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Found 691 entries in the Bibliography.
Showing entries from 101 through 150
| 2022 |
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We report on the state of the corona over the minimum and ascending phases of Solar Cycle (SC) 25 on the basis of the temporal evolutions of its radiance and of the properties of coronal mass ejections (CMEs), as determined from white-light observations performed by the SOHO/LASCO-C2 coronagraph. These evolutions are further compared with those determined during the past two Solar Cycles using the same methods. The integrated radiance of the K-corona and the occurrence rate of CMEs closely track the indices/proxies of solar ... Lamy, Philippe; Gilardy, Hugo; Published by: \solphys Published on: oct YEAR: 2022 DOI: 10.1007/s11207-022-02057-7 Parker Data Used; Corona; K-corona; Activity; Astrophysics - Solar and Stellar Astrophysics |
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The Solar Probe ANalyzer-Ions on the Parker Solar Probe The Solar Probe ANalyzer for Ions (SPAN-I) onboard NASA s Parker Solar Probe spacecraft is an electrostatic analyzer with time-of- flight capabilities that measures the ion composition and three- dimensional distribution function of the thermal corona and solar-wind plasma. SPAN-I measures the energy per charge of ions in the solar wind from 2 eV to 30 keV with a field of view of 247.\textdegree5 \texttimes 120\textdegree while simultaneously separating H$^+$ from He$^++$ to develop 3D velocity distribution functions of indi ... Livi, Roberto; Larson, Davin; Kasper, Justin; Abiad, Robert; Case, A.~W.; Klein, Kristopher; Curtis, David; Dalton, Gregory; Stevens, Michael; Korreck, Kelly; Ho, George; Robinson, Miles; Tiu, Chris; Whittlesey, Phyllis; Verniero, Jaye; Halekas, Jasper; McFadden, James; Marckwordt, Mario; Slagle, Amanda; Abatcha, Mamuda; Rahmati, Ali; McManus, Michael; Published by: \apj Published on: oct YEAR: 2022 DOI: 10.3847/1538-4357/ac93f5 Parker Data Used; Heliosphere; The Sun; Solar Physics; 711; 1693; 1476 |
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Switchback deflections beyond the early parker solar probe encounters Switchbacks are Aflv\ enic fluctuations in the solar wind, which exhibit large rotations in the magnetic field direction. Observations from Parker Solar Probe s (PSP s) first two solar encounters have formed the basis for many of the described switchback properties and generation mechanisms. However, this early data may not be representative of the typical near-Sun solar wind, biasing our current understanding of these phenomena. One defining switchback property is the magnetic deflection direction. During the first solar en ... Laker, R.; Horbury, T.~S.; Matteini, L.; Bale, S.~D.; Stawarz, J.~E.; Woodham, L.~D.; Woolley, T.; Published by: \mnras Published on: nov YEAR: 2022 DOI: 10.1093/mnras/stac2477 Parker Data Used; Sun: magnetic fields; Sun: heliosphere; Solar wind; Physics - Space Physics |
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Reconciling Parker Solar Probe Observations and Magnetohydrodynamic Theory The Parker Solar Probe mission provides a unique opportunity to characterize several features of the solar wind at different heliocentric distances. Recent findings have shown a transition in the inertial range spectral and scaling properties around 0.4-0.5 au when moving away from the Sun. Here we provide, for the first time, how to reconcile these observational results on the radial evolution of the magnetic and velocity field fluctuations with two scenarios drawn from the magnetohydrodynamic theory. The observed breakdown ... Alberti, Tommaso; Benella, Simone; Consolini, Giuseppe; Stumpo, Mirko; Benzi, Roberto; Published by: \apjl Published on: nov YEAR: 2022 DOI: 10.3847/2041-8213/aca075 Parker Data Used; Solar wind; interplanetary turbulence; Magnetohydrodynamics; interplanetary magnetic fields; 1534; 830; 1964; 824; Astrophysics - Solar and Stellar Astrophysics; Nonlinear Sciences - Chaotic Dynamics; Physics - Plasma Physics; Physics - Space Physics |
