Configuration of the magnetosphere-ionosphere convection system under northward IMF conditions with nonzero IMF
Configuration of the magnetosphere-ionosphere convection system under northward IMF conditions with nonzero IMF
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DOI：
10.1029/1999ja900077
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发表时间：
1999-07
影响因子：
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通讯作者：
T. Tanaka
中科院分区：
文献类型：
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作者：
T. Tanaka
通过分析太阳风-磁层-电离层（S-M-I）耦合过程的全球磁流体动力学（MHD）模型输出，研究了磁层-电离层对流系统的结构。模型的输入行星际磁场（IMF）与正北方向成45°角，IMF向下。结果清楚地表明，在极区电离层中形成了圆胞和新月胞，磁层中的叶胞和合并胞分别与圆胞的核心和外圆胞及新月胞相连。构成叶细胞环流的开磁力线是通过尖点向极侧的开磁力线重联以及未连接的磁力线产生的。从北方（南）半球的外圆环流圈延伸出来的构成合并单体对流的开放磁力线是通过北方（南）半球的闭合磁力线重联产生的，而从北方（南）半球的新月形环流圈延伸出来的开放磁力线是在南（北方）半球产生的。通过叶对流，从北方外圆细胞的开放场线重新连接到从扭曲的等离子体片的东北边缘的南部新月形细胞的开放场线。在等离子体片中，合并单体对流的特征会变得非常复杂。
The configuration of the magnetosphere-ionosphere convection system is investigated by analyzing outputs of a global magnetohydrodynamic (MHD) model for the solar wind-magnetosphere-ionosphere (S-M-I) coupling process. The input interplanetary magnetic field (IMF) to the model is inclined 45° from the due-northward direction with downward IMF. The results clearly show that the round cell and crescent cell are formed in the polar ionosphere and that the lobe cell and merging cell in the magnetosphere are connected to the core of the round cell and to the outer round and crescent cells, respectively. The open field lines that construct the lobe-cell circulation are generated through the open-field-line reconnection on the poleward side of the cusp, together with unconnected field lines. The open magnetic field lines that extend from the outer round cell in the Northern (Southern) Hemisphere and construct the merging-cell convection are generated through the closed-field-line reconnection in the Northern (Southern) Hemisphere, while the open magnetic field lines that extend from the crescent cell in the Northern (Southern) Hemisphere are generated in the Southern (Northern) Hemisphere. Convecting through the lobe, the open field lines from the northern outer round cell reconnect with the open field lines from the southern crescent cell in the northeast edge of the twisted plasma sheet. The features of the merging-cell convection can become very complicated in the plasma sheet.