Data of 3D PPMLR-MHD model Simulation for manuscript "Formation and Evolution of Nightside Transpolar arc and Its Relationship with Energetic Plasma in the Magnetotail Lobe"

Data of 3D PPMLR-MHD model Simulation for manuscript "Formation and Evolution of Nightside Transpolar arc and Its Relationship with Energetic Plasma in the Magnetotail Lobe" These data come from a fully run of a 3D MHD Simulation model that is named PPMLR-MHD model (detailed descriptions below). There are 2 types of data files: 1) X15dXXXX.mat is saved simulation parameters. 2) Xing15XXXX_heatflux.mat is saved heat flux from simulation parameters. XXXX is the number of files, and files with the same serial number correspond to the same time. The first type files of data include the following parameters: time, x, y, z, logrho, Vx, Vy, Vz, Bx, By, Bz, Pr, Jx, Jy, Jz Where, time is simulation time, which need to plus the start time to transfer them to universal time: time+16:00. (x,y,z) are the three components of the position of simulation point in GSM coordinates; logrho is the plasma density at the simulation point; (Vx, Vy,Vz) are the three components of plasma velocity at the simulation point in GSM coordinates; (Bx, By,Bz) are the three components of magnetic field at the simulation point in GSM coordinates; Pr is the plasma dynamic presure at the simulation point; (Jx, Jy,Jz) are the three components of plasma electric current at the simulation point in GSM coordinates; The second type file of data includes the simulated heat flux along the magnetic field lines at the simulation point in GSM coordinates. PPMLR-MHD model The PPMLR-MHD model is on the basis of an extension of the piecewise parabolic method (1) with a Lagrangian remap to magnetohydrodynamics (MHD) (2, 3). It is a three-dimensional MHD model, designed specially for the solar wind–magnetosphere–ionosphere system (4-6). The model possesses a high resolution in capturing MHD shocks and discontinuities and a low numerical dissipation in examining possible instabilities inherent in the system (4). The model uses a Cartesian coordinate system with the Earth’s center at the origin and X, Y, and Z axes pointing towards the Sun, the dawn-dusk direction, and the north, respectively. The size of the numerical box extends from 25 RE to –100 RE along the Sun-Earth line and from –50 RE to 50 RE in Y and Z directions, with 240×240×240 grid points and a minimum grid spacing of 0.2 RE. An inner boundary of radius 3 RE is set for the magnetosphere to avoid the complexities associated with the plasmasphere and large MHD characteristic velocity from the strong magnetic field (6). An electrostatic ionosphere shell with height-integrated conductance is imbedded, allowing an electrostatic coupling process introduced between the ionosphere and the magnetospheric inner boundary. The Earth’s magnetic field is approximated by a dipole field with a dipole moment of 8.06×1022 A/m in magnitude. The model is run to solve the whole system by inputting the real interplanetary conditions for the current event.论文《夜侧极向弧的形成与演化及其与磁尾瓣高能等离子体的关系》所用三维PPMLR-MHD模型（PPMLR-MHD model）模拟数据 本数据集源自名为PPMLR-MHD模型的三维磁流体力学（MHD）模拟程序的完整运行结果（详细说明见下文）。 本数据集包含两类数据文件： 1. X15dXXXX.mat：存储模拟参数。 2. Xing15XXXX_heatflux.mat：存储模拟得到的热通量数据。 其中XXXX为文件编号，编号相同的文件对应同一模拟时刻。 第一类数据文件包含以下参数： time, x, y, z, logrho, Vx, Vy, Vz, Bx, By, Bz, Pr, Jx, Jy, Jz 各参数含义如下： - time：模拟时刻，需将其与起始时刻16:00相加，即可转换为世界时； - (x, y, z)：模拟点在地心太阳磁层（GSM）坐标系下的位置三分量； - logrho：模拟点处的等离子体密度； - (Vx, Vy, Vz)：地心太阳磁层（GSM）坐标系下模拟点处等离子体速度的三分量； - (Bx, By, Bz)：地心太阳磁层（GSM）坐标系下模拟点处磁场的三分量； - Pr：模拟点处的等离子体动压； - (Jx, Jy, Jz)：地心太阳磁层（GSM）坐标系下模拟点处等离子体电流的三分量。 第二类数据文件包含地心太阳磁层（GSM）坐标系下，模拟点处沿磁力线分布的模拟热通量数据。 PPMLR-MHD模型说明 PPMLR-MHD模型基于分段抛物法（piecewise parabolic method）结合拉格朗日重映的扩展框架，并应用于磁流体力学（MHD）领域[1-3]。该模型为三维磁流体力学模型，专为太阳风-磁层-电离层系统设计[4-6]。其在捕捉磁流体力学激波与间断面时具备高分辨率，且在研究系统固有不稳定性时数值耗散极低[4]。 该模型采用以地球中心为原点的笛卡尔坐标系，X、Y、Z轴分别指向太阳、晨昏方向与正北方向。数值计算盒沿日地连线方向的范围为25地球半径（RE）至-100地球半径（RE），Y、Z方向范围为-50 RE至50 RE，包含240×240×240个网格点，最小网格间距为0.2 RE。为规避等离子体层相关复杂性以及强磁场带来的大磁流体力学特征速度，模型为磁层设置了半径为3 RE的内边界[6]。模型嵌入了具备高度积分电导率的静电电离层壳层，可实现电离层与磁层内边界之间的静电耦合过程。地球磁场近似为偶极场，偶极矩大小为8.06×10^22 A/m。通过输入当前事件的真实行星际条件，模型可求解整个系统的演化过程。