2021/12/03 by Lingling Zhao, L. -L. Zhao, G. P. Zank +3
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Anisotropy #Astro and Planetary Science #Astrophysics #Computational physics #Geomagnetism and Paleomagnetism Studies #Geophysics #Magnetic field #Mechanics #Optics #Physics #Slab #Solar and Space Plasma Dynamics #Solar wind #Spectral density #Turbulence #astro-ph.SR #physics.space-ph
paper · pdf · doi:10.3847/2041-8213/ac4415
This paper is to be published in ApJL
arxiv created 2021/12/03 · openalex publication_date 2022/01/01 · arxiv updated 2022/01/12 · openalex created_date 2022/01/25 · openalex updated_date 2026/08/06
Abstract Solar wind turbulence is anisotropic with respect to the mean magnetic field. Anisotropy leads to ambiguity when interpreting in situ turbulence observations in the solar wind because an apparent change in the measurements could be due to either the change of intrinsic turbulence properties or to a simple change of the spacecraft sampling direction. We demonstrate the ambiguity using the spectral index and magnetic compressibility in the inertial range observed by the Parker Solar Probe during its first seven orbits ranging from 0.1 to 0.6 au. To unravel the effects of the sampling direction, we assess whether the wave-vector anisotropy is consistent with a two-dimensional (2D) plus slab turbulence transport model and determine the fraction of power in the 2D versus slab component. Our results confirm that the 2D plus slab model is consistent with the data and the power ratio between 2D and slab components depends on radial distance, with the relative power in 2D fluctuations becoming smaller closer to the Sun.