and the earth's magnetosphere has been executed to study the event of November 17, 1996 and the space weather "electrojet challenge" event of March 19-20, 1999. As input for the simulation, one minute values of solar wind parameters from the WIND and ACE satellites were utilized, namely the x-component of the solar wind velocity, the solar wind density, the plasma pressure and the y-and z-components of the IMF in solar-magnetospheric coordinates. We presented cross sectional profiles of energy in the noon-midnight and equatorial planes, polar plots of ionospheric potential and configuration of magnetic field lines every 10 minutes to compare with the satellite and SuperDARN observations. Less