电流片的形成

采用二维三分量的耗散磁流体力学模型,对由于光球层的剪切运动引起的四极磁场内电流片的形成过程进行数值模拟。结果表明,磁分隔线在磁场的演化过程中起关键作用。电流主要在分隔面和根部剪切梯度较大的磁环中形成,其中在分隔线上最强。磁分隔线可以被拉长,形成强电流片,随着速度剪切位置的不同,电流片的形成模式也不同,既可以形成与光球层垂直的电流片,也可以形成平行的电流片。 

FORMATION OF CURRENT SHEETS

Using two dimensional three component dissipative MHD model,a numerical simulation is presented concerning the current formation process in a quadrupolar potentiel magnetic field caused by photospheric shear motion. Separator plays a key role in the evolution Of the magnetic field f Current mainly builds up in separatrices and the magnetic loops in which the foot shear gradient is muximum.In separator;the current density reaches its maximum value.The photospheric shear inchon may lead to Separator splitting into strong current sheet,parallel or vertical to photosphere, depending on the location and gradient of the shear.