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Observations of Quiescent Solar Wind Regions with Near-f $_ce$ Wave Activity In situ measurements in the near-Sun solar wind from the Parker Solar Probe have revealed the existence of quiescent solar wind regions: extended regions of solar wind with low-amplitude turbulent magnetic field fluctuations compared to adjacent regions. Identified through the study of harmonic waves near the electron cyclotron frequency (f $_ce$), these quiescent regions are shown to host a variety of plasma waves. The near-f $_ce$ harmonic waves are observed exclusively in quiescent regions, and as such, they can be used a ... Short, Benjamin; Malaspina, David; Halekas, Jasper; Romeo, Orlando; Verniero, J.~L.; Finley, Adam; Kasper, Justin; Rahmati, Ali; Bale, Stuart; Bonnell, John; Case, Anthony; de Wit, Thierry; Goetz, Keith; Goodrich, Katherine; Harvey, Peter; Korreck, Kelly; Larson, Davin; Livi, Roberto; MacDowall, Robert; Pulupa, Marc; Stevens, Michael; Whittlesey, Phyllis; Published by: \apj Published on: nov YEAR: 2022 DOI: 10.3847/1538-4357/ac97e4 Parker Data Used; Solar wind; interplanetary turbulence; Space plasmas; Solar magnetic fields; Heliosphere; 1534; 830; 1544; 1503; 711 |
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Observations from Parker Solar Probe s first five orbits are used to investigate the helioradial evolution of probability density functions (pdfs) of fluctuations of magnetic-field components between \raisebox-0.5ex\textasciitilde28 and 200 R $_\ensuremath\odot$. Transformation of the magnetic-field vector to a local mean-field coordinate system permits examination of anisotropy relative to the mean magnetic-field direction. Attention is given to effects of averaging-interval size. It is found that pdfs of the perpendicular ... Published by: \apj Published on: nov YEAR: 2022 DOI: 10.3847/1538-4357/ac9386 Parker Data Used; Solar wind; interplanetary magnetic fields; interplanetary turbulence; 1534; 824; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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In the present paper, we have studied nonlinear kinetic Alfv\ en waves (KAWs) in the vicinity of a null point. We have considered the nonlinearity due to ponderomotive effects associated with KAWs in the solar corona. A 3D model equation representing the dynamics of KAWs is developed in this null point scenario. Using numerical methods, we have solved the model equation for solar coronal parameters. The pseudospectral method and the finite difference method have been applied to tackle spatial integration and temporal evaluat ... Patel, G.; Pathak, N.; Uma, R.; Sharma, R.~P.; Published by: \solphys Published on: nov YEAR: 2022 DOI: 10.1007/s11207-022-02083-5 Parker Data Used; Solar corona heating-Sun: corona- turbulence; Wave; Null points |
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The Parker Solar Probe is braving extreme conditions to explore the mysterious solar corona, a region that harbors some of the most difficult-to-understand phenomena in astrophysics. Published by: Physics Today Published on: nov YEAR: 2022 DOI: 10.1063/PT.3.5120 |
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We examine in greater detail five events previously identified as being sources of strong transient coronal outflows in a solar polar region in Hinode/Extreme Ultraviolet (EUV) Imaging Spectrometer (EIS) Doppler data. Although relatively compact or faint and inconspicuous in Hinode/X-ray Telescope (XRT) soft-X-ray (SXR) images and in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) EUV images, we find that all of these events are consistent with being faint coronal X-ray jets. The evidence for this is that ... Sterling, Alphonse; Schwanitz, Conrad; Harra, Louise; Raouafi, Nour; Panesar, Navdeep; Moore, Ronald; Published by: \apj Published on: nov YEAR: 2022 DOI: 10.3847/1538-4357/ac9960 Parker Data Used; Solar filament eruptions; Solar corona; Solar x-ray emission; Solar extreme ultraviolet emission; 