太阳风中Alfven湍流的起源  

THE GENERATION OF THE ALFVENIC TURBULENCE IN THE SOLAR WIND

作　　者：宋礼庭[1] 谢伦[1] 

机构地区：[1]北京大学地球物理学系

出　　处：《地球物理学报》2003年第4期433-437,共5页Chinese Journal of Geophysics

基　　金：国家自然科学基金重大项目 ( 4 9990 45 2 ) .

摘　　要：由动力Alfven波沿磁场方向传播的扰动非线性方程 ,用量纲分析法导出太阳风中Alfven湍流谱 .太阳风中观测到的湍流谱恰是由方程得到谱的特例 .我们提出太阳风中Alfven湍流是一支反向串级的湍流 ,正向串级的一支湍流已经用于日冕而耗散掉 .理论上提出这支反向的Alfven湍流产生机制是由于动力Alfven波的非线性色散造成的调制不稳定性驱动的 .The power spectrum of the kinetic Alfven turbulence is obtained from the nonlinear equations of the kinetic Alfven wave propagating along the magnetic field using dimensional analysis. The observed power spectrum of the solar wind turbulence is the special case of the calculated spectra from the nonlinear equations. It is suggested that:1)the observed Alfvenic turbulence in the solar wind is evaluated from a inverse-cascade turbulence, while the other cascade one has been damped for corona heating; 2)The inverse-cascade Alfvenic turbulence is driven by the modulation instability of the nonlinear dispersion of the kinetic Alfven wave.

关 键 词：太阳风 Alfven湍流 起源 湍流谱 反向串级 调制不稳定性 非线性色散 ALFVEN波 

分 类 号：P425.2[天文地球—大气科学及气象学]