TitleIdentification of Magnetic Flux Ropes from Parker Solar Probe Observations during the First Encounter
Publication TypeJournal Article
Year of Publication2020
AuthorsZhao, L-L, Zank, GP, Adhikari, L, Hu, Q, Kasper, JC, Bale, SD, Korreck, KE, Case, AW, Stevens, M, Bonnell, JW, T. de Wit, D, Goetz, K, Harvey, PR, MacDowall, RJ, Malaspina, DM, Pulupa, M, Larson, DE, Livi, R, Whittlesey, P, Klein, KG
JournalThe Astrophysical Journal Supplement Series
Volume246
Issue2
Pagination26
Date Published02/2020
KeywordsAstrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics - Space Physics; Solar Probe Plus
Abstract

The Parker Solar Probe (PSP) observed an interplanetary coronal mass ejection (ICME) event during its first orbit around the Sun, among many other events. This event is analyzed by applying a wavelet analysis technique to obtain the reduced magnetic helicity, cross helicity, and residual energy, the first two of which are magnetohydrodynamics (MHD) invariants. Our results show that the ICME, as a large-scale magnetic flux rope, possesses high magnetic helicity, very low cross helicity, and highly negative residual energy, thus pointing to a magnetic fluctuation dominated structure. Using the same technique, we also search for small-scale coherent magnetic flux rope structures during the period from 2018 October 22 to November 21, which are intrinsic to quasi-two-dimensional MHD turbulence in the solar wind. Multiple structures with durations between 8 and 300 minutes are identified from PSP in situ spacecraft measurements. The location and scales of these structures are characterized by wavelet spectrograms of the normalized reduced magnetic helicity, normalized cross helicity, and normalized residual energy. Transport theory suggests that these small-scale magnetic flux ropes may contribute to the acceleration of charged particles through magnetic reconnection processes, and the dissipation of these structures may be important for understanding the coronal heating processes.

URLhttps://iopscience.iop.org/article/10.3847/1538-4365/ab4ff1
DOI10.3847/1538-4365/ab4ff1
Short TitleApJS


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