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Found 620 entries in the Bibliography.
Showing entries from 201 through 250
| 2021 |
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The Sunward Electron Deficit: A Telltale Sign of the Sun s Electric Potential As the Parker Solar Probe explores new regions of the inner heliosphere, it travels ever deeper into the electric potential of the Sun. In the near-Sun environment, a new feature of the electron distribution emerges, in the form of a deficit in the sunward suprathermal population. The lower boundary of this deficit forms a cutoff in phase space, at an energy determined by the electric potential drop between the observation point and the outer heliosphere. We explore the characteristics of the sunward deficit and the associat ... Halekas, J.~S.; Ber\vci\vc, L.; Whittlesey, P.; Larson, D.~E.; Livi, R.; Berthomier, M.; Kasper, J.~C.; Case, A.~W.; Stevens, M.~L.; Bale, S.~D.; MacDowall, R.~J.; Pulupa, M.~P.; Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/ac096e |
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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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Parker Solar Probe Enters the Magnetically Dominated Solar Corona The high temperatures and strong magnetic fields of the solar corona form streams of solar wind that expand through the Solar System into interstellar space. At 09:33 UT on 28 April 2021 Parker Solar Probe entered the magnetized atmosphere of the Sun 13 million km above the photosphere, crossing below the Alfv\ en critical surface for five hours into plasma in casual contact with the Sun with an Alfv\ en Mach number of 0.79 and magnetic pressure dominating both ion and electron pressure. The spectrum of turbulence below the ... Kasper, J.~C.; Klein, K.~G.; Lichko, E.; Huang, Jia; Chen, C.~H.~K.; Badman, S.~T.; Bonnell, J.; Whittlesey, P.~L.; Livi, R.; Larson, D.; Pulupa, M.; Rahmati, A.; Stansby, D.; Korreck, K.~E.; Stevens, M.; Case, A.~W.; Bale, S.~D.; Maksimovic, M.; Moncuquet, M.; Goetz, K.; Halekas, J.~S.; Malaspina, D.; Raouafi, Nour; Szabo, A.; MacDowall, R.; Velli, Marco; de Wit, Thierry; Zank, G.~P.; Published by: \prl Published on: dec YEAR: 2021 DOI: 10.1103/PhysRevLett.127.255101 |
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We report analysis of sub-Alfv\ enic magnetohydrodynamic (MHD) perturbations in the low-\ensuremath\beta radial-field solar wind employing the Parker Solar Probe spacecraft data from 2018 October 31 to November 12. We calculate wavevectors using the singular value decomposition method and separate MHD perturbations into three eigenmodes (Alfv\ en, fast, and slow modes) to explore the properties of sub-Alfv\ enic perturbations and the role of compressible perturbations in solar wind heating. The MHD perturbations show a high ... Zhao, S.~Q.; Yan, Huirong; Liu, Terry; Liu, Mingzhe; Shi, Mijie; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2ffe Parker Data Used; 1534; 830; 1964; 1544; 1636; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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One of the striking observations from the Parker Solar Probe (PSP) spacecraft is the prevalence in the inner heliosphere of large amplitude, Alfv\ enic magnetic field reversals termed switchbacks. These $\delta B_R/B\sim \mathcal O (1$ ) fluctuations occur over a range of timescales and in patches separated by intervals of quiet, radial magnetic field. We use measurements from PSP to demonstrate that patches of switchbacks are localized within the extensions of plasma structures originating at the base of the corona. These ... Bale, S.~D.; Horbury, T.~S.; Velli, M.; Desai, M.~I.; Halekas, J.~S.; McManus, M.~D.; Panasenco, O.; Badman, S.~T.; Bowen, T.~A.; Chandran, B.~D.~G.; Drake, J.~F.; Kasper, J.~C.; Laker, R.; Mallet, A.; Matteini, L.; Phan, T.~D.; Raouafi, N.~E.; Squire, J.; Woodham, L.~D.; Woolley, T.; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2d8c Parker Data Used; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Domains of Magnetic Pressure Balance in Parker Solar Probe Observations of the Solar Wind The Parker Solar Probe (PSP) spacecraft is performing the first in situ exploration of the solar wind within 0.2 au of the Sun. Initial observations confirmed the Alfv\ enic nature of aligned fluctuations of the magnetic field B and velocity V in solar wind plasma close to the Sun, in domains of nearly constant magnetic field magnitude \ensuremath\mid B \ensuremath\mid, i.e., approximate magnetic pressure balance. Such domains are interrupted by particularly strong fluctuations, including but not limited to radial field (pol ... Ruffolo, David; Ngampoopun, Nawin; Bhora, Yash; Thepthong, Panisara; Pongkitiwanichakul, Peera; Matthaeus, William; Chhiber, Rohit; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2ee3 Parker Data Used; 1534; 830; 1544; 824; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Simulation results from a global magnetohydrodynamic model of the solar corona and solar wind are compared with Parker Solar Probe (PSP) observations during its first five orbits. The fully three- dimensional model is based on Reynolds-averaged mean-flow equations coupled with turbulence-transport equations. The model includes the effects of electron heat conduction, Coulomb collisions, turbulent