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Found 96 entries in the Bibliography.
Showing entries from 1 through 50
| 2021 |
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Parker solar probe observations of helical structures as boundaries for energetic particles Energetic particle transport in the interplanetary medium is known to be affected by magnetic structures. It has been demonstrated for solar energetic particles in near-Earth orbit studies, and also for the more energetic cosmic rays. In this paper, we show observational evidence that intensity variations of solar energetic particles can be correlated with the occurrence of helical magnetic flux tubes and their boundaries. The analysis is carried out using data from Parker Solar Probe orbit 5, in the period 2020 May 24 to Ju ... Pecora, F.; Servidio, S.; Greco, A.; Matthaeus, W.~H.; McComas, D.~J.; Giacalone, J.; Joyce, C.~J.; Getachew, T.; Cohen, C.~M.~S.; Leske, R.~A.; Wiedenbeck, M.~E.; McNutt, R.~L.; Hill, M.~E.; Mitchell, D.~G.; Christian, E.~R.; Roelof, E.~C.; Schwadron, N.~A.; Bale, S.~D.; Published by: \mnras Published on: sep YEAR: 2021 DOI: 10.1093/mnras/stab2659 magnetic fields; plasmas; Sun: magnetic fields; Sun: solar wind; Sun: particle emission; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
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Triggered Ion-acoustic Waves in the Solar Wind For more than 12 hr beginning on 2021 January 18, continuous narrowband electrostatic emissions were observed on the Parker Solar Probe near 20 solar radii. The observed <1000 Hz frequencies were well below the local ion-plasma frequency. Surprisingly, the emissions consisted of electrostatic wave packets with shock- like envelopes, appearing repetitively at a \raisebox-0.5ex\textasciitilde1.5 Hz rate. This repetitiveness correlated and was in phase with low-frequency electromagnetic fluctuations. The emissions were associat ... Mozer, F.~S.; Vasko, I.~Y.; Verniero, J.~L.; Published by: \apjl Published on: sep YEAR: 2021 DOI: 10.3847/2041-8213/ac2259 Solar Coronal Waves; Solar wind; 1995; 1534; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Parker Data Used |
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The role of solar wind expansion in generating whistler waves is investigated using the EB-iPic3D code, which models solar wind expansion self-consistently within a fully kinetic semi-implicit approach. The simulation is initialized with an electron velocity distribution function modeled after observations of the Parker Solar Probe during its first perihelion at 0.166 au, consisting of a dense core and an antisunward strahl. This distribution function is initially stable with respect to kinetic instabilities. Expansion drive ... Micera, A.; Zhukov, A.~N.; opez, R.~A.; Boella, E.; Tenerani, A.; Velli, M.; Lapenta, G.; Innocenti, M.~E.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac1067 Solar wind; Plasma astrophysics; Space plasmas; 1534; 1261; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
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The first computations of the compressible energy transfer rate from \raisebox-0.5ex\textasciitilde0.2 up to \raisebox-0.5ex\textasciitilde1.7 au is obtained using Parker Solar Probe (PSP), Time History of Events and Macroscale Interactions during Substorms (THEMIS), and Mars Atmosphere and Volatile EvolutioN (MAVEN) observations. Using a recently derived exact relation for isothermal magnetohydrodynamics turbulence, the compressible energy cascade rate, \ensuremath\varepsilon$_C$, is computed for hundred of events at differ ... es, Andr\; Sahraoui, F.; Hadid, L.~Z.; Huang, S.~Y.; Romanelli, N.; Galtier, S.; DiBraccio, G.; Halekas, J.; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac0af5 Solar wind; Fast solar wind; Slow solar wind; Interplanetary physics; 1534; 1872; 1873; 827; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Parker Data Used |
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Context. The analysis of the thermal part of velocity distribution functions (VDFs) is fundamentally important for understanding the kinetic physics that governs the evolution and dynamics of space plasmas. However, calculating the proton core, beam, and \ensuremath\alpha-particle parameters for large data sets of VDFs is a time-consuming and computationally demanding process that always requires supervision by a human expert. \ Aims: We developed a machine learning tool that can extract proton core, beam, and \ensuremath\al ... Vech, D.; Stevens, M.~L.; Paulson, K.~W.; Malaspina, D.~M.; Case, A.~W.; Klein, K.~G.; Kasper, J.~C.; Published by: \aap Published on: jun YEAR: 2021 DOI: 10.1051/0004-6361/202141063 Parker Data Used; turbulence; plasmas; waves; methods: statistical; Physics - Space Physics; Astrophysics - Instrumentation and Methods for Astrophysics; Physics - Plasma Physics |
