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Intermittency in the Expanding Solar Wind: Observations from Parker Solar Probe (0.16 au), Helios 1 (0.3-1 au), and Voyager 1 (1-10 au)
Author | Cuesta, Manuel; Parashar, Tulasi; Chhiber, Rohit; Matthaeus, William; |
Keywords | Parker Data Used; Solar wind; interplanetary magnetic fields; Space plasmas; interplanetary turbulence; Interplanetary physics; 1534; 824; 1544; 830; 827; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
Abstract | We examine statistics of magnetic-field vector components to explore how intermittency evolves from near-Sun plasma to radial distances as large as 10 au. Statistics entering the analysis include autocorrelation, magnetic structure functions of the order of n (SF$_ n $), and scale-dependent kurtosis (SDK), each grouped in ranges of heliocentric distance. The Goddard Space Flight Center Space Physics Data Facility provides magnetic-field measurements for resolutions of 6.8 ms for Parker Solar Probe, 6 s for Helios, and 1.92 s for Voyager 1. We compute SF$_2$ to determine the scales encompassing the inertial range and examine SDK to investigate the degree of non-Gaussianity. Autocorrelations are used to resolve correlation scales. Correlation lengths and ion inertial lengths provide an estimate of effective Reynolds number (R$_e$). Variation in R$_e$ allows us to examine for the first time the relationship between SDK and R$_e$ in an interplanetary plasma. A conclusion from this observed relationship is that regions with lower R$_e$ at a fixed physical scale have on average lower kurtosis, implying less intermittent behavior. Kolmogorov refined similarity hypothesis is applied to magnetic SF$_ n $ and kurtosis to calculate intermittency parameters and fractal scaling in the inertial range. A refined Voyager 1 magnetic-field data set is generated. |
Year of Publication | 2022 |
Journal | \apjs |
Volume | 259 |
Number of Pages | 23 |
Section | |
Date Published | mar |
ISBN | |
URL | |
DOI | 10.3847/1538-4365/ac45fa |