1981; 1483; 1536; 1493; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Ion Kinetics of Plasma Flows: Earth s Magnetosheath versus Solar Wind Revealing the formation, dynamics, and contribution to plasma heating of magnetic field fluctuations in the solar wind is an important task for heliospheric physics and for a general plasma turbulence theory. Spacecraft observations in the solar wind are limited to spatially localized measurements, so that the evolution of fluctuation properties with solar wind propagation is mostly studied via statistical analyses of data sets collected by different spacecraft at various radial distances from the Sun. In this study we inves ... Artemyev, A.~V.; Shi, C.; Lin, Y.; Nishimura, Y.; Gonzalez, C.; Verniero, J.; Wang, X.; Velli, M.; Tenerani, A.; Sioulas, N.; Published by: \apj Published on: nov YEAR: 2022 DOI: 10.3847/1538-4357/ac96e4 Parker Data Used; interplanetary turbulence; Solar wind; 830; 1534 |
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We investigate the effects of the evolutionary processes in the internal magnetic structure of two interplanetary coronal mass ejections (ICMEs) detected in situ between 2020 November 29 and December 1 by the Parker Solar Probe (PSP). The sources of the ICMEs were observed remotely at the Sun in EUV and subsequently tracked to their coronal counterparts in white light. This period is of particular interest to the community as it has been identified as the first widespread solar energetic particle event of solar cycle 25. The ... Nieves-Chinchilla, Teresa; Alzate, Nathalia; Cremades, Hebe; ia, Laura; Santos, Luiz; Narock, Ayris; Xie, Hong; Szabo, Adam; Palmerio, Erika; Krupar, Vratislav; Pulupa, Marc; Lario, David; Stevens, Michael; Wilson, Lynn; Kwon, Ryun-Young; Mays, Leila; St. Cyr, Chris; Hess, Phillip; Reeves, Katharine; Seaton, Daniel; Niembro, Tatiana; Bale, Stuart; Kasper, Justin; Published by: \apj Published on: may YEAR: 2022 DOI: 10.3847/1538-4357/ac590b Parker Data Used; Solar coronal mass ejections; Solar wind; Interplanetary physics; 310; 1534; 827; Astrophysics - Solar and Stellar Astrophysics |
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CMEs and SEPs During November-December 2020: A Challenge for Real-Time Space Weather Forecasting Predictions of coronal mass ejections (CMEs) and solar energetic particles (SEPs) are a central issue in space weather forecasting. In recent years, interest in space weather predictions has expanded to include impacts at other planets beyond Earth as well as spacecraft scattered throughout the heliosphere. In this sense, the scope of space weather science now encompasses the whole heliospheric system, and multipoint measurements of solar transients can provide useful insights and validations for prediction models. In this w ... Palmerio, Erika; Lee, Christina; Mays, Leila; Luhmann, Janet; Lario, David; anchez-Cano, Beatriz; Richardson, Ian; Vainio, Rami; Stevens, Michael; Cohen, Christina; Steinvall, Konrad; Möstl, Christian; Weiss, Andreas; Nieves-Chinchilla, Teresa; Li, Yan; Larson, Davin; Heyner, Daniel; Bale, Stuart; Galvin, Antoinette; Holmström, Mats; Khotyaintsev, Yuri; Maksimovic, Milan; Mitrofanov, Igor; Published by: Space Weather Published on: may YEAR: 2022 DOI: 10.1029/2021SW002993 Parker Data Used; coronal mass ejections; Solar energetic particles; space weather forecasts; MHD models; Inner heliosphere; Solar wind; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics; Physics - Space Physics |
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Many magnetic field switchbacks were detected by the Parker Solar Probe and their origin remains a puzzle. We did a superposed epoch analysis (SEA) to investigate the plasma characteristics in the vicinity of switchbacks and their radial evolution. SEA is good way to get the statistical average features of certain types of events that have obvious boundaries and different durations. For 55 events ranging from 1 to 30 min, the SEA results show that a small parcel of plasma is piling up in front of the reversed field, and ... Liu, Ruoyan; Liu, Yong; Huang, Jia; Huang, Zhaohui; Klecker, Berndt; Wang, Chi; Published by: Journal of Geophysical Research (Space Physics) Published on: may YEAR: 2022 DOI: 10.1029/2022JA030382 |
