Sioulas, Nikos;
Huang, Zesen;
Velli, Marco;
Chhiber, Rohit;
Cuesta, Manuel E;
Shi, Chen;
Matthaeus, William H;
... Livi, Roberto; + view all
(2022)
Magnetic Field Intermittency in the Solar Wind: Parker Solar Probe and SolO Observations Ranging from the Alfven Region up to 1 AU.
The Astrophysical Journal
, 934
(2)
, Article 143. 10.3847/1538-4357/ac7aa2.
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Abstract
Parker Solar Probe (PSP) and SolO data are utilized to investigate magnetic field intermittency in the solar wind (SW). Small-scale intermittency (20−100 di) is observed to radially strengthen when methods relying on higher-order moments are considered (SFq; SDK), but no clear trend is observed at larger scales. However, lower-order moment-based methods (e.g., partial variance of increments; PVI) are deemed more appropriate for examining the evolution of the bulk of coherent structures (CSs), PVI ≥ 3. Using PVI, we observe a scale-dependent evolution in the fraction of the data set occupied by CSs, fPVI≥3. Specifically, regardless of the SW speed, a subtle increase is found in fPVI≥3 for ℓ = 20 di, in contrast to a more pronounced radial increase in CSs observed at larger scales. Intermittency is investigated in relation to plasma parameters. Though, slower SW speed intervals exhibit higher fPVI≥6 and higher kurtosis maxima, no statistical differences are observed for fPVI≥3. Highly Alfvénic intervals display lower levels of intermittency. The anisotropy with respect to the angle between the magnetic field and SW flow, ΘVB is investigated. Intermittency is weaker at ΘVB ≈ 0° and is strengthened at larger angles. Considering the evolution at a constant alignment angle, a weakening of intermittency is observed with increasing advection time of the SW. Our results indicate that the strengthening of intermittency in the inner heliosphere is driven by the increase in comparatively highly intermittent perpendicular intervals sampled by the probes with increasing distance, an effect related directly to the evolution of the Parker spiral.
Type: | Article |
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Title: | Magnetic Field Intermittency in the Solar Wind: Parker Solar Probe and SolO Observations Ranging from the Alfven Region up to 1 AU |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.3847/1538-4357/ac7aa2 |
Publisher version: | https://doi.org/10.3847/1538-4357/ac7aa2 |
Language: | English |
Additional information: | © 2022 IOP Publishing. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Solar wind (1534); Interplanetary turbulence (830); Magnetohydrodynamics (1964); Space plasmas (1544); Plasma astrophysics (1261); Solar physics (1476) |
UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10154496 |
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