日冕冲浪形成的磁流体动力学模拟  

MAGNETOHYDRODYNAMIC SIMULATION ON FORMATION OF CORONAL SURGES

作　　者：郑惠南[1] 苏守军[1] 王水[1] 吴式灿[2] 

机构地区：[1]中国科学技术大学地球和空间科学系,合肥230026 [2]美国阿拉巴马大学

出　　处：《空间科学学报》2000年第1期1-9,共9页Chinese Journal of Space Science

基　　金：国家自然科学基金!49774243;49830026;科技部攀登项目

摘　　要：应用二维时变可压缩磁流体动力学模拟，数值研究了双极一单极磁场中电阻撕裂模不稳定性引起的磁场重联过程，用于模拟日冕冲浪的形成．结果表明，在包含有三区──双极场、电流片和单极场的磁静力平衡初态下，双极场和单极场中的磁力线将会直接重联，磁场演变成鞭状（ｗｈｉｐ）结构．由弯曲磁力线支撑的等离子体团向上运动到最高位置后，逐渐下落和弥散．等离子体团上升速度可达到０．１０ｖＡ（ｖＡ为双极场中的Ａｌｆｖｅｎ速度）．模拟结果证实日冕冲浪的形成可能与双极－单极场中的磁场重联密切相关．In order to simulating the formation of coronal surges, the characteristics ofmagnetic reconnection caused by the resistive tearing instability in bipole-monopolemagnetic field are studied numerically by using a two-dimensional, time-dependent,compressible magnetohydrodynamic simulation. The results show that the magneticlines of the bipole and monopole fields will reconnect directly and the evolution ofmagnetic field leads to a whip configuration under a magnetostatic basic state whichincludes three regions ── a bipole, a current sheet and a monopole. The upwardplasmoid supported by bended magnetic field diffuses and falls back to solar surfaceafter reaching its maximum height. The upward velocity of plasmoid reaches 0.10vA(vA is Alfven velocity in bipole magnetic field). The simulated result confirms thatthe formation of coronal surges may be related closely to magnetic reconnection inbipole-monopole magnetic field.

关 键 词：磁场重联 日冕冲浪 磁流体 动力学模型 

分 类 号：P182.62[天文地球—天文学]