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The incompressible energy cascade rate in anisotropic solar wind turbulence Context. The presence of a magnetic guide field induces several types of anisotropy in solar wind turbulence. The energy cascade rate between scales in the inertial range depends strongly on the direction of this magnetic guide field, splitting the energy cascade according to the parallel and perpendicular directions with respect to magnetic guide field. \ Aims: Using more than two years of Parker Solar Probe (PSP) observations, the isotropy and anisotropy energy cascade rates are investigated. The variance and normalized fl ... es, Andr\; Sahraoui, F.; Huang, S.; Hadid, L.~Z.; Galtier, S.; Published by: \aap Published on: may YEAR: 2022 DOI: 10.1051/0004-6361/202142994 Parker Data Used; turbulence; magnetohydrodynamics (MHD); plasmas; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics |
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Multi-scale image preprocessing and feature tracking for remote CME characterization Coronal Mass Ejections (CMEs) influence the interplanetary environment over vast distances in the solar system by injecting huge clouds of fast solar plasma and energetic particles (SEPs). A number of fundamental questions remain about how SEPs are produced, but current understanding points to CME-driven shocks and compressions in the solar corona. At the same time, unprecedented remote and in situ (Parker Solar Probe, Solar Orbiter) solar observations are becoming available to constrain existing theories. Here we present a ... Stepanyuk, Oleg; Kozarev, Kamen; Nedal, Mohamed; Published by: Journal of Space Weather and Space Climate Published on: may YEAR: 2022 DOI: 10.1051/swsc/2022020 Parker Data Used; Coronal bright fronts; coronal mass ejections; image processing; eruptive filaments; CME; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Instrumentation and Methods for Astrophysics; Physics - Space Physics |
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We report observations of reconnection exhausts in the Heliospheric Current Sheet (HCS) during Parker Solar Probe Encounters 08 and 07, at 16 R$_s$ and 20 R$_s$, respectively. Heliospheric current sheet (HCS) reconnection accelerated protons to almost twice the solar wind speed and increased the proton core energy by a factor of \ensuremath\sim3, due to the Alfv\ en speed being comparable to the solar wind flow speed at these near-Sun distances. Furthermore, protons were energized to super-thermal energies. During E08, energ ... Phan, T.~D.; Verniero, J.~L.; Larson, D.; Lavraud, B.; Drake, J.~F.; Oieroset, M.; Eastwood, J.~P.; Bale, S.~D.; Livi, R.; Halekas, J.~S.; Whittlesey, P.~L.; Rahmati, A.; Stansby, D.; Pulupa, M.; MacDowall, R.~J.; Szabo, P.~A.; Koval, A.; Desai, M.; Fuselier, S.~A.; Velli, M.; Hesse, M.; Pyakurel, P.~S.; Maheshwari, K.; Kasper, J.~C.; Stevens, J.~M.; Case, A.~W.; Raouafi, N.~E.; Published by: \grl Published on: may YEAR: 2022 DOI: 10.1029/2021GL096986 Parker Data Used; magnetic reconnection; Particle acceleration; Solar wind; parker solar probe; heliospheric current sheet |
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Frequency Transition From Weak to Strong Turbulence in the Solar Wind During a specific time window while approaching the Sun, the longitudinal speed of Parker Solar Probe matches that of the Sun s rotation. The spacecraft therefore co-rotates with the Sun, and as long as it does so, it is immersed in the solar-wind plasma of the same flow tube. This unique feature of the Parker Solar Probe s orbital configuration is exploited in this work for the first time, to investigate the spectral properties of the turbulence of the same plasma stream, from large to small scales, very close to the Sun. S ... Published by: Frontiers in Astronomy and Space Sciences Published on: may YEAR: 2022 DOI: 10.3389/fspas.2022.917393 |