Reynolds stresses, and heating of protons and electrons via a turbulent cascade. Turbulence-transport equations for average turbul ... Chhiber, Rohit; Usmanov, Arcadi; Matthaeus, William; Goldstein, Melvyn; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac1ac7 Parker Data Used; 830; 1534; 824; 1483; 1477; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Internal Structure of the 2019 April 2 CME We present the first analysis of internal coronal mass ejection (CME) structure observed very close to the Sun by the Wide-field Imager for Solar PRobe (WISPR) instrument on board the Parker Solar Probe (PSP). The transient studied here is a CME observed during PSP s second perihelion passage on 2019 April 2, when PSP was only 40 R $_\ensuremath\odot$ from the Sun. The CME was also well observed from 1 au by the STEREO-A spacecraft, which tracks the event all the way from the Sun to 1 au. However, PSP/WISPR observes internal ... Wood, Brian; Braga, Carlos; Vourlidas, Angelos; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2aab Parker Data Used; 1534; 310; 825; Astrophysics - Solar and Stellar Astrophysics |
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Interaction between Multiple Current Sheets and a Shock Wave: 2D Hybrid Kinetic Simulations Particle acceleration behind a shock wave due to interactions between magnetic islands in the heliosphere has attracted attention in recent years. The downstream acceleration may yield a continuous increase of particle flux downstream of the shock wave. Although it is not obvious how the downstream magnetic islands are produced, it has been suggested that current sheets are involved in the generation of magnetic islands due to their interaction with a shock wave. We perform 2D hybrid kinetic simulations to investigate the in ... Nakanotani, M.; Zank, G.~P.; Zhao, L.; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2e06 |
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MHD and Ion Kinetic Waves in Field-aligned Flows Observed by Parker Solar Probe Parker Solar Probe (PSP) observed predominately Alfv\ enic fluctuations in the solar wind near the Sun where the magnetic field tends to be radially aligned. In this paper, two magnetic- field-aligned solar wind flow intervals during PSP s first two orbits are analyzed. Observations of these intervals indicate strong signatures of parallel/antiparallel-propagating waves. We utilize multiple analysis techniques to extract the properties of the observed waves in both magnetohydrodynamic (MHD) and kinetic scales. At the MHD sca ... Zhao, L.; Zank, G.~P.; He, J.~S.; Telloni, D.; Adhikari, L.; Nakanotani, M.; Kasper, J.~C.; Bale, S.~D.; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac28fb Parker Data Used; 1534; 23; 830; 824 |
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Daily Variations of Plasma Density in the Solar Streamer Belt Improved space weather diagnostics depend critically on improving our understanding of the evolution of the slow solar wind in the streamer belts near the Sun. Recent innovations in tomography techniques are opening a new window on this complex environment. In this work, a new time-dependent technique is applied to COR2A/Solar Terrestrial Relations Observatory observations from a period near solar minimum (2018 November 11) for heliocentric distances of 4-8 R $_\ensuremath\odot$. For the first time, we find density variation ... Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac1799 Parker Data Used; 1486; 1483; 1477; 1534; 1873; 313; 1043; 1916 |
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Signatures of Type III Solar Radio Bursts from Nanoflares: Modeling There is a wide consensus that the ubiquitous presence of magnetic reconnection events and the associated impulsive heating (nanoflares) are strong candidates for solving the solar coronal heating problem. Whether nanoflares accelerate particles to high energies like full-sized flares is unknown. We investigate this question by studying the type III radio bursts that the nanoflares may produce on closed loops. The characteristic frequency drifts that type III bursts exhibit can be detected using a novel application of the ti ... Chhabra, Sherry; Klimchuk, James; Gary, Dale; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2364 Parker Data Used; 1522; 1491; 1504; 1339; 1993; 1485; Astrophysics - Solar and Stellar Astrophysics |
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The fluctuations observed in the slow solar wind at 1 au by the WIND spacecraft are shown by recent studies to consist of mainly magnetic-field directional turning and magnetic-velocity alignment structure (MVAS). How these structures are created has been a question because the nature of the fluctuations in the near-Sun region remains unknown. Here, we present an analysis of the measurements in the slow solar wind from 0.1-0.3 au by Parker Solar Probe during its first six orbits. We present the distributions in the $C_\mathr ... Wu, Honghong; Tu, Chuanyi; Wang, Xin; Yang, Liping; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac3331 |