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Various forms of exact laws governing magnetohydrodynamic (MHD) turbulence have been derived either in the incompressibility limit, or for isothermal compressible flows. Here we propose a more general method that allows us to obtain such laws for any turbulent isentropic flow (i.e., constant entropy). We demonstrate that the known MHD exact laws (incompressible and isothermal) and the new (polytropic) one can be obtained as specific cases of the general law when the corresponding closure equation is stated. We also recover a ... Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/ac0337 Solar wind; Solar Physics; Parker Data Used; Magnetohydrodynamics; Plasma astrophysics; Plasma physics; interplanetary turbulence; 1534; 1476; 1964; 1261; 2089; 830; Physics - Plasma Physics; Physics - Fluid Dynamics |
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Turbulent Generation of Magnetic Switchbacks in the Alfv\ enic Solar Wind One of the most important early results from the Parker Solar Probe (PSP) is the ubiquitous presence of magnetic switchbacks, whose origin is under debate. Using a three-dimensional direct numerical simulation of the equations of compressible magnetohydrodynamics from the corona to 40 solar radii, we investigate whether magnetic switchbacks emerge from granulation-driven Alfv\ en waves and turbulence in the solar wind. The simulated solar wind is an Alfv\ enic slow-solar- wind stream with a radial profile consistent with var ... Shoda, Munehito; Chandran, Benjamin; Cranmer, Steven; Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/abfdbc Space plasmas; Solar wind; interplanetary turbulence; Parker Data Used; Magnetohydrodynamical simulations; Alfven waves; 1544; 1534; 830; 1966; 23; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Large Amplitude Switchback Turbulence: Possible Magnetic Velocity Alignment Structures Switchbacks are widely acknowledged phenomena observed by the Parker Solar Probe and appear to occur in patches. Previous studies focused on the fluctuations at the magnetic reversals. However, the nature of the fluctuations inside the switchbacks remains unknown. Here we utilize the magnetic field data and plasma data measured by the Parker Solar Probe in the first four encounters. We investigate the fluctuations in the switchback intervals of 100 s with $B_R 0$ at every instant and compare them to the fluctuations in the n ... Wu, Honghong; Tu, Chuanyi; Wang, Xin; Yang, Liping; Published by: The Astrophysical Journal Published on: 06/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abec6c Parker Data Used; Solar wind; interplanetary turbulence; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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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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Wave-particle energy transfer directly observed in an ion cyclotron wave Context. The first studies with Parker Solar Probe (PSP) data have made significant progress toward understanding of the fundamental properties of ion cyclotron waves in the inner heliosphere. The survey mode particle measurements of PSP, however, did not make it possible to measure the coupling between electromagnetic fields and particles on the time scale of the wave periods. Vech, D.; Martinovic, M.; Klein, K.; Malaspina, D.; Bowen, T.; Verniero, J.; Paulson, K.; de Wit, Dudok; Kasper, J.; Huang, J.; Stevens, M.; Case, A.; Korreck, K.; Mozer, F.; Goodrich, K.; Bale, S.; Whittlesey, P.; Livi, R.; Larson, D.; Pulupa, M.; Bonnell, J.; Harvey, P.; Goetz, K.; MacDowall, R.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039296 Solar wind; waves; turbulence; Physics - Space Physics; Physics - Plasma Physics; Parker Data Used |
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Turbulent Proton Heating Rate in the Solar Wind from 545 R Various remote sensing observations have been used so far to probe the turbulent properties of the solar wind. Using the recently reported density modulation indices that are derived using angular broadening observations of Crab Nebula during 19522013, we measured the solar wind proton heating using the kinetic Alfvn wave dispersion equation. The estimated heating rates vary from 1.58 1014 to 1.01 108 erg cm3 s1 in the heliocentric distance range of 545 R. Further, we found that he ... Raja, Sasikumar; Subramanian, Prasad; Ingale, Madhusudan; Ramesh, R.; Maksimovic, Milan; Published by: The Astrophysical Journal Published on: 06/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abfcd1 Solar wind; Radio occultation; 1534; 1351; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Between the base of the solar corona at $r=r_\textrm b$ and the Alfvén critical point at $r=r_\textrm A$, where $r$ is heliocentric distance, the solar-wind density decreases by a factor $ \mathop > \limits_∼ 10^5$, but the plasma temperature varies by a factor of only a few. In this paper, I show that such quasi-isothermal evolution out to $r=r_\textrm A$ is a generic property of outflows powered by reflection-driven Alfvén-wave (AW) turbulence, in which outward-propagating AWs partially reflect, and counter-propagating ... Published by: Journal of Plasma Physics Published on: 05/2021 YEAR: 2021 DOI: 10.1017/S0022377821000052 astrophysical plasmas; space plasma physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
