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Found 12 entries in the Bibliography.
Showing entries from 1 through 12
| 2022 |
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In this Letter, we report observations of magnetic switchback (SB) features near 1 au using data from the Wind spacecraft. These features appear to be strikingly similar to the ones observed by the Parker Solar Probe mission closer to the Sun: namely, one- sided spikes (or enhancements) in the solar-wind bulk speed V that correlate/anticorrelate with the spikes seen in the radial- field component B $_ R $. In the solar-wind streams that we analyzed, these specific SB features near 1 au are associated with large-amplitude Alf ... Bourouaine, Sofiane; Perez, Jean; Raouafi, Nour; Chandran, Benjamin; Bale, Stuart; Velli, Marco; Published by: \apjl Published on: jun YEAR: 2022 DOI: 10.3847/2041-8213/ac67d9 Parker Data Used; Heliosphere; Solar wind; 711; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
| 2021 |
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The near-Sun streamer belt solar wind: turbulence and solar wind acceleration The fourth orbit of Parker Solar Probe (PSP) reached heliocentric distances down to 27.9 R$_\ensuremath\odot$, allowing solar wind turbulence and acceleration mechanisms to be studied in situ closer to the Sun than previously possible. The turbulence properties were found to be significantly different in the inbound and outbound portions of PSP s fourth solar encounter, which was likely due to the proximity to the heliospheric current sheet (HCS) in the outbound period. Near the HCS, in the streamer belt wind, the turbulence ... Chen, C.; Chandran, B.; Woodham, L.; Jones, S.; Perez, J.; Bourouaine, S.; Bowen, T.; Klein, K.; Moncuquet, M.; Kasper, J.; Bale, S.; Published by: Astronomy and Astrophysics Published on: jun YEAR: 2021 DOI: "10.1051/0004-6361/202039872" |
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Applicability of Taylor s hypothesis during Parker Solar Probe perihelia We investigate the validity of Taylor s hypothesis (TH) in the analysis of velocity and magnetic field fluctuations in Alfvénic solar wind streams measured by Parker Solar Probe (PSP) during the first four encounters. The analysis is based on a recent model of the spacetime correlation of magnetohydrodynamic (MHD) turbulence, which has been validated in high-resolution numerical simulations of strong reduced MHD turbulence. We use PSP velocity and magnetic field measurements from 24 h intervals selected from each of the fir ... Perez, Jean; Bourouaine, Sofiane; Chen, Christopher; Raouafi, Nour; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039879 Solar wind; Sun: heliosphere; turbulence; magnetohydrodynamics (MHD); plasmas; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
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How Alfvén waves energize the solar wind: heat versus work A growing body of evidence suggests that the solar wind is powered to a large extent by an Alfvén-wave (AW) energy flux. AWs energize the solar wind via two mechanisms: heating and work. We use high-resolution direct numerical simulations of reflection-driven AW turbulence (RDAWT) in a fast-solar-wind stream emanating from a coronal hole to investigate both mechanisms. In particular, we compute the fraction of the AW power at the coronal base ($P_\textrm AWb$) that is transferred to solar-wind particles via heating between ... Perez, Jean; Chandran, Benjamin; Klein, Kristopher; Martinovic, Mihailo; Published by: Journal of Plasma Physics Published on: 04/2021 YEAR: 2021 DOI: 10.1017/S0022377821000167 Parker Data Used; astrophysical plasmas; space plasma physics; plasma nonlinear phenomena; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
| 2020 |
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Turbulence Characteristics of Switchback and Nonswitchback Intervals Observed by Parker Solar Probe We use Parker Solar Probe (PSP) in situ measurements to analyze the characteristics of solar wind turbulence during the first solar encounter covering radial distances between 35.7R and 41.7R. In our analysis we isolate so-called switchback (SB) intervals (folded magnetic field lines) from nonswitchback (NSB) intervals, which mainly follow the Parker spiral field. Using a technique based on conditioned correlation functions, we estimate the power spectra of Elsasser, magnetic, and bulk velocity fields separately in the SB an ... Bourouaine, Sofiane; Perez, Jean; Klein, Kristopher; Chen, Christopher; Martinovic, Mihailo; Bale, Stuart; Kasper, Justin; Raouafi, Nour; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: 12/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abbd4a |
