Magnetohydrodynamic Simulation of Solar Coronal Chromospheric Evaporation Jets Caused by Magnetic Reconnection Associated with Magnetic Flux Emergence
Magnetohydrodynamic Simulation of Solar Coronal Chromospheric Evaporation Jets Caused by Magnetic Reconnection Associated with Magnetic Flux Emergence
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DOI：
10.1086/423731
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发表时间：
2004-10
期刊：
影响因子：
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通讯作者：
T. Miyagoshi;T. Yokoyama
中科院分区：
文献类型：
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作者：
T. Miyagoshi;T. Yokoyama
基于磁重联模型，对日冕X射线喷流进行了具有热传导效应的MHD数值模拟。其中包括关键的物理过程，如来自对流区的磁通量的出现，与日冕磁场的磁重联，向色球的热传导，以及色球的蒸发。然而，辐射一直被忽视。在模拟中成功地再现了高密度蒸发射流。描述了蒸发喷流的质量M=6.8×1012G(B/10G)15/7(TcoR/106K)5/14(L/5000公里)12/7(t/400 S)，其中B是磁场强度，Tcor是日冕温度，L是环高度，t是抛射持续时间。我们还推导了重联喷流马赫数作为环境日冕变量的函数的理论模型。数值模拟还表明，在浮现通量区附近同时存在两种不同类型的射流(蒸发射流和低密度射流)，蒸发射流的能量比低密度射流的能量稍大。
We studied solar coronal X-ray jets by MHD numerical simulations with heat conduction effects based on a magnetic reconnection model. Key physical processes are included, such as the emergence of magnetic flux from the convection zone, magnetic reconnection with the coronal magnetic fields, heat conduction to the chromosphere, and chromospheric evaporation. Radiation, however, has been neglected. High-density evaporation jets were successfully reproduced in the simulations. The mass of the evaporation jets M is described as M = 6.8 × 1012g(B/10 G)15/7(Tcor/106 K)5/14(L/5000 km)12/7(t/400 s), where B is the strength of magnetic fields, Tcor is the coronal temperature, L is the loop height, and t is the duration of ejection, respectively. We also derived a theoretical model of the Mach number of the reconnection jets as a function of ambient coronal variables. Numerical simulations also show that two different types of jets (evaporation jets and low-density jets) exist simultaneously around the emerging flux region, and the energy of evaporation jets is somewhat larger than that of the low-density jets.