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On the violation of the zeroth law of turbulence in space plasmas The zeroth law of turbulence states that, for fixed energy input into large-scale motions, the statistical steady state of a turbulent system is independent of microphysical dissipation properties. This behaviour, which is fundamental to nearly all fluid-like systems from industrial processes to galaxies, occurs because nonlinear processes generate smaller and smaller scales in the flow, until the dissipation - no matter how small - can thermalise the energy input. Using direct numerical simulations and theoretical arguments ... Meyrand, R.; Squire, J.; Schekochihin, A.; Dorland, W.; Published by: Journal of Plasma Physics Published on: 05/2021 YEAR: 2021 DOI: 10.1017/S0022377821000489 space plasma physics; astrophysical plasmas; plasma nonlinear phenomena; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Nonlinear Sciences - Chaotic Dynamics; Physics - Plasma 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 |
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Subproton-scale Intermittency in Near-Sun Solar Wind Turbulence Observed by the Parker Solar Probe High time-resolution solar wind magnetic field data are employed to study statistics describing intermittency near the first perihelion (∼35.6 R⊙) of the Parker Solar Probe mission. A merged data set employing two instruments on the FIELDS suite enables broadband estimation of higher-order moments of magnetic field increments, with five orders established with reliable accuracy. The duration, cadence, and low noise level of the data permit evaluation of scale dependence of the observed intermittency from the i ... Chhiber, Rohit; Matthaeus, William; Bowen, Trevor; Bale, Stuart; Published by: The Astrophysical Journal Published on: 04/2021 YEAR: 2021 DOI: 10.3847/2041-8213/abf04e Parker Data Used; Solar wind; interplanetary turbulence; Magnetohydrodynamics; Space plasmas; 1534; 830; 1964; 1544; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Geophysics; Physics - Plasma Physics |
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Observations of plasma waves by the Fields Suite and of electrons by the Solar Wind Electrons Alphas and Protons Investigation on the Parker Solar Probe provide strong evidence for pitch angle scattering of strahl-energy electrons by narrowband whistler-mode waves at radial distances less than ∼0.3 au. We present two example intervals of a few hours each that include eight waveform captures with whistler-mode waves and 26 representative electron distributions that are examined in detail. Two were narrow, seventeen were cle ... Cattell, C.; Breneman, A.; Dombeck, J.; Short, B.; Wygant, J.; Halekas, J.; Case, Tony; Kasper, J.; Larson, D.; Stevens, Mike; Whittesley, P.; Bale, S.; de Wit, Dudok; Goodrich, K.; MacDowall, R.; Moncuquet, M.; Malaspina, D.; Pulupa, M.; Published by: The Astrophysical Journal Published on: 04/2021 YEAR: 2021 DOI: 10.3847/2041-8213/abefdd Parker Data Used; Solar wind; Space plasmas; Plasma astrophysics; Interplanetary physics; Interplanetary particle acceleration; 1534; 1544; 1261; 827; 826; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Electron Acceleration during Macroscale Magnetic Reconnection The first self-consistent simulations of electron acceleration during magnetic reconnection in a macroscale system are presented. Consistent with solar flare observations, the spectra of energetic electrons take the form of power laws that extend more than two decades in energy. The drive mechanism for these nonthermal electrons is Fermi reflection in growing and merging magnetic flux ropes. A strong guide field suppresses the production of nonthermal electrons by weakening the Fermi drive mechanism. For a weak guide field t ... Arnold, H.; Drake, J.; Swisdak, M.; Guo, F.; Dahlin, J.; Chen, B.; Fleishman, G.; Glesener, L.; Kontar, E.; Phan, T.; Shen, C.; Published by: Physical Review Letters Published on: 04/2021 YEAR: 2021 DOI: 10.1103/PhysRevLett.126.135101 Parker Data Used; Physics - Plasma Physics; Astrophysics - High Energy Astrophysical Phenomena |
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Switchbacks Explained: Super-Parker Fields—The Other Side of the Sub-Parker Spiral We provide a simple geometric explanation for the source of switchbacks and associated large and one-sided transverse flows in the solar wind observed by the Parker Solar Probe (PSP). The more radial, sub-Parker spiral structure of the heliospheric magnetic field observed previously by Ulysses, ACE, and STEREO is created within rarefaction regions where footpoint motion from the source of fast into slow wind at the Sun creates a magnetic fieldline connection across solar wind speed shear. Conversely, when footpoints move fro ... Published by: The Astrophysical Journal Published on: 03/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abd4e6 Parker Data Used; Active Solar Corona; Solar wind; Solar Coronal Waves; Solar coronal loops; Solar coronal holes; Solar coronal plumes; Solar magnetic fields; interplanetary magnetic fields; Solar spicules; 1988; 1534; 1995; 1485; 1484; 2039; 1503; 824; 1525; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; 85 |