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Streamer-blowout coronal mass ejections (SBO-CMEs) are the dominant CME population during solar minimum. Although they are typically slow and lack clear low-coronal signatures, they can cause geomagnetic storms. With the aid of extrapolated coronal fields and remote observations of the off-limb low corona, we study the initiation of an SBO-CME preceded by consecutive CME eruptions consistent with a multi-stage sympathetic breakout scenario. From inner-heliospheric Parker Solar Probe (PSP) observations, it is evident that the ... Pal, Sanchita; Lynch, Benjamin; Good, Simon; Palmerio, Erika; Asvestari, Eleanna; Pomoell, Jens; Stevens, Michael; Kilpua, Emilia; Published by: Frontiers in Astronomy and Space Sciences Published on: may YEAR: 2022 DOI: 10.3389/fspas.2022.903676 Parker Data Used; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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We examine statistics of magnetic-field vector components to explore how intermittency evolves from near-Sun plasma to radial distances as large as 10 au. Statistics entering the analysis include autocorrelation, magnetic structure functions of the order of n (SF$_ n $), and scale-dependent kurtosis (SDK), each grouped in ranges of heliocentric distance. The Goddard Space Flight Center Space Physics Data Facility provides magnetic-field measurements for resolutions of 6.8 ms for Parker Solar Probe, 6 s for Helios, and 1.92 s ... Cuesta, Manuel; Parashar, Tulasi; Chhiber, Rohit; Matthaeus, William; Published by: \apjs Published on: mar YEAR: 2022 DOI: 10.3847/1538-4365/ac45fa Parker Data Used; Solar wind; interplanetary magnetic fields; Space plasmas; interplanetary turbulence; Interplanetary physics; 1534; 824; 1544; 830; 827; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Relativistic Particle Transport and Acceleration in Structured Plasma Turbulence We discuss the phenomenon of energization of relativistic charged particles in three-dimensional incompressible MHD turbulence and the diffusive properties of the motion of the same particles. We show that the random electric field induced by turbulent plasma motion leads test particles moving in a simulated box to be accelerated in a stochastic way, a second-order Fermi process. A small fraction of these particles happen to be trapped in large- scale structures, most likely formed due to the interaction of islands in the tu ... Pezzi, Oreste; Blasi, Pasquale; Matthaeus, William; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac5332 Parker Data Used; Magnetohydrodynamics; cosmic rays; Particle astrophysics; 1964; 329; 96; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics |
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Core Electron Heating by Triggered Ion Acoustic Waves in the Solar Wind Perihelion passes on Parker Solar Probe orbits 6-9 have been studied to show that solar wind core electrons emerged from 15 solar radii with a temperature of 55 \ensuremath\pm 5 eV, independent of the solar wind speed, which varied from 300 to 800 km s$^-1$. After leaving 15 solar radii and in the absence of triggered ion acoustic waves at greater distances, the core electron temperature varied with radial distance, R, in solar radii, as 1900R $^-4/3$ eV because of cooling produced by the adiabatic expansion. The coefficient ... Mozer, F.~S.; Bale, S.~D.; Cattell, C.~A.; Halekas, J.; Vasko, I.~Y.; Verniero, J.~L.; Kellogg, P.