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Solar energetic particle heavy ion properties in the widespread event of 2020 November 29 Context. Following a multi-year minimum of solar activity, a solar energetic particle event on 2020 Nov. 29 was observed by multiple spacecraft covering a wide range of solar longitudes including ACE, the Solar Terrestrial Relations Observatory-A, and the recently launched Parker Solar Probe and Solar Orbiter. \ Aims: Multi-point observations of a solar particle event, combined with remote-sensing imaging of flaring, shocks, and coronal mass ejections allows for a global picture of the event to be synthesized, and made avail ... Mason, G.~M.; Cohen, C.~M.~S.; Ho, G.~C.; Mitchell, D.~G.; Allen, R.~C.; Hill, M.~E.; Andrews, G.~B.; Berger, L.; Boden, S.; Böttcher, S.; Cernuda, I.; Christian, E.~R.; Cummings, A.~C.; Davis, A.~J.; Desai, M.~I.; De Nolfo, G.~A.; Eldrum, S.; Elftmann, R.; Kollhoff, A.; Giacalone, J.; omez-Herrero, R.; Hayes, J.; Janitzek, N.~P.; Joyce, C.~J.; Korth, A.; Kühl, P.; Kulkarni, S.~R.; Labrador, A.~W.; Lara, Espinosa; Lees, W.~J.; Leske, R.~A.; Mall, U.; Martin, C.; in, Mart\; Matthaeus, W.~H.; McComas, D.~J.; McNutt, R.~L.; Mewaldt, R.~A.; Mitchell, J.~G.; Pacheco, D.; Espada, Parra; Prieto, M.; Rankin, J.~S.; Ravanbakhsh, A.; iguez-Pacheco, Rodr\; Polo, Rodr\; Roelof, E.~C.; anchez-Prieto, S.; Schlemm, C.~E.; Schwadron, N.~A.; Seifert, H.; Stone, E.~C.; Szalay, J.~R.; Terasa, J.~C.; Tyagi, K.; von Forstner, J.~L.; Wiedenbeck, M.~E.; Wimmer-Schweingruber, R.~F.; Xu, Z.~G.; Yedla, M.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202141310 Parker Data Used; acceleration of particles; Sun: abundances; Sun: flares; Sun: particle emission |
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\ Aims: We use multi-spacecraft observations of individual type III radio bursts to calculate the directivity of the radio emission. We compare these data to the results of ray-tracing simulations of the radio-wave propagation and probe the plasma properties of the inner heliosphere. \ Methods: We used ray-tracing simulations of radio-wave propagation with anisotropic scattering on density inhomogeneities to study the directivity of radio emissions. Simultaneous observations of type III radio bursts by four widely separated ... Musset, S.; Maksimovic, M.; Kontar, E.; Krupar, V.; Chrysaphi, N.; Bonnin, X.; Vecchio, A.; Cecconi, B.; Zaslavsky, A.; Issautier, K.; Bale, S.~D.; Pulupa, M.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140998 Parker Data Used; Sun: radio radiation; scattering; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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PSP/IS\ensuremath\odotIS observations of the 29 November 2020 solar energetic particle event \ Aims: On 29 November 2020, at 12:34 UT, active region 12790 erupted with an M4.4 class flare and a 1700 km s$^\ensuremath-1$ coronal mass ejection. Parker Solar Probe (PSP) was completing its seventh orbit around the Sun and was located at 0.8 au when the Integrated Science Investigation of the Sun (IS\ensuremath\odotIS) measured the ensuing mid- sized solar energetic particle (SEP) event. Not only was this the first SEP event with heavy ions above 10 MeV nuc$^\ensuremath-1$ to be measured by IS\ensuremath\odotIS, it was a ... Cohen, C.~M.~S.; Christian, E.~R.; Cummings, A.~C.; Davis, A.~J.; Desai, M.~I.; De Nolfo, G.~A.; Giacalone, J.; Hill, M.~E.; Joyce, C.~J.; Labrador, A.~W.; Leske, R.~A.; Matthaeus, W.~H.; McComas, D.~J.; McNutt, R.~L.; Mewaldt, R.~A.; Mitchell, D.~G.; Mitchell, J.~G.; Rankin, J.~S.; Roelof, E.~C.; Schwadron, N.~A.; Stone, E.~C.; Szalay, J.~R.; Wiedenbeck, M.~E.; Vourlidas, A.; Bale, S.~D.; Pulupa, M.; MacDowall, R.~J.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140967 Parker Data Used; Sun: particle emission; Sun: activity; solar-terrestrial relations |
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First Solar Orbiter observation of the Alfv\ enic slow wind and identification of its solar source Context. Turbulence dominated by large-amplitude, nonlinear Alfv\ en-like fluctuations mainly propagating away from the Sun is ubiquitous in high-speed solar wind streams. Recent studies have demontrated that slow wind streams may also show strong Alfv\ enic signatures, especially in the inner heliosphere. \ Aims: The present study focuses on the characterisation of an Alfv\ enic slow solar wind interval observed by Solar Orbiter between 14 and 18 July 2020 at a heliocentric distance of 0.64 AU. \ Methods: Our analysis is ba ... Amicis, R.; Bruno, R.; Panasenco, O.; Telloni, D.; Perrone, D.; Marcucci, M.~F.; Woodham, L.; Velli, M.; De Marco, R.; Jagarlamudi, V.; Coco, I.; Owen, C.; Louarn, P.; Livi, S.; Horbury, T.; e, Andr\; Angelini, V.; Evans, V.; Fedorov, A.; Genot, V.; Lavraud, B.; Matteini, L.; Müller, D.; Brien, H.; Pezzi, O.; Rouillard, A.~P.; Sorriso-Valvo, L.; Tenerani, A.; Verscharen, D.; Zouganelis, I.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140938 Parker Data Used; Interplanetary medium; Solar wind; methods: data analysis; magnetohydrodynamics (MHD); turbulence; Sun: general |
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\ Aims: Solar Orbiter (SolO) was launched on February 9, 2020, allowing us to study the nature of turbulence in the inner heliopshere. We investigate the evolution of anisotropic turbulence in the fast and slow solar wind in the inner heliosphere using the nearly incompressible magnetohydrodynamic (NI MHD) turbulence model and SolO measurements. \ Methods: We calculated the two dimensional (2D) and the slab variances of the energy in forward and backward propagating modes, the fluctuating magnetic energy, the fluctuating kin ... Adhikari, L.; Zank, G.~P.; Zhao, L.; Telloni, D.; Horbury, T.~S.; Brien, H.; Evans, V.; Angelini, V.; Owen, C.~J.; Louarn, P.; Fedorov, A.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140672 |
