Wave-driven Turbulent Coronal Heating in Open Field Line Regions: Nonlinear Phenomenological Model
Wave-driven Turbulent Coronal Heating in Open Field Line Regions: Nonlinear Phenomenological Model
复制标题
开放场线区域中波驱动的湍流日冕加热：非线性唯象模型
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
W. Matthaeus
中科院分区：
文献类型：
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作者：
P. Dmitruk;L. Milano;W. Matthaeus
提出了一个模型来研究日冕湍流的驱动力在开放的磁力线区域，在日冕底部的低频振荡磁力线运动供电。该模型结合了波的传播，反射与梯度的Alfvén速度，和低频准二维湍流，这是治疗使用一个点关闭现象适合于一个横向级联在减少磁流体动力学制度的综合效果。考虑样本的日冕和采用开放的边界条件，我们使用该模型来研究湍流耗散的动力学效率，这与传播的波动远离日冕基地的竞争。我们研究的依赖性的加热效率的波强迫频率，控制阿尔文速度分布的参数的敏感性，模型的行为变化的湍流的现象学相关长度，包括渐近极限的可忽略不计或非常强烈的非线性，和限制的湍流耗散的区域附近的日冕底部。这些问题中的每一个都可能对理解日冕的加热和太阳风的起源很重要。
A model is presented to investigate the driving of coronal turbulence in open field line regions, powered by low-frequency oscillatory field line motions at the coronal base. The model incorporates the combined effects of wave propagation, reflection associated with gradients of Alfvén speed, and low-frequency quasi-two-dimensional turbulence, which is treated using a one-point closure phenomenology appropriate to a transverse cascade in the reduced magnetohydrodynamic regime. Considering a sample of the corona and employing open boundary conditions, we use the model to investigate the dynamical efficiency of turbulent dissipation, which competes with propagation of fluctuations away from the coronal base. We examine the dependence of the heating efficiency on wave-forcing frequency, the sensitivity to parameters controlling the Alfvén speed profile, the behavior of the model for varying the phenomenological correlation length of turbulence, including asymptotic limits of negligible or very intense nonlinearities, and the confinement of turbulent dissipation to the region near the coronal base. Each of these issues may be of importance in understanding the heating of the corona and the origin of the solar wind.