~J.; Published by: \apjl Published on: mar YEAR: 2022 DOI: 10.3847/2041-8213/ac5520 Parker Data Used; Solar corona; Solar wind; 1483; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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We use data from the first six encounters of the Parker Solar Probe and employ the partial variance of increments (PVI) method to study the statistical properties of coherent structures in the inner heliosphere with the aim of exploring physical connections between magnetic field intermittency and observable consequences such as plasma heating and turbulence dissipation. Our results support proton heating localized in the vicinity of, and strongly correlated with, magnetic structures characterized by PVI \ensuremath\geq 1. W ... Sioulas, Nikos; Velli, Marco; Chhiber, Rohit; Vlahos, Loukas; Matthaeus, William; Bandyopadhyay, Riddhi; Cuesta, Manuel; Shi, Chen; Bowen, Trevor; Qudsi, Ramiz; Stevens, Michael; Bale, Stuart; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4fc1 Parker Data Used; Solar wind; Space plasmas; Plasma astrophysics; 1534; 1544; 1261; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Langmuir-Slow Extraordinary Mode Magnetic Signature Observations with Parker Solar Probe Radio emission from interplanetary shocks, planetary foreshocks, and some solar flares occurs in the so-called plasma emission framework. The generally accepted scenario begins with electrostatic Langmuir waves that are driven by a suprathermal electron beam on the Landau resonance. These Langmuir waves then mode-convert to freely propagating electromagnetic emissions at the local plasma frequency f $_ pe $ and/or its harmonic 2f $_ pe $. However, the details of the physics of mode conversion are unclear, and so far the ... Larosa, A.; de Wit, Dudok; Krasnoselskikh, V.; Bale, S.~D.; Agapitov, O.; Bonnell, J.; Froment, C.; Goetz, K.; Harvey, P.; Halekas, J.; Kretzschmar, M.; MacDowall, R.; Malaspina, David; Moncuquet, M.; Niehof, J.; Pulupa, M.; Revillet, C.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4e85 Parker Data Used; Solar wind; Plasma physics; Space plasmas; 1534; 2089; 1544 |
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We present observations of \ensuremath\gtrsim10-100 keV nucleon$^-1$ suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances of <0.1 au from the Sun. Our key findings are as follows: (1) very few heavy ions are detected during the first full crossing, the heavy-ion intensities are reduced during the second partial crossing and peak just after the second crossing; (2) ion arrival times exhibit no velocity dispersion; (3) He pitch-angle distributions track t ... Desai, M.~I.; Mitchell, D.~G.; McComas, D.~J.; Drake, J.~F.; Phan, T.; Szalay, J.~R.; Roelof, E.~C.; Giacalone, J.; Hill, M.~E.; Christian, E.~R.; Schwadron, N.~A.; McNutt, R.~L.; Wiedenbeck, M.~E.; Joyce, C.; Cohen, C.~M.~S.; Davis, A.~J.; Krimigis, S.~M.; Leske, R.~A.; Matthaeus, W.~H.; Malandraki, O.; Mewaldt, R.~A.; Labrador, A.; Stone, E.~C.; Bale, S.~D.; Verniero, J.; Rahmati, A.; Whittlesey, P.; Livi, R.; Larson, D.; Pulupa, M.; MacDowall, R.~J.; Niehof, J.~T.; Kasper, J.~C.; Horbury, T.~S.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4961 Parker Data Used; The Sun; Solar magnetic reconnection; Interplanetary particle acceleration; interplanetary magnetic fields; Heliosphere; 1693; 1504; 826; 824; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Context. Solar Orbiter and Parker Solar Probe jointly observed the solar wind for the first time in June 2020, capturing data from very different solar wind streams: calm, Alfv\ enic wind and also highly dynamic large-scale structures. Context. Our aim is to understand the origin and characteristics of the highly dynamic solar wind observed by the two probes, particularly in the vicinity of the heliospheric current sheet (HCS). \ Methods: We analyzed the plasma data obtained by Parker Solar Probe and Solar Orbiter in situ du ... Réville, V.; Fargette, N.; Rouillard, A.~P.; Lavraud, B.; Velli, M.; Strugarek, A.; Parenti, S.; Brun, A.~S.; Shi, C.; Kouloumvakos, A.; Poirier, N.; Pinto, R.~F.; Louarn, P.; Fedorov, A.; Owen, C.~J.; enot, V.; Horbury, T.~S.; Laker, R.; Brien, H.; Angelini, V.; Fauchon-Jones, E.; Kasper, J.