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Source-dependent Properties of Two Slow Solar Wind States Two states of the slow solar wind are identified from in situ measurements by the Parker Solar Probe (PSP) inside 50 solar radii from the Sun. At such distances the wind measured by PSP has not yet undergone significant transformation related to the expansion and propagation of the wind. We focus in this study on the properties of the quiet solar wind with no magnetic switchbacks. The two states differ by their plasma beta, flux, and magnetic pressure. PSP s magnetic connectivity established with potential field source surfa ... Griton, Lea; Rouillard, Alexis; Poirier, Nicolas; Issautier, Karine; Moncuquet, Michel; Pinto, Rui; Published by: The Astrophysical Journal Published on: 03/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abe309 Parker Data Used; Slow solar wind; Solar wind; Solar coronal holes; Solar coronal streamers; 1873; 1534; 1484; 1486; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Characteristics of Magnetic Holes in the Solar Wind Revealed by Parker Solar Probe Yu, L.; Huang, S.~Y.; Yuan, Z.~G.; Jiang, K.; Xiong, Q.~Y.; Xu, S.~B.; Wei, Y.~Y.; Zhang, J.; Zhang, Z.~H.; Published by: \apj Published on: 02/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abb9a8 Solar wind; Solar Physics; interplanetary magnetic fields; Solar magnetic fields; 1534; 1476; 824; 1503; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Harmonic Radio Emission in Randomly Inhomogeneous Plasma In the present paper, we describe a theoretical model of the generation of harmonic emissions of type III solar radio bursts. The goal of our study is to fully take into account the most efficient physical processes involved in the generation of harmonic electromagnetic emission via nonlinear coupling of Langmuir waves in randomly inhomogeneous plasma of solar wind ( $l+l^\prime \to t$ ). We revisit the conventional mechanism of coalescence of primarily generated and back-scattered Langmuir waves in quasihomogeneous plasma. ... Tkachenko, Anna; Krasnoselskikh, Vladimir; Voshchepynets, Andrii; Published by: The Astrophysical Journal Published on: 02/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abd2bd Parker Data Used; Solar wind; interplanetary turbulence; Solar Coronal Waves; 1534; 830; 1995; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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The random walk of magnetic field lines is an important ingredient in understanding how the connectivity of the magnetic field affects the spatial transport and diffusion of charged particles. As solar energetic particles propagate away from near-solar sources, they interact with the fluctuating magnetic field, which modifies their distributions. We develop a formalism in which the differential equation describing the field line random walk contains both effects due to localized magnetic displacements and a non-stochastic co ... Chhiber, Rohit; Ruffolo, David; Matthaeus, William; Usmanov, Arcadi; Tooprakai, Paisan; Chuychai, Piyanate; Goldstein, Melvyn; Published by: The Astrophysical Journal Published on: 02/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abd7f0 Parker Data Used; Solar energetic particles; interplanetary turbulence; interplanetary magnetic fields; Solar wind; 1491; 830; 824; 1534; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
| 2020 |
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Tearing Modes in Partially Ionized Astrophysical Plasma Pucci, Fulvia; Singh, Alkendra; Tenerani, Anna; Velli, Marco; Published by: \apjl Published on: 11/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abc0e7 Parker Data Used; Solar magnetic reconnection; Plasma astrophysics; Space plasmas; Collision processes; 1504; 1261; 1544; 2065; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Novel aspects of cosmic ray diffusion in synthetic magnetic turbulence Dundovic, Andrej; Pezzi, Oreste; Blasi, Pasquale; Evoli, Carmelo; Matthaeus, William; Published by: \prd Published on: 11/2020 YEAR: 2020 DOI: 10.1103/PhysRevD.102.103016 Parker Data Used; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics; Physics - Space Physics |