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Context. Solar Orbiter, the new-generation mission dedicated to solar and heliospheric exploration, was successfully launched on February 10, 2020, 04:03 UTC from Cape Canaveral. During its first perihelion passage in June 2020, two successive interplanetary coronal mass ejections (ICMEs), propagating along the heliospheric current sheet (HCS), impacted the spacecraft. \ Aims: This paper addresses the investigation of the ICMEs encountered by Solar Orbiter on June 7\ensuremath-8, 2020, from both an observational and a modeli ... Telloni, D.; Scolini, C.; Möstl, C.; Zank, G.~P.; Zhao, L.; Weiss, A.~J.; Reiss, M.~A.; Laker, R.; Perrone, D.; Khotyaintsev, Y.; Steinvall, K.; Sorriso-Valvo, L.; Horbury, T.~S.; Wimmer-Schweingruber, R.~F.; Bruno, R.; Amicis, R.; De Marco, R.; Jagarlamudi, V.~K.; Carbone, F.; Marino, R.; Stangalini, M.; Nakanotani, M.; Adhikari, L.; Liang, H.; Woodham, L.~D.; Davies, E.~E.; Hietala, H.; Perri, S.; omez-Herrero, R.; iguez-Pacheco, Rodr\; Antonucci, E.; Romoli, M.; Fineschi, S.; Maksimovic, M.; Sou\vcek, J.; Chust, T.; Kretzschmar, M.; Vecchio, A.; Müller, D.; Zouganelis, I.; Winslow, R.~M.; Giordano, S.; Mancuso, S.; Susino, R.; Ivanovski, S.~L.; Messerotti, M.; Brien, H.; Evans, V.; Angelini, V.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140648 Parker Data Used; magnetohydrodynamics (MHD); Sun: coronal mass ejections (CMEs); Sun: evolution; Sun: heliosphere; Solar wind; solar-terrestrial relations |
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Probing Upflowing Regions in the Quiet Sun and Coronal Holes Recent observations from Parker Solar Probe have revealed that the solar wind has a highly variable structure. How this complex behaviour is formed in the solar corona is not yet known, since it requires omnipresent fluctuations, which constantly emit material to feed the wind. In this article we analyse 14 upflow regions in the solar corona to find potential sources for plasma flow. The upflow regions are derived from spectroscopic data from the EUV Imaging Spectrometer (EIS) on board Hinode determining their Doppler veloci ... Schwanitz, Conrad; Harra, Louise; Raouafi, Nour; Sterling, Alphonse; Vacas, Alejandro; Iniesta, Jose; arez, David; Hara, Hirohisa; Published by: \solphys Published on: dec YEAR: 2021 DOI: 10.1007/s11207-021-01915-0 Parker Data Used; Corona; structures; Coronal holes; Jets; Astrophysics - Solar and Stellar Astrophysics |
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Momentous Crossing of a Solar Boundary The Parker Solar Probe has entered, for the first time, the Sun s magnetic atmosphere, where it started to gather data that could help researchers solve some of the greatest mysteries of solar physics. Published by: Physics Online Journal Published on: dec YEAR: 2021 DOI: 10.1103/Physics.14.177 |
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How to Survive Flying Too Close to the Sun The Parker Solar Probe has flown through the Sun s atmosphere\textemdashan unforgiving environment that poses a number of engineering challenges. Published by: Physics Online Journal Published on: dec YEAR: 2021 DOI: 10.1103/Physics.14.176 |
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Space weather: the solar perspective The Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space Weather relevant phenomena, coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and solar wind stream interaction regions (SIR). With the advent of the STEREO mis ... Published by: Living Reviews in Solar Physics Published on: dec YEAR: 2021 DOI: 10.1007/s41116-021-00030-3 Parker Data Used; space weather; Solar Physics; CMEs; flares; SEPs; Dynamic corona; magnetic field; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Spacecraft propagation tools describe the motion of near-Earth objects and interplanetary probes using Newton s theory of gravity supplemented with the approximate general relativistic n-body Einstein-Infeld-Hoffmann equations of motion. With respect to the general theory of relativity and the long-standing recommendations of the International Astronomical Union for astrometry, celestial mechanics and metrology, we believe modern orbitography software is now reaching its limits in terms of complexity. In this paper, we prese ... Leary, Joseph; Barriot, Jean-Pierre; Published by: Celestial Mechanics and Dynamical Astronomy Published on: dec YEAR: 2021 DOI: 10.1007/s10569-021-10051-7 Parker Data Used; General relativity; Non-gravitational forces; Symplectic integration |
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A Provably Positive, Divergence-free Constrained Transport Scheme for the Simulation of Solar Wind In this paper, we present a provably positive, divergence-free constrained transport (CT) scheme to simulate the steady-state solar wind ambient with the three-dimensional magnetohydrodynamics numerical model. The positivity can be lost in two ways: one way is in the reconstruction process, and the other is in the updating process when the variables are advanced to the next time step. We adopt a self-adjusting strategy to bring the density and pressure into the permitted range in the reconstruction process, and use modified ... Zhang, Man; Feng, Xueshang; Liu, Xiaojing; Yang, Liping; Published by: \apjs Published on: dec YEAR: 2021 DOI: 10.3847/1538-4365/ac1e29 Parker Data Used; Solar wind; Magnetohydrodynamical simulations; 1534; 1966 |