~C.; Published by: \aap Published on: mar YEAR: 2022 DOI: 10.1051/0004-6361/202142381 Parker Data Used; Solar wind; magnetohydrodynamics (MHD); magnetic reconnection; methods: numerical; methods: data analysis; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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The S-shaped magnetic structure in the solar wind formed by the twisting of magnetic field lines is called a switchback, whose main characteristics are the reversal of the magnetic field and the significant increase in the solar wind radial velocity. We identify 242 switchbacks during the first two encounters of Parker Solar Probe. Statistics methods are applied to analyze the distribution and the rotation angle and direction of the magnetic field rotation of the switchbacks. The diameter of switchbacks is estimated with a m ... Meng, Ming-Ming; Liu, Ying; Chen, Chong; Wang, Rui; Published by: Research in Astronomy and Astrophysics Published on: mar YEAR: 2022 DOI: 10.1088/1674-4527/ac49e4 Parker Data Used; ISM: magnetic fields; methods: statistical; (Sun:) solar wind; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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An Extended and Fragmented Alfv\ en Zone in the Young Solar Wind Motivated by theoretical, numerical, and observational evidence, we explore the possibility that the critical transition between sub-Alfv\ enic flow and super-Alfv\ enic flow in the solar atmosphere takes place in fragmented and disconnected subvolumes within a general Alfv\ en critical zone. The initial observations of sub-Alfv\ enic periods by Parker Solar Probe near 16 R$_\ensuremath\odot$ do not yet provide sufficient evidence to distinguish this possibility from that of a folded surface that separates simply-connected r ... Chhiber, Rohit; Matthaeus, William; Usmanov, Arcadi; Bandyopadhyay, Riddhi; Goldstein, Melvyn; Published by: \mnras Published on: mar YEAR: 2022 DOI: 10.1093/mnras/stac779 |
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Categorizing MHD Discontinuities in the Inner Heliosphere by Utilizing the PSP Mission The interplanetary discontinuities (IDs) have been widely observed in astrophysical and space plasmas, while their characteristics and evolutions within 0.3 AU are still unclear due to the limitation of spacecraft orbits in previous missions. Here, we report three ID events, including a rotational discontinuity (RD), a tangential discontinuity (TD), and a suspected contact discontinuity (CD), detected by the Parker Solar Probe in a previously unexplored region of the heliosphere as close to the Sun as 0.13 AU. By the combina ... Liu, Y.~Y.; Fu, H.~S.; Cao, J.~B.; Yu, Y.; Liu, C.~M.; Wang, Z.; Guo, Z.~Z.; He, R.~J.; Published by: Journal of Geophysical Research (Space Physics) Published on: mar YEAR: 2022 DOI: 10.1029/2021JA029983 |
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PSP Observations of a Slow Shock Pair Bounding a Large-Scale Plasmoid/Macro Magnetic Hole Slow shocks are introduced to be the main dissipation sites in Petschek reconnection model, but they are seldom observed in interplanetary space. We report a slow shock pair bounding a plasmoid/macro magnetic hole observed by Parker Solar Probe. The jump conditions across the shocks are examined and confirmed to satisfy the Rankine-Hugoniot relations. The flow speed in the preshock and postshock regions of both shocks match up with the characteristics of slow shocks. The slow shock pair is suggested to be a part of a curved ... Zhou, Zilu; Xu, Xiaojun; Zuo, Pingbing; Wang, Yi; Wang, Ludi; Ye, Yudong; Wang, Ming; Chang, Qing; Wang, Xing; Luo, Lei; Published by: \grl Published on: mar YEAR: 2022 DOI: 10.1029/2021GL097564 Parker Data Used; slow shocks; magnetic reconnection; Solar wind; magnetic hole |
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We propose a transport theory for the kinetic evolution of solar-wind electrons in the heliosphere. We derive a gyro-averaged kinetic transport equation that accounts for the spherical expansion of the solar wind and the geometry of the Parker spiral magnetic field. To solve our three-dimensional kinetic equation, we develop a mathematical approach that combines the Crank-Nicolson scheme in velocity space and a finite-difference Euler scheme in configuration space. We initialize our model with isotropic electron distribution ... Jeong, Seong-