Shaikh Dastgeer, Shukla P K
Center for Space Plasma and Aeronomic Research, The University of Alabama, Huntsville, Alabama 35899, USA.
Phys Rev Lett. 2009 Jan 30;102(4):045004. doi: 10.1103/PhysRevLett.102.045004.
Turbulent spectral cascades are investigated by means of fully three-dimensional (3D) simulations of a compressible Hall-magnetohydrodynamic (H-MHD) plasma in order to understand the observed spectral break in the solar wind turbulence spectra in the regime where the characteristic length scales associated with electromagnetic fluctuations are smaller than the ion gyroradius. In this regime, the results of our 3D simulations exhibit that turbulent spectral cascades in the presence of a mean magnetic field follow an omnidirectional anisotropic inertial-range spectrum close to k(-7/3). The latter is associated with the Hall current arising from nonequal electron and ion fluid velocities in our 3D H-MHD plasma model.
通过对可压缩霍尔磁流体动力学（H-MHD）等离子体进行全三维（3D）模拟来研究湍流谱级联，以便理解在与电磁涨落相关的特征长度尺度小于离子回旋半径的区域中太阳风湍流谱中观测到的谱断点。在该区域，我们的3D模拟结果表明，存在平均磁场时的湍流谱级联遵循接近k^(-7/3)的全向各向异性惯性范围谱。后者与我们的3D H-MHD等离子体模型中电子和离子流体速度不相等所产生的霍尔电流有关。