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Geometry of Magnetic Fluctuations near the Sun from the Parker Solar Probe Solar wind magnetic fluctuations exhibit anisotropy due to the presence of a mean magnetic field in the form of the Parker spiral. Close to the Sun, direct measurements were not available until the recently launched Parker Solar Probe (PSP) mission. The nature of the anisotropy and geometry of the magnetic fluctuations play a fundamental role in dissipation processes and in the transport of energetic particles in space. Using PSP data, we present measurements of the geometry and anisotropy of the inner heliosphere magnetic f ... Bandyopadhyay, R.; McComas, D.~J.; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac3486 Parker Data Used; 1534; 830; 994; 1483; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Switchback-like structures observed by Solar Orbiter Context. Rapid polarity reversals of the radial heliospheric magnetic field were discovered by Ulysses and they are now frequently observed as a common near-Sun phenomenon by NASA s Parker Solar Probe (PSP). Other solar wind missions, including ESA-NASA Solar Orbiter (SolO), also observe similar phenomena. The nature of these fluctuations is unclear, and the relation between the switchbacks observed near the Sun and similar events observed at 1 AU is unknown. \ Aims: We make a detailed case study of the SolO plasma and m ... Fedorov, A.; Louarn, P.; Owen, C.~J.; Horbury, T.~S.; Prech, L.; Durovcova, T.; Barthe, A.; Rouillard, A.~P.; Kasper, J.~C.; Bale, S.~D.; Bruno, R.; Brien, H.; Evans, V.; Angelini, V.; Larson, D.; Livi, R.; Lavraud, B.; Andre, N.; Genot, V.; Penou, E.; Mele, G.; Fortunato, V.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202141246 |
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The first widespread solar energetic particle event observed by Solar Orbiter on 2020 November 29 Context. On 2020 November 29, the first widespread solar energetic particle (SEP) event of solar cycle 25 was observed at four widely separated locations in the inner (\ensuremath\lesssim1 AU) heliosphere. Relativistic electrons as well as protons with energies > 50 MeV were observed by Solar Orbiter (SolO), Parker Solar Probe, the Solar Terrestrial Relations Observatory (STEREO)-A and multiple near- Earth spacecraft. The SEP event was associated with an M4.4 class X-ray flare and accompanied by a coronal mass ejection and a ... Kollhoff, A.; Kouloumvakos, A.; Lario, D.; Dresing, N.; omez-Herrero, R.; ia, Rodr\; Malandraki, O.~E.; Richardson, I.~G.; Posner, A.; Klein, K.; Pacheco, D.; Klassen, A.; Heber, B.; Cohen, C.~M.~S.; Laitinen, T.; Cernuda, I.; Dalla, S.; Lara, Espinosa; Vainio, R.; Köberle, M.; Kühl, R.; Xu, Z.~G.; Berger, L.; Eldrum, S.; Brüdern, M.; Laurenza, M.; Kilpua, E.~J.; Aran, A.; Rouillard, A.~P.; ik, Bu\vc\; Wijsen, N.; Pomoell, J.; Wimmer-Schweingruber, R.~F.; Martin, C.; Böttcher, S.~I.; von Forstner, J.~L.; Terasa, J.; Boden, S.; Kulkarni, S.~R.; Ravanbakhsh, A.; Yedla, M.; Janitzek, N.; iguez-Pacheco, Rodr\; Mateo, Prieto; Prieto, S.; Espada, Parra; Polo, Rodr\; in, Mart\; Carcaboso, F.; Mason, G.~M.; Ho, G.~C.; Allen, R.~C.; Andrews, Bruce; Schlemm, C.~E.; Seifert, H.; Tyagi, K.; Lees, W.~J.; Hayes, J.; Bale, S.~D.; Krupar, V.; Horbury, T.~S.; Angelini, V.; Evans, V.; Brien, H.; Maksimovic, M.; Khotyaintsev, Yu.; Vecchio, A.; Steinvall, K.; Asvestari, E.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140937 Parker Data Used; Sun: particle emission; Sun: heliosphere; Sun: coronal mass ejections (CMEs); Sun: flares; Interplanetary medium |
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Context. Solar Orbiter was launched on 10 February 2020 with the purpose of investigating solar and heliospheric physics using a payload of instruments designed for both remote and in situ studies. Similar to the recently launched Parker Solar Probe, and unlike earlier missions, Solar Orbiter carries instruments designed to measure low-frequency DC electric fields. \ Aims: In this paper, we assess the quality of the low-frequency DC electric field measured by the Radio and Plasma Waves instrument (RPW) on Solar Orbiter. In p ... Steinvall, K.; Khotyaintsev, Yu.; Cozzani, G.; Vaivads, A.; Yordanova, E.; Eriksson, A.~I.; Edberg, N.~J.~T.; Maksimovic, M.; Bale, S.~D.; Chust, T.; Krasnoselskikh, V.; Kretzschmar, M.; Lorfèvre, E.; Plettemeier, D.; Sou\vcek, J.; Steller, M.; ak, \vS.; Vecchio, A.; Horbury, T.~S.; Brien, H.; Evans, V.; Fedorov, A.; Louarn, P.; enot, V.; e, Andr\; Lavraud, B.; Rouillard, A.~P.; Owen, C.~J.; Published by: \aap Published on: dec YEAR: 2021 DOI: 10.1051/0004-6361/202140855 Parker Data Used; Solar wind; plasmas; magnetic reconnection; methods: data analysis; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Turbulence transport in the solar corona: Theory, modeling, and Parker Solar Probe A primary goal of the Parker Solar Probe (PSP) Mission is to answer the outstanding question of how the solar corona plasma is heated to the high temperatures needed for the acceleration of the solar wind. Various heating mechanisms have been suggested, but one that is gaining increasing credence is associated with the dissipation of low frequency magnetohyrodynamic (MHD) turbulence. However, the MHD turbulence models come in several flavors: one in which outwardly propagating Alfv\ en waves experience reflection from the la ... Zank, G.~P.; Zhao, L.; Adhikari, L.; Telloni, D.; Kasper, J.~C.; Bale, S.~D.; Published by: Physics of Plasmas Published on: aug YEAR: 2021 DOI: 10.1063/5.0055692 |
