PARAMETRIC-INSTABILITIES OF A LARGE-AMPLITUDE CIRCULARLY-POLARIZED ALFVEN-WAVE - LINEAR GROWTH IN 2-DIMENSIONAL GEOMETRIES

被引：41

作者：

GHOSH, S ^{[1
]}

VINAS, AF ^{[1
]}

GOLDSTEIN, ML ^{[1
]}

机构：

[1] NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA

来源：

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS | 1993年 / 98卷 / A9期

关键词：

D O I：

10.1029/93JA01534

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The growth of parametric instabilities, which may lead to the development of a turbulent cascade, is studied using a magnetohydrodynamic (MHD) code that permits nonlinear couplings in the parallel direction to the ambient magnetic field and one perpendicular direction. Compressibility is included in the form of a polytropic equation of state. Parametric instabilities associated with a parallel-propagating decay instability are found to dominate the low-beta case. An obliquely propagating filamentationlike instability dominates the high-beta case. The nonlinear growth of the nth harmonic of a daughter wave growing as a factor of n times the fundamental's growth rate is found in both cases. Nonlinear saturation is caused by the parallel decay instability in the low-beta case and by the oblique filamentationlike instability in the high-beta case.

引用

页码：15561 / 15570

页数：10