2004年4月1日磁通量传输事件特性的研究——通量管内电流密度、粒子运动与管轴方向的对比分析

CHARACTERISTICS OF THE MAGNETIC FLUX TRANSFER EVENTS ON APRIL 1 OF 2004

本文利用Cluster四颗卫星上磁通门磁力计(FGM)的同时观测,采用旋度器方法(Curlometer),计算和分析了2004年4月1日12:24到12:54UT期间Cluster卫星观测的多个磁通量传输事件(FTEs)的特性。结果表明:磁通量管内电流密度较大,可达到约10-7A/m2。应用最小方向微分法(MDD),发现这些FTE事件具有准二维结构,即为圆柱形结构,其通量管轴线方向与管内电流方向及粒子运动方向基本平行。

Based on the simultaneous FGM observations of 4 Cluster satellites, this paper calculated and analyzed the current density of FTEs occurred between 12 ： 24 and 12 ： 54UT on April 1, 2004 by using the Curlometer analyzer. It showed that intense current flows inside the flux tubes with the current density reaching as high as about 10^-7A/m^2. By Minimum Directional Derivative （or Difference） （MDD） analyzing, it was also found that the FTEs were of the quasi-2D structure, the direction of the current was almost parallel to the plasma flows and the axis of the flux tubes.