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Oblique Tearing Mode Instability: Guide Field and Hall Effect Shi, Chen; Velli, Marco; Pucci, Fulvia; Tenerani, Anna; Innocenti, Maria; Published by: \apj Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb6fa Parker Data Used; Solar magnetic reconnection; Plasma physics; Magnetohydrodynamics; 1504; 2089; 1964; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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The Electromagnetic Signature of Outward Propagating Ion-scale Waves First results from the Parker Solar Probe (PSP) mission have revealed ubiquitous coherent ion-scale waves in the inner heliosphere, which are signatures of kinetic wave-particle interactions and fluid instabilities. However, initial studies of the circularly polarized ion-scale waves observed by PSP have only thoroughly analyzed magnetic field signatures, precluding a determination of solar wind frame propagation direction and intrinsic wave polarization. A comprehensive determination of wave properties requires measureme ... Bowen, Trevor; Bale, Stuart; Bonnell, J.; Larson, Davin; Mallet, Alfred; McManus, Michael; Mozer, Forrest; Pulupa, Marc; Vasko, Ivan; Verniero, J.; Published by: The Astrophysical Journal Published on: 08/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab9f37 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar Probe Plus; Solar wind; Space plasmas |
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Critical Balance and the Physics of Magnetohydrodynamic Turbulence Oughton, S.; Matthaeus, W.~H.; Published by: \apj Published on: 07/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab8f2a Parker Data Used; 830; 1544; 1534; 2129; 23; 1964; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics |
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The nature of the plasma wave modes around the ion kinetic scales in highly Alfv\ enic slow solar wind turbulence is investigated using data from the NASA\textquoterights Parker Solar Probe taken in the inner heliosphere, at 0.18 au from the Sun. The joint distribution of the normalized reduced magnetic helicity σm (θRB, τ) is obtained, where θRB is the angle between the local mean magnetic field and the radial direction and τ is the temporal scale. Two populations around ion scales a ... Huang, S; Zhang, J.; Sahraoui, F.; He, J.; Yuan, Z.; es, Andr\; Hadid, L.; Deng, X.; Jiang, K.; Yu, L.; Xiong, Q; Wei, Y; Xu, S.; Bale, S.; Kasper, J.; Published by: The Astrophysical Journal Published on: 07/2020 YEAR: 2020 DOI: 10.3847/2041-8213/ab9abb 1261; 1534; 1544; 1693; 1873; 23; 711; 824; 830; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Constraining Ion-Scale Heating and Spectral Energy Transfer in Observations of Plasma Turbulence We perform a statistical study of the turbulent power spectrum at inertial and kinetic scales observed during the first perihelion encounter of the Parker Solar Probe. We find that often there is an extremely steep scaling range of the power spectrum just above the ion-kinetic scales, similar to prior observations at 1 A.U., with a power-law index of around -4 . Based on our measurements, we demonstrate that either a significant (\>50 \%) fraction of the total turbulent energy flux is dissipated in this range of scales ... Bowen, Trevor; Mallet, Alfred; Bale, Stuart; Bonnell, J.; Case, Anthony; Chandran, Benjamin; Chasapis, Alexandros; Chen, Christopher; Duan, Die; de Wit, Thierry; Goetz, Keith; Halekas, Jasper; Harvey, Peter; Kasper, J.; Korreck, Kelly; Larson, Davin; Livi, Roberto; MacDowall, Robert; Malaspina, David; McManus, Michael; Pulupa, Marc; Stevens, Michael; Whittlesey, Phyllis; Published by: Physical Review Letters Published on: 07/2020 YEAR: 2020 DOI: 10.1103/PhysRevLett.125.025102 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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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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Tearing Instability and Periodic Density Perturbations in the Slow Solar Wind In contrast with the fast solar wind, which originates in coronal holes, the source of the slow solar wind is still debated. Often intermittent and enriched with low first ionization potential elements\textemdashakin to what is observed in closed coronal loops\textemdashthe slow wind could form in bursty events nearby helmet streamers. Slow winds also exhibit density perturbations that have been shown to be periodic and could be associated with flux ropes ejected from the tip of helmet streamers, as shown recently by the ... Réville, Victor; Velli, Marco; Rouillard, Alexis; Lavraud, Benoit; Tenerani, Anna; Shi, Chen; Strugarek, Antoine; Published by: The Astrophysical Journal Published on: 05/2020 YEAR: 2020 DOI: 10.3847/2041-8213/ab911d Astrophysics - Solar and Stellar Astrophysics; Magnetohydrodynamics; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Slow solar wind; Solar magnetic reconnection; Solar Probe Plus; Solar wind |
