论文标题
内部地球内的各向异性磁湍流 - 帕克太阳能探针观察到的分布的径向演变
Anisotropic Magnetic Turbulence in the Inner Heliosphere -- Radial Evolution of Distributions observed by Parker Solar Probe
论文作者
论文摘要
Parker太阳探针的前五个轨道的观察结果用于研究磁场成分波动的概率密度函数（PDFS）的地震演化，\（\ sim 28 \） - 200 \（\ rs \）之间。将磁场矢量转换为局部平均场坐标系允许相对于平均磁场方向的各向异性检查。注意平均间隔大小的影响。发现垂直波动的pDF被高斯函数很好地近似，平行波动较少：后者的kurtose通常大于10，它们的PDF表明，它们的pdf表明偏置的增加，而距太阳的下降距离\（r \）的距离增加，而后者可能会逐渐被效应。垂直方差的比率大于统一。随着\（r \）的减少，这种方差各向异性变得更强壮。随着\（r \）的降低，总RMS波动强度与平均场幅度的比率降低，在0.14 au处的值\（\ sim 0.8 \）附近的值\（\ sim 0.8 \）附近和\（\ sim 0.5 \）；该比率通过a \（r^{1/4} \）功率定律近似。这些发现提高了我们对太阳风中湍流的径向演变的理解，并对相关现象具有影响，例如内部地球层中的能量粒子转运。
Observations from Parker Solar Probe's first five orbits are used to investigate the helioradial evolution of probability density functions (PDFs) of fluctuations of magnetic field components, between \(\sim 28\) - 200 \(\rs\). Transformation of the magnetic field vector to a local mean-field coordinate system permits examination of anisotropy relative to the mean magnetic field direction. Attention is given to effects of averaging-interval size. It is found that PDFs of the perpendicular fluctuations are well approximated by a Gaussian function, with the parallel fluctuations less so: kurtoses of the latter are generally larger than 10, and their PDFs indicate increasing skewness with decreasing distance \(r\) from the Sun, with the latter observation possibly explained by the increasing Alfvénicity of the fluctuations. The ratio of perpendicular to parallel variances is greater than unity; this variance anisotropy becomes stronger with decreasing \(r\). The ratio of the total rms fluctuation strength to the mean field magnitude decreases with decreasing \(r\), with a value \(\sim 0.8\) near 1 AU and \(\sim 0.5\) at 0.14 AU; the ratio is well approximated by a \(r^{1/4}\) power law. These findings improve our understanding of the radial evolution of turbulence in the solar wind, and have implications for related phenomena such as energetic-particle transport in the inner heliosphere.
