论文标题
太阳风湍流中可压缩能级联速率的统计研究：帕克太阳探测器观察
A Statistical Study of the Compressible Energy Cascade Rate in Solar Wind Turbulence: Parker Solar Probe Observations
论文作者
论文摘要
我们研究了在不同的中心距离下太阳风中的不可压缩和可压缩的磁流失动力学（MHD）能量级联速率。我们使用了原位磁场和Parker太阳探针（PSP）任务（PSP）任务以及完全发育的湍流中的精确关系提供的等离子观测。为了估计可压缩的级联速率，我们分别应用了两个最近的精确关系，分别用于可压缩的等温和多面体MHD湍流。我们的观察结果表明，随着我们接近太阳，可压缩和不可压缩的级联速率的绝对值明显增加。此外，随着血浆可压缩性的提高，我们获得了等温和多面级联速率的增加。进一步讨论可压缩性与中心距离之间的关系。此外，我们比较了这两种精确关系，因为太阳风中的可压缩性提高，尽管我们注意到使用多层次闭合观察较大的级联反应的趋势，但我们在观察到的可压缩性范围内获得了基本相同的级联速率。最后，我们研究了签名的不可压缩和可压缩的能量级联速率及其与实际级联速率的联系。
We investigated incompressible and compressible magnetohydrodynamic (MHD) energy cascade rates in the solar wind at different heliocentric distances. We used in situ magnetic field and plasma observations provided by the Parker Solar Probe (PSP) mission and exact relations in fully developed turbulence. To estimate the compressible cascade rate, we applied two recent exact relations for compressible isothermal and polytropic MHD turbulence, respectively. Our observational results show a clear increase of the absolute value of the compressible and incompressible cascade rates as we get closer to the Sun. Moreover, we obtained an increase in both isothermal and polytropic cascade rates with respect to the incompressible case as compressibility increases in the plasma. Further discussion about the relation between the compressibility and the heliocentric distance is carried out. Furthermore, we compared both exact relations as compressibility increases in the solar wind and although we note a slightly trend to observe larger cascades using a polytropic closure, we obtained essentially the same cascade rate in the range of compressibility observed. Finally, we investigated the signed incompressible and compressible energy cascade rates and its connection with the real cascade rate.