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Electron Energy Partition across Interplanetary Shocks. III. Analysis Wilson, Lynn; Chen, Li-Jen; Wang, Shan; Schwartz, Steven; Turner, Drew; Stevens, Michael; Kasper, Justin; Osmane, Adnane; Caprioli, Damiano; Bale, Stuart; Pulupa, Marc; Salem, Chadi; Goodrich, Katherine; Published by: \apj Published on: 04/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab7d39 Parker Data Used; 1534; 829; 310; 1997; 1544; 1261; 2089; 826; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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In-situ Switchback Formation in the Expanding Solar Wind Recent near-Sun solar-wind observations from Parker Solar Probe have found a highly dynamic magnetic environment, permeated by abrupt radial-field reversals, or "switchbacks." We show that many features of the observed turbulence are reproduced by a spectrum of Alfv\ enic fluctuations advected by a radially expanding flow. Starting from simple superpositions of low-amplitude outward-propagating waves, our expanding-box compressible magnetohydrodynamic simulations naturally develop switchbacks because (i) the normalized am ... Squire, J.; Chandran, B.; Meyrand, R.; Published by: The Astrophysical Journal Published on: 03/2020 YEAR: 2020 DOI: 10.3847/2041-8213/ab74e1 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Enhanced Energy Transfer Rate in Solar Wind Turbulence Observed near the Sun from Parker Solar Probe Direct evidence of an inertial-range turbulent energy cascade has been provided by spacecraft observations in heliospheric plasmas. In the solar wind, the average value of the derived heating rate near 1 au is \~10\ 3\ Jkg\ -1\ s\ -1\ \ \~103Jkg-1s-1 , an amount sufficient to account for observed departures from adiabatic expansion. Parker Solar Probe, even during its first solar encounter, offers the first opportunity to compute, in a similar fashion, a fluid-scale energy decay rate, mu ... Bandyopadhyay, Riddhi; Goldstein, M.; Maruca, B.; Matthaeus, W.; Parashar, T.; Ruffolo, D.; Chhiber, R.; Usmanov, A.; Chasapis, A.; Qudsi, R.; Bale, Stuart; Bonnell, J.; de Wit, Thierry; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Kasper, J.; Korreck, K.; Case, A.; Stevens, M.; Whittlesey, P.; Larson, D.; Livi, R.; Klein, K.; Velli, M.; Raouafi, N.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5dae Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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The Enhancement of Proton Stochastic Heating in the Near-Sun Solar Wind Stochastic heating (SH) is a nonlinear heating mechanism driven by the violation of magnetic moment invariance due to large-amplitude turbulent fluctuations producing diffusion of ions toward higher kinetic energies in the direction perpendicular to the magnetic field. It is frequently invoked as a mechanism responsible for the heating of ions in the solar wind. Here, we quantify for the first time the proton SH rate Q⊥ at radial distances from the Sun as close as 0.16 au, using measurements from the first tw ... Martinovic, Mihailo; Klein, Kristopher; Kasper, Justin; Case, Anthony; Korreck, Kelly; Larson, Davin; Livi, Roberto; Stevens, Michael; Whittlesey, Phyllis; Chandran, Benjamin; Alterman, Ben; Huang, Jia; Chen, Christopher; Bale, Stuart; Pulupa, Marc; Malaspina, David; Bonnell, John; Harvey, Peter; Goetz, Keith; de Wit, Thierry; MacDowall, Robert; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab527f Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Solar Probe Plus |
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The Evolution and Role of Solar Wind Turbulence in the Inner Heliosphere The first two orbits of the Parker Solar Probe spacecraft have enabled the first in situ measurements of the solar wind down to a heliocentric distance of 0.17 au (or 36 R\ ⊙\ \ R⊙ ). Here, we present an analysis of this data to study solar wind turbulence at 0.17 au and its evolution out to 1 au. While many features remain similar, key differences at 0.17 au include increased turbulence energy levels by more than an order of magnitude, a magnetic field spectral index of -3/2 matching that of t ... Chen, C.; Bale, S.; Bonnell, J.; Borovikov, D.; Bowen, T.; Burgess, D.; Case, A.; Chandran, B.; de Wit, Dudok; Goetz, K.; Harvey, P.; Kasper, J.; Klein, K.; Korreck, K.; Larson, D.; Livi, R.; MacDowall, R.; Malaspina, D.; Mallet, A.; McManus, M.; Moncuquet, M.; Pulupa, M.; Stevens, M.; Whittlesey, P.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab60a3 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Parker Solar Probe In Situ Observations of Magnetic Reconnection Exhausts during Encounter 1 Magnetic reconnection in current sheets converts magnetic energy into particle energy. The process may play an important role in the acceleration and heating of the solar wind close to the Sun. Observations from Parker Solar Probe (PSP) provide a new opportunity to study this problem, as it measures the solar wind at unprecedented close distances to the Sun. During the first orbit, PSP encountered a large number of current sheets in the solar wind through perihelion at 35.7 solar radii. We performed a comprehensive survey ... Phan, T.; Bale, S.; Eastwood, J.; Lavraud, B.; Drake, J.; Oieroset, M.; Shay, M.; Pulupa, M.; Stevens, M.; MacDowall, R.; Case, A.; Larson, D.; Kasper, J.; Whittlesey, P.; Szabo, A.; Korreck, K.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; Horbury, T.; Livi, R.; Malaspina, D.; Paulson, K.; Raouafi, N.; Velli, M.