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Eulerian space-time correlation of strong magnetohydrodynamic turbulence Perez, Jean; Bourouaine, Sofiane; Published by: Physical Review Research Published on: 06/2020 YEAR: 2020 DOI: 10.1103/PhysRevResearch.2.023357 Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Two-time energy spectrum of weak magnetohydrodynamic turbulence In this work a weak-turbulence closure is used to determine the structure of the two-time power spectrum of weak magnetohydrodynamic (MHD) turbulence from the nonlinear equations describing the dynamics. The two-time energy spectrum is a fundamental quantity in turbulence theory from which most statistical properties of a homogeneous turbulent system can be derived. A closely related quantity, obtained via a spatial Fourier transform, is the two-point two-time correlation function describing the space-time correlations arisi ... Perez, Jean; Azelis, Augustus; Bourouaine, Sofiane; Published by: PHYSICAL REVIEW RESEARCH Published on: 05/2020 YEAR: 2020 DOI: 10.1103/PhysRevResearch.2.023189 |
| 2019 |
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Reflection-driven magnetohydrodynamic turbulence in the solar atmosphere and solar wind Chandran, Benjamin; Perez, Jean; Published by: Journal of Plasma Physics Published on: 08/2019 YEAR: 2019 DOI: 10.1017/S0022377819000540 Parker Data Used; astrophysical plasmas; plasma nonlinear phenomena; space plasma physics; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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On the Interpretation of Parker Solar Probe Turbulent Signals In this Letter we propose a practical methodology to interpret future Parker Solar Probe (PSP) turbulent time signals even when Taylor s hypothesis is not valid. By extending Kraichnan s sweeping model used in hydrodynamics we derive the Eulerian spacetime correlation function in magnetohydrodynamic (MHD) turbulence. It is shown that in MHD, the temporal decorrelation of small-scale fluctuations arises from a combination of hydrodynamic sweeping induced by large-scale fluid velocity delta u(0) and by the Alfvenic propagation ... Bourouaine, Sofiane; Perez, Jean; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: 07/2019 YEAR: 2019 DOI: 10.3847/2041-8213/ab288a |
| 2018 |
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In this Letter, we present an analysis of two-point, two-time correlation functions from high-resolution numerical simulations of Reflection-driven Alfven Turbulence near the Alfven critical point r e . The simulations model the turbulence in a prescribed background solar wind model chosen to match observational constraints. This analysis allows us to investigate the temporal decorrelation of solar wind turbulence and the validity of Taylor s approximation near the heliocentric distance r(c), which Parker Solar Probe (PSP) i ... Bourouaine, Sofiane; Perez, Jean; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: 05/2018 YEAR: 2018 DOI: 10.3847/2041-8213/aabccf |
| 2015 |
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A MODIFIED VERSION OF TAYLOR\textquoterightS HYPOTHESIS FOR SOLAR PROBE PLUS OBSERVATIONS The Solar Probe Plus (SPP) spacecraft will explore the near-Sun environment, reaching heliocentric distances less than 10 R☉ . Near Earth, spacecraft measurements of fluctuating velocities and magnetic fields taken in the time domain are translated into information about the spatial structure of the solar wind via Taylor\textquoterights \textquotedblleftfrozen turbulence\textquotedblright hypothesis. Near the perihelion of SPP, however, the solar-wind speed is comparable to the Alfv\ en speed, and Taylor\text ... Klein, Kristopher; Perez, Jean; Verscharen, Daniel; Mallet, Alfred; Chandran, Benjamin; Published by: The Astrophysical Journal Published on: 03/2015 YEAR: 2015 DOI: 10.1088/2041-8205/801/1/L18 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; Sun: corona; turbulence |
| 2013 |
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Perez, Jean; Chandran, Benjamin; Published by: \apj Published on: 10/2013 YEAR: 2013 DOI: 10.1088/0004-637X/776/2/124 Parker Data Used; magnetohydrodynamics: MHD; Solar wind; Sun: corona; turbulence; waves |
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