论文标题
Parker太阳探针测量的动力学断裂量表附近太阳风湍流光谱的径向变化
The radial variation of the solar wind turbulence spectra near the kinetic break scale from Parker Solar Probe measurements
论文作者
论文摘要
在这项研究中，我们研究了惯性和耗散范围指标的径向依赖性，以及光谱中断使用{\ it Parker Solar probe}的惯性和耗散范围的功率密度光谱与$ 0.1 $ 0.1 $ 0.1 $ \ sim $ \ sim $ 0.7 au之间的惯性和耗散范围。衍生的断裂波数与较大的径向距离的先前估计值相当合理地比较，并且与热质子通过alfvénic波动的陀螺仪阻尼一致。我们发现惯性尺度功率定律指数在大约-1.65和-1.45之间变化。这与Kolmogorov（-5/3）或Iroshnikov-Kraichnan（-3/2）值一致，具有非常弱的径向依赖性，并可能提示频谱变得更陡峭地靠近太阳。但是，耗散范围的功率定律指数对径向距离（和湍流年龄）具有明显的依赖性，在0.1 au（0.75天）接近太阳的情况下，从0.7 au（4天）接近-3（4天）降低到-4 [$ \ pm 0.3]。
In this study we examine the radial dependence of the inertial and dissipation range indices, as well as the spectral break separating the inertial and dissipation range in power density spectra of interplanetary magnetic field fluctuations using {\it Parker Solar Probe} data from the fifth solar encounter between $\sim$0.1 and $\sim$0.7 au. The derived break wavenumber compares reasonably well with previous estimates at larger radial distances and is consistent with gyro-resonant damping of Alfvénic fluctuations by thermal protons. We find that the inertial scale power law index varies between approximately -1.65 and -1.45. This is consistent with either the Kolmogorov (-5/3) or Iroshnikov-Kraichnan (-3/2) values, has a very weak radial dependence with a possible hint that the spectrum becomes steeper closer to the Sun. The dissipation range power law index, however, has a clear dependence on radial distance (and turbulence age), decreasing from -3 near 0.7 au (4 days) to -4 [$\pm$0.3] at 0.1 au (0.75 days) closer to the Sun.