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab55ee Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Kinetic-scale Spectral Features of Cross Helicity and Residual Energy in the Inner Heliosphere In this work, we present the first results from the flux angle (FA) operation mode of the Faraday Cup instrument on board the Parker Solar Probe (PSP). The FA mode allows rapid measurements of phase space density fluctuations close to the peak of the proton velocity distribution function with a cadence of 293 Hz. This approach provides an invaluable tool for understanding kinetic-scale turbulence in the solar wind and solar corona. We describe a technique to convert the phase space density fluctuations into vector velocit ... Vech, Daniel; Kasper, Justin; Klein, Kristopher; Huang, Jia; Stevens, Michael; Chen, Christopher; Case, Anthony; Korreck, Kelly; Bale, Stuart; Bowen, Trevor; Whittlesey, Phyllis; Livi, Roberto; Larson, Davin; Malaspina, David; Pulupa, Marc; Bonnell, John; Harvey, Peter; Goetz, Keith; de Wit, Thierry; MacDowall, Robert; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab60a2 Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Observations at 1 au have confirmed that enhancements in measured energetic-particle (EP) fluxes are statistically associated with "rough" magnetic fields, i.e., fields with atypically large spatial derivatives or increments, as measured by the Partial Variance of Increments (PVI) method. One way to interpret this observation is as an association of the EPs with trapping or channeling within magnetic flux tubes, possibly near their boundaries. However, it remains unclear whether this association is a transport or local ef ... Bandyopadhyay, Riddhi; Matthaeus, W.; Parashar, T.; Chhiber, R.; Ruffolo, D.; Goldstein, M.; Maruca, B.; Chasapis, A.; Qudsi, R.; McComas, D.; Christian, E.; Szalay, J.; Joyce, C.; Giacalone, J.; Schwadron, N.; Mitchell, D.; Hill, M.; Wiedenbeck, M.; McNutt, R.; Desai, M.; Bale, Stuart; Bonnell, J.; de Wit, Thierry; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Velli, M.; Kasper, J.; Korreck, K.; Stevens, M.; Case, A.; Raouafi, N.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab6220 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Observations of Heating along Intermittent Structures in the Inner Heliosphere from PSP Data The solar wind proton temperature at 1 au has been found to be correlated with small-scale intermittent magnetic structures, i.e., regions with enhanced temperature are associated with coherent structures, such as current sheets. Using Parker Solar Probe data from the first encounter, we study this association using measurements of the radial proton temperature, employing the partial variance of increments (PVI) technique to identify intermittent magnetic structures. We observe that the probability density functions of hi ... Qudsi, R.; Maruca, B.; Matthaeus, W.; Parashar, T.; Bandyopadhyay, Riddhi; Chhiber, R.; Chasapis, A.; Goldstein, Melvyn; Bale, S.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Kasper, J.; Korreck, K.; Case, A.; Stevens, M.; Whittlesey, P.; Larson, D.; Livi, R.; Velli, M.; Raouafi, N.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5c19 Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Magnetic field fluctuations in the solar wind are commonly observed to follow a power-law spectrum. Near proton-kinetic scales, a spectral break occurs that is commonly interpreted as a transition to kinetic turbulence. However, this transition is not yet entirely understood. By studying the scaling of the break with various plasma properties, it may be possible to constrain the processes leading to the onset of kinetic turbulence. Using data from the Parker Solar Probe, we measure the proton-scale break over a range of h ... Duan, Die; Bowen, Trevor; Chen, Christopher; Mallet, Alfred; He, Jiansen; Bale, Stuart; Vech, Daniel; Kasper, J.; Pulupa, Marc; Bonnell, John; Case, Anthony; de Wit, Thierry; Goetz, Keith; Harvey, Peter; Korreck, Kelly; Larson, Davin; Livi, Roberto; MacDowall, Robert; Malaspina, David; Stevens, Michael; Whittlesey, Phyllis; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab672d Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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The Solar Probe Cup on the Parker Solar Probe Solar Probe Cup (SPC) is a Faraday cup instrument on board NASA\textquoterights Parker Solar Probe (PSP) spacecraft designed to make rapid measurements of thermal coronal and solar wind plasma. The spacecraft is in a heliocentric orbit that takes it closer to the Sun than any previous spacecraft, allowing measurements to be made where the coronal and solar wind plasma is being heated and accelerated. The SPC instrument was designed to be pointed directly at the Sun at all times, allowing the solar wind (which is flowing p ... Case, A.; Kasper, Justin; Stevens, Michael; Korreck, Kelly; Paulson, Kristoff; Daigneau, Peter; Caldwell, Dave; Freeman, Mark; Henry, Thayne; Klingensmith, Brianna; Bookbinder, J.; Robinson, Miles; Berg, Peter; Tiu, Chris; Wright, K.; Reinhart, Matthew; Curtis, David; Ludlam, Michael; Larson, Davin; Whittlesey, Phyllis; Livi, Roberto; Klein, Kristopher; c, Mihailo; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5a7b