Alfvén wave phase mixing driven by velocity shear in two‐dimensional open magnetic configurations
Alfvén wave phase mixing driven by velocity shear in two‐dimensional open magnetic configurations
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DOI：
10.1029/1999ja900144
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发表时间：
1999-08
影响因子：
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通讯作者：
M. Ruderman;M. Goldstein;D. Roberts;A. Deane;L. Ofman
中科院分区：
文献类型：
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作者：
M. Ruderman;M. Goldstein;D. Roberts;A. Deane;L. Ofman
本文研究了具有纯极向磁场和沿场线沿着定常流动的轴对称平衡磁位形中的扭转Alfven波的相位混合。假设沿磁力线的特征波长沿着方向远小于沿磁场方向不均匀性的特征尺度，并采用WKB方法得到描述相位混合的解析解。一般的解决方案被应用到一个特定的配置与径向磁场和流动的假设下，磁场和密度是独立的极角在球坐标系和流速是独立的径向坐标。在这种配置中，相混合的唯一来源是速度剪切。将解析解与完全非线性电阻MHD方程的数值模拟进行了比较。数值结果与解析结果吻合良好。波能沉积到太阳日冕和太阳风的阿尔芬波能谱的演变的后果进行了讨论。
Phase mixing of torsional Alfven waves in axisymmetric equilibrium magnetic configurations with purely poloidal magnetic field and stationary flow along the field lines in resistive viscous plasmas is studied. The characteristic wavelength along the magnetic field lines is assumed to be much smaller than the characteristic scale of inhomogeneity in the magnetic field direction, and the WKB method is used to obtain an analytic solution describing phase mixing. The general solution is applied to a particular configuration with the radial magnetic field and flow under the assumptions that the magnetic field and density are independent of the polar angle in the spherical coordinates and the flow velocity is independent of the radial coordinate. The only source of phase mixing in this configuration is velocity shear. The analytical solution is compared with a numerical simulation of the fully nonlinear resistive MHD equations. The numerical and analytical results are in good agreement. Consequences for wave energy deposition into the solar corona and solar wind and for the evolution of the Alfven wave energy spectrum are discussed.