“Aging” of the magnetotail thin current sheets
“Aging” of the magnetotail thin current sheets
复制标题
磁尾薄电流片的“老化”
DOI：
10.1029/2001gl013789
复制
发表时间：
2002
影响因子：
5.2
通讯作者：
A. S. Sharma
中科院分区：
文献类型：
--
作者：
Lev Zelenyi;D. Delcourt;H. Malova;A. S. Sharma
本文对存在非绝热效应的薄电流片(TCS)的形成进行了自洽分析。结果表明，粒子运动的非绝热性对粒子具有Speiser轨道的“年轻”电流片的结构有显著影响。这导致了具有大磁矩的离子的出现，从而减少了薄片中心的电流。由于粒子运动的绝热不变量不可避免地发生非绝热跳跃，TCS随之恶化，从而导致其“老化”。当产生的准囚禁域变得高度填充时，电流就会衰减。由于系统的混沌特性，TCS的特征寿命约为10-60分钟。这一效应提供了一种新的进化机制，最终导致CS结构的破坏，至少在我们的一维模型框架内是这样。
Paper is devoted to the self‐consistent analysis of thin current sheets (TCSs) formation in the presence of nonadiabatic effects. It is shown that nonadiabaticity of particle motion influences significantly the structure of “young” current sheets in which the particles have Speiser orbits. This results into the appearance of ions with large magnetic moments which reduces the current in the center of the sheet. The TCS then deteriorates, which leads to its “aging” due to the unavoidable nonadiabatic jumps of the adiabatic invariants of particle motion. When the resulting quasi‐trapped domain becomes highly populated, the current decays. The characteristic lifetime of TCS due to the chaotic nature of the system is found to be about 10–60 minutes. This effect provides a new evolutionary mechanism which finally leads to the disruption of CS structure, at least in the frames of our 1D model.