Astrophysics - Instrumentation and Methods for Astrophysics; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Density Fluctuations in the Solar Wind Based on Type III Radio Bursts Observed by Parker Solar Probe Radio waves are strongly scattered in the solar wind, so that their apparent sources seem to be considerably larger and shifted than the actual ones. Since the scattering depends on the spectrum of density turbulence, a better understanding of the radio wave propagation provides indirect information on the relative density fluctuations, ϵ=⟨δn⟩/⟨n⟩\ ϵ=⟨δn⟩/⟨n⟩ , at the effective turbulence scale length. Here, we analyzed 30 type III bursts detected by Parker Sola ... Krupar, Vratislav; Szabo, Adam; Maksimovic, Milan; Kruparova, Oksana; Kontar, Eduard; Balmaceda, Laura; Bonnin, Xavier; Bale, Stuart; Pulupa, Marc; Malaspina, David; Bonnell, John; Harvey, Peter; Goetz, Keith; de Wit, Thierry; MacDowall, Robert; Kasper, Justin; Case, Anthony; Korreck, Kelly; Larson, Davin; Livi, Roberto; Stevens, Michael; Whittlesey, Phyllis; Hegedus, Alexander; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab65bd Astrophysics - Earth and Planetary Astrophysics; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
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Scattering of Energetic Electrons by Heat-flux-driven Whistlers in Flares Roberg-Clark, G.~T.; Agapitov, O.; Drake, J.~F.; Swisdak, M.; Published by: \apj Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab5114 Parker Data Used; solar flares; Plasma physics; 1496; 2089; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Electron Energy Partition across Interplanetary Shocks. II. Statistics A statistical analysis of 15,210 electron velocity distribution function (VDF) fits, observed within \textpm2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented. This is the second in a three-part series on electron VDFs near IP shocks. The electron velocity moment statistics for the dense, low-energy core, tenuous, hot halo, and field-aligned beam/strahl are a statistically significant list of values illustrated with both histograms and tabular lists for reference and baselines in future w ... Wilson, Lynn; Chen, Li-Jen; Wang, Shan; Schwartz, Steven; Turner, Drew; Stevens, Michael; Kasper, Justin; Osmane, Adnane; Caprioli, Damiano; Bale, Stuart; Pulupa, Marc; Salem, Chadi; Goodrich, Katherine; Published by: The Astrophysical Journal Supplement Series Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4365/ab5445 Astrophysics - Solar and Stellar Astrophysics; Interplanetary particle acceleration; Interplanetary shocks; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar coronal mass ejection shocks; Solar coronal mass ejections; Solar Probe Plus; Solar wind; Space plasmas |
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Self-induced Scattering of Strahl Electrons in the Solar Wind We investigate the scattering of strahl electrons by microinstabilities as a mechanism for creating the electron halo in the solar wind. We develop a mathematical framework for the description of electron-driven microinstabilities and discuss the associated physical mechanisms. We find that an instability of the oblique fast-magnetosonic/whistler (FM/W) mode is the best candidate for a microinstability that scatters strahl electrons into the halo. We derive approximate analytic expressions for the FM/W instability thresho ... Verscharen, Daniel; Chandran, Benjamin; Jeong, Seong-Yeop; Salem, Chadi; Pulupa, Marc; Bale, Stuart; Published by: The Astrophysical Journal Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab4c30 Astrophysics - Solar and Stellar Astrophysics; instabilities; parker solar probe; Physics - Geophysics; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; Sun: corona; turbulence; waves |
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Large-scale parallel electric fields and return currents in a global simulation model Arnold, H.; Drake, J.~F.; Swisdak, M.; Dahlin, J.; Published by: Physics of Plasmas Published on: 10/2019 YEAR: 2019 DOI: 10.1063/1.5120373 Parker Data Used; Physics - Plasma Physics; Physics - Space Physics |
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Zhang, Qile; Drake, J.~F.; Swisdak, M.; Published by: Physics of Plasmas Published on: 10/2019 YEAR: 2019 DOI: 10.1063/1.5121782 Parker Data Used; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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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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Singh, K.~A.~P.; Pucci, Fulvia; Tenerani, Anna; Shibata, Kazunari; Hillier, Andrew; Velli, Marco; Published by: \apj Published on: 08/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab2b99 Parker Data Used; magnetic reconnection; magnetohydrodynamics: MHD; plasmas; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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