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The Formation and Lifetime of Outflows in a Solar Active Region Active regions are thought to be one contributor to the slow solar wind. Upflows in EUV coronal spectral lines are routinely observed at their boundaries, and provide the most direct way for upflowing material to escape into the heliosphere. The mechanisms that form and drive these upflows, however, remain to be fully characterized. It is unclear how quickly they form, or how long they exist during their lifetimes. They could be initiated low in the atmosphere during magnetic flux emergence, or as a response to processes occ ... Brooks, David; Harra, Louise; Bale, Stuart; Barczynski, Krzysztof; Mandrini, Cristina; Polito, Vanessa; Warren, Harry; Published by: \apj Published on: aug YEAR: 2021 DOI: 10.3847/1538-4357/ac0917 Solar Physics; Slow solar wind; Solar active regions; Solar energetic particles; 1476; 1873; 1974; 1491; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used |
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We present the first Parker Solar Probe mission (PSP)-observed coronal mass ejection (CME) that hits a second spacecraft before the end of the PSP encounter, providing an excellent opportunity to study short-term CME evolution. The CME was launched from the Sun on 2019 October 10 and was measured in situ at PSP on 2019 October 13 and at STEREO-A on 2019 October 14. The small, but not insignificant, radial (\raisebox-0.5ex\textasciitilde0.15 au) and longitudinal (\raisebox-0.5ex\textasciitilde8\textdegree) separation between ... Winslow, Reka; Lugaz, No\; Scolini, Camilla; Galvin, Antoinette; Published by: \apj Published on: aug YEAR: 2021 DOI: 10.3847/1538-4357/ac0821 Solar coronal mass ejections; Heliosphere; 310; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics; Parker Data Used |
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Near-Sun Switchback Boundaries: Dissipation with Solar Distance The most surprising result from the first solar encounters by the Parker Solar Probe (PSP) is the large amount of brief magnetic field reversals often referred to as switchbacks. Switchbacks have previously been observed further downstream in the solar wind by spacecraft such as Helios 2 at 62 R$_s$ from the Sun. However, these observations lack a distinct proton temperature increase detected inside switchbacks by PSP, implying that they are evolving over time to eventually reach a pressure balance at the switchback boundari ... Rasca, Anthony; Farrell, William; MacDowall, Robert; Bale, Stuart; Kasper, Justin; Published by: \apj Published on: aug YEAR: 2021 DOI: 10.3847/1538-4357/ac079f The Sun; Solar wind; Solar Physics; 1693; 1534; 1476; Parker Data Used |
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We present a statistical analysis for the characteristics and spatial evolution of the interplanetary discontinuities (IDs) in the solar wind, from 0.13-0.9 au, by using the Parker Solar Probe measurements on Orbits 4 and 5. We collected 3948 IDs, including 2511 rotational discontinuities (RDs) and 557 tangential discontinuities (TDs), with the remnant unidentified. The statistical results show that (1) the ID occurrence rate decreases from 200 events per day at 0.13 au to 1 event per day at 0.9 au, following a spatial scali ... Liu, Y.~Y.; Fu, H.~S.; Cao, J.~B.; Liu, C.~M.; Wang, Z.; Guo, Z.~Z.; Xu, Y.; Bale, S.~D.; Kasper, J.~C.; Published by: \apj Published on: aug YEAR: 2021 DOI: 10.3847/1538-4357/ac06a1 Interplanetary discontinuities; Solar wind; interplanetary magnetic fields; Magnetohydrodynamics; 820; 1534; 824; 1964; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics; Parker Data Used |
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Context. The recent launches of Parker Solar Probe, Solar Orbiter (SO), and BepiColombo, along with several older spacecraft, have provided the opportunity to study the solar wind at multiple latitudes and distances from the Sun simultaneously. \ Aims: We take advantage of this unique spacecraft constellation, along with low solar activity across two solar rotations between May and July 2020, to investigate how the solar wind structure, including the heliospheric current sheet (HCS), varies with latitude. \ Methods: We visua ... Laker, R.; Horbury, T.~S.; Bale, S.~D.; Matteini, L.; Woolley, T.; Woodham, L.~D.; Stawarz, J.~E.; Davies, E.~E.; Eastwood, J.~P.; Owens, M.~J.; Brien, H.; Evans, V.; Angelini, V.; Richter, I.; Heyner, D.; Owen, C.~J.; Louarn, P.; Fedorov, A.; Published by: \aap Published on: aug YEAR: 2021 DOI: 10.1051/0004-6361/202140679 Sun: coronal mass ejections (CMEs); Solar wind; Sun: heliosphere; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used |
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The Parker Solar Probe (PSP) mission presents a unique opportunity to study the near-Sun solar wind closer than any previous spacecraft. During its fourth and fifth solar encounters, PSP had the same orbital trajectory, meaning that solar wind was measured at the same latitudes and radial distances. We identify two streams measured at the same heliocentric distance (\raisebox-0.5ex\textasciitilde0.13au) and latitude (\raisebox-0.5ex\textasciitilde-3.5$^○$) across these encounters to reduce spatial evolution effects. By com ... Woolley, Thomas; Matteini, Lorenzo; McManus, Michael; Ber\vci\vc, Laura; Badman, Samuel; Woodham, Lloyd; Horbury, Timothy; Bale, Stuart; Laker, Ronan; Stawarz, Julia; Larson, Davin; Published by: \mnras Published on: aug YEAR: 2021 DOI: 10.1093/mnras/stab2281 Sun: heliosphere; Solar wind; magnetic fields; Parker Data Used |
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Assessing the Role of Interchange Reconnection in Forming Switchbacks Abrupt deflections of the magnetic field in the solar wind, so called switchbacks, are frequently observed by the Parker Solar Probe (PSP) during its first two orbits and are believed to play an important role in unveiling the nature of solar corona heating and solar wind acceleration in the inner heliosphere. Many attempts were made recently to understand the nature of switchbacks. However, the origin, propagation, and evolution of switchbacks are still under debate. In this study, we attempt to use the linear theory of ... Liang, H.; Zank, G.~P.; Nakanotani, M.; Zhao, L.; Published by: \apj Published on: aug YEAR: 2021 DOI: 10.3847/1538-4357/ac0a73 Space plasmas; Solar wind; Solar magnetic fields; Parker Data Used; Solar magnetic reconnection; 1544; 1534; 1503; 1504 |
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In-situ measurements carried out by spacecraft in radial alignment are critical to advance our knowledge on the evolutionary behavior of coronal mass ejections (CMEs) and their magnetic structures during propagation through interplanetary space. Yet, the scarcity of radially aligned CME crossings restricts investigations on the evolution of CME magnetic structures to a few case studies, preventing a comprehensive understanding of CME complexity changes during propagation. In this Letter, we perform numerical simulations of C ... Scolini, Camilla; Winslow, Reka; Lugaz, No\; Poedts, Stefaan; Published by: \apjl Published on: aug YEAR: 2021 DOI: 10.3847/2041-8213/ac0d58 Solar coronal mass ejections; Solar wind; Parker Data Used; interplanetary magnetic fields; Corotating streams; 310; 1534; 824; 314; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Dynamics of nanodust in the vicinity of a stellar corona: Effect of plasma corotation Context. In the vicinity of the Sun or other stars, the motion of the coronal and stellar wind plasma must include some amount of corotation, which could affect the dynamics of charged dust particles. In the case of the Sun, this region is now investigated in situ by the Parker Solar Probe. Charged dust particles coming from the vicinity of the Sun can also reach, and possibly be detected by, the Solar Orbiter. \ Aims: We use numerical simulations and theoretical models to study the effect of plasma corotation on the motion ... Published by: \aap Published on: aug YEAR: 2021 DOI: 10.1051/0004-6361/202141048 Sun: heliosphere; Solar wind; acceleration of particles; Parker Data Used; Interplanetary medium; circumstellar matter |
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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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Flux Ropes, Turbulence, and Collisionless Perpendicular Shock Waves: High Plasma Beta Case With the onset of solar maximum and the expected increased prevalence of interplanetary shock waves, Parker Solar Probe is likely to observe numerous shocks in the next few years. An outstanding question that has received surprisingly little attention has been how turbulence interacts with collisionless shock waves. Turbulence in the supersonic solar wind is described frequently as a superposition of a majority 2D and a minority slab component. We formulate a collisional perpendicular shock-turbulence transmission problem in ... Zank, G.; Nakanotani, M.; Zhao, L.; Du, S.; Adhikari, L.; Che, H.; le Roux, J.; Published by: The Astrophysical Journal Published on: 06/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abf7c8 Interplanetary shocks; interplanetary turbulence; 829; 830; Parker Data Used |
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Analysis of energetic particle inner heliospheric spacecraft data increasingly suggests the existence of anomalous diffusion phenomena that should be addressed to achieve a better understanding of energetic particle transport and acceleration in the expanding solar wind medium. Related to this is fast-growing observational evidence supporting the long-standing prediction from magnetohydrodynamic (MHD) theory and simulations of the presence of an inner heliospheric, dominant quasi-two-dimensional MHD turbulence component that ... Published by: The Astrophysical Journal Published on: 06/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abf3c6 Interplanetary particle acceleration; Solar wind; Solar magnetic reconnection; 826; 1534; 1504; Parker Data Used |
