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Found 11 entries in the Bibliography.
Showing entries from 1 through 11
Magnetic Reconnection as the Driver of the Solar Wind
We present EUV solar observations showing evidence for omnipresent jetting activity driven by small-scale magnetic reconnection at the base of the solar corona. We argue that the physical mechanism that heats and drives the solar wind at its source is ubiquitous magnetic reconnection in the form of small-scale jetting activity (a.k.a. jetlets). This jetting activity, like the solar wind and the heating of the coronal plasma, is ubiquitous regardless of the solar cycle phase. Each event arises from small-scale reconnection of ...
Raouafi, Nour; Stenborg, G.; Seaton, D.~B.; Wang, H.; Wang, J.; DeForest, C.~E.; Bale, S.~D.; Drake, J.~F.; Uritsky, V.~M.; Karpen, J.~T.; DeVore, C.~R.; Sterling, A.~C.; Horbury, T.~S.; Harra, L.~K.; Bourouaine, S.; Kasper, J.~C.; Kumar, P.; Phan, T.~D.; Velli, M.;
Published by: \apj Published on: mar
YEAR: 2023   DOI: 10.3847/1538-4357/acaf6c
Parker Data Used; Solar corona; Solar wind; magnetic fields; Solar magnetic reconnection; 1483; 1534; 994; 1504; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics
Parker Solar Probe: Four Years of Discoveries at Solar Cycle Minimum
Launched on 12 Aug. 2018, NASA s Parker Solar Probe had completed 13 of its scheduled 24 orbits around the Sun by Nov. 2022. The mission s primary science goal is to determine the structure and dynamics of the Sun s coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what processes accelerate energetic particles. Parker Solar Probe returned a treasure trove of science data that far exceeded quality, significance, and quantity expectations, leading to a significant number ...
Raouafi, N.~E.; Matteini, L.; Squire, J.; Badman, S.~T.; Velli, M.; Klein, K.~G.; Chen, C.~H.~K.; Matthaeus, W.~H.; Szabo, A.; Linton, M.; Allen, R.~C.; Szalay, J.~R.; Bruno, R.; Decker, R.~B.; Akhavan-Tafti, M.; Agapitov, O.~V.; Bale, S.~D.; Bandyopadhyay, R.; Battams, K.; Ber\vci\vc, L.; Bourouaine, S.; Bowen, T.~A.; Cattell, C.; Chandran, B.~D.~G.; Chhiber, R.; Cohen, C.~M.~S.; Amicis, R.; Giacalone, J.; Hess, P.; Howard, R.~A.; Horbury, T.~S.; Jagarlamudi, V.~K.; Joyce, C.~J.; Kasper, J.~C.; Kinnison, J.; Laker, R.; Liewer, P.; Malaspina, D.~M.; Mann, I.; McComas, D.~J.; Niembro-Hernandez, T.; Nieves-Chinchilla, T.; Panasenco, O.; y, Pokorn\; Pusack, A.; Pulupa, M.; Perez, J.~C.; Riley, P.; Rouillard, A.~P.; Shi, C.; Stenborg, G.; Tenerani, A.; Verniero, J.~L.; Viall, N.; Vourlidas, A.; Wood, B.~E.; Woodham, L.~D.; Woolley, T.;
Published by: ßr Published on: feb
YEAR: 2023   DOI: 10.1007/s11214-023-00952-4
Parker Data Used; Sun; Corona; Solar wind; plasma; magnetic fields; coronal mass ejections; parker solar probe; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics
Features of Magnetic Field Switchbacks in Relation to the Local-field Geometry of Large-amplitude Alfv\ enic Oscillations: Wind and PSP Observations
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 $. In the solar-wind streams that we analyzed, these specific SB features near 1 au are associated with large-amplitude Alf ...
Bourouaine, Sofiane; Perez, Jean; Raouafi, Nour; Chandran, Benjamin; Bale, Stuart; Velli, Marco;
Published by: \apjl Published on: jun
YEAR: 2022   DOI: 10.3847/2041-8213/ac67d9
Parker Data Used; Heliosphere; Solar wind; 711; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics
The near-Sun streamer belt solar wind: turbulence and solar wind acceleration
The fourth orbit of Parker Solar Probe (PSP) reached heliocentric distances down to 27.9 R$_\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"
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
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
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
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
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
On the Limitations of Taylor s Hypothesis in Parker Solar Probe s Measurements near the Alfven Critical Point
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
Stochastic Heating, Differential Flow, and the Alpha-to-proton Temperature Ratio in the Solar Wind
Chandran, B.~D.~G.; Verscharen, D.; Quataert, E.; Kasper, J.~C.; Isenberg, P.~A.; Bourouaine, S.;
Published by: \apj Published on: 10/2013
YEAR: 2013   DOI: 10.1088/0004-637X/776/1/45
Parker Data Used; plasmas; Solar wind; Sun: corona; turbulence; waves; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics