论文标题
在太阳能街机中的磁性零点的两流体射流的数值模拟
Numerical simulations of a two-fluid jet at a magnetic null point in a solar arcade
论文作者
论文摘要
我们使用部分电离等离子体的数值模拟研究了太阳大气中喷气机的形成和演变。带有离子+电子和中性氢成分的两流体磁水动力学方程用于二维（2D）笛卡尔几何形状。数值模拟表明，最初从位于过渡区域下方的电势弧形的磁性null点发射的局部非线性高斯脉冲和中性压力，由于密度随着高度的降低而迅速发展为冲击。冲击使太阳电晕传播到太阳电晕，并以具有倒y形状的准射流的形式抬起冷和密集的色球等离子体。喷气机的反向形状与磁性空点的拓扑相关。该脉冲还激发了染色体中的非线性唤醒，从而导致准周期性次要冲击。次要冲击使色球等离子体向上提升，并在下部电晕中产生准周期性喷气机。离子和中性流体通常显示出相似的行为，但它们的相对速度在喷气机上部附近较高，这会导致因离子中性碰撞而引起的温度或加热。用反向形状及其加热的喷气机的模拟可以解释在太阳大气中观察到的某些喷气机的特性。
We study the formation and evolution of jets in the solar atmosphere using numerical simulations of partially ionized plasma. The two-fluid magnetohydrodynamic equations with ion+electron and neutral hydrogen components are used in two-dimensional (2D) Cartesian geometry. Numerical simulations show that a localized nonlinear Gaussian pulse of ion and neutral pressures initially launched from the magnetic null point of a potential arcade located below the transition region quickly develops into a shock due to the decrease of density with height. The shock propagates upwards into the solar corona and lifts the cold and dense chromospheric plasma behind in the form of a collimated jet with an inverted-Y shape. The inverted-Y shape of jets is connected with the topology of a magnetic null point. The pulse also excites a nonlinear wake in the chromosphere, which leads to quasi-periodic secondary shocks. The secondary shocks lift the chromospheric plasma upwards and create quasi-periodic jets in the lower corona. Ion and neutral fluids show generally similar behavior, but their relative velocity is higher near the upper part of jets, which leads to enhanced temperature or heating due to ion-neutral collisions. Simulations of jets with inverted-Y shape and their heating may explain the properties of some jets observed in the solar atmosphere.