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Time evolution of stream interaction region energetic particle spectra in the inner heliosphere We analyze an energetic proton event associated with a stream interaction region (SIR) that was observed at Parker Solar Probe on day 320 of 2018 when the spacecraft was just 0.34 AU from the Sun. Using the Integrated Science Investigation of the Sun instrument suite, we perform a spectral analysis of the event and show how the observed spectra evolve over the course of the event. We find that the spectra from the first day of the event are much more consistent with local acceleration at a weak compression, while spectra fro ... Joyce, C.; McComas, D.; Schwadron, N.; Christian, E.; Wiedenbeck, M.; McNutt, R.; Cohen, C.; Leske, R.; Mewaldt, R.; Stone, E.; Labrador, A.; Davis, A.; Cummings, A.; Mitchell, D.; Hill, M.; Roelof, E.; Allen, R.; Szalay, J.; Rankin, J.; Desai, M.; Giacalone, J.; Matthaeus, W.; Bale, S.; Kasper, J.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039330 acceleration of particles; Solar wind; magnetic fields; Parker Data Used |
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Energetic particle behavior in near-Sun magnetic field switchbacks from PSP Context. The observation of numerous magnetic switchbacks and associated plasma jets in Parker Solar Probe (PSP) during its first five orbits, particularly near the Sun, has attracted considerable attention. Switchbacks have been found to be systematically associated with correlated reversals in the direction of the propagation of Alfvénic fluctuations, as well as similar reversals of the electron strahl. Bandyopadhyay, R.; Matthaeus, W.; McComas, D.; Joyce, C.; Szalay, J.; Christian, E.; Giacalone, J.; Schwadron, N.; Mitchell, D.; Hill, M.; McNutt, R.; Desai, M.; Bale, S.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Kasper, J.; Stevens, M.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039800 Solar wind; magnetic fields; plasmas; turbulence; instabilities; waves; Parker Data Used |
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Context. Recent studies of the solar wind sunward of 0.25 AU reveal that it contains quiescent regions, with low-amplitude plasma and magnetic field fluctuations, and a magnetic field direction similar to the Parker spiral. The quiescent regions are thought to have a more direct magnetic connection to the solar corona than other types of solar wind, suggesting that waves or instabilities in the quiescent regions are indicative of the early evolution of the solar wind as it escapes the corona. The quiescent solar wind regions ... Malaspina, D.; Wilson, L.; Ergun, R.; Bale, S.; Bonnell, J.; Goodrich, K.; Goetz, K.; Harvey, P.; MacDowall, R.; Pulupa, M.; Halekas, J.; Case, A.; Kasper, J.; Larson, D.; Stevens, M.; Whittlesey, P.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202140449 |
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Context. Silicon solid-state detectors are commonly used for measuring the specific ionization, dE∕dx, in instruments designed for identifying energetic nuclei using the dE∕dx versus total energy technique in space and in the laboratory. The energy threshold and species resolution of the technique strongly depend on the thickness and thickness uniformity of these detectors. Wiedenbeck, M.; Burnham, J.; Cohen, C.; Cook, W.; Crabill, R.; Cummings, A.; Davis, A.; Kecman, B.; Labrador, A.; Leske, R.; Mewaldt, R.; Rankin, J.; Rusert, M.; Stone, E.; Christian, E.; Goodwin, P.; Link, J.; Nahory, B.; Shuman, S.; von Rosenvinge, T.; Tindall, C.; Black, H.; Bullough, M.; Clarke, N.; Glasson, V.; Greenwood, N.; Hawkins, C.; Johnson, T.; Newton, A.; Richardson, K.; Walsh, S.; Wilburn, C.; Birdwell, B.; Everett, d.; McComas, D.; Weidner, S.; Angold, N.; Schwadron, N.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039754 instrumentation: detectors; Sun: particle emission; acceleration of particles; space vehicles: instruments; Parker Data Used |
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Parker Solar Probe observations of He/H abundance variations in SEP events inside 0.5 au
Cohen, C.; Christian, E.; Cummings, A.; Davis, A.; Desai, M.; de Nolfo, G.; Giacalone, J.; Hill, M.; Joyce, C.; Labrador, A.; Leske, R.; Matthaeus, W.; McComas, D.; McNutt, R.; Mewaldt, R.; Mitchell, D.; Mitchell, J.; Rankin, J.; Roelof, E.; Schwadron, N.; Stone, E.; Szalay, J.; Wiedenbeck, M.; Vourlidas, A.; Bale, S.; Pulupa, M.; MacDowall, R.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039299 Sun: particle emission; Sun: activity; solar-terrestrial relations; Parker Data Used |
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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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The contribution of alpha particles to the solar wind angular momentum flux in the inner heliosphere Context. An accurate assessment of the Sun s angular momentum (AM) loss rate is an independent constraint for models that describe the rotation evolution of Sun-like stars. Finley, A.; McManus, M.; Matt, S.; Kasper, J.; Korreck, K.; Case, A.; Stevens, M.; Whittlesey, P.; Larson, D.; Livi, R.; Bale, S.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021 DOI: 10.1051/0004-6361/202039288 Solar wind; stars: evolution; stars: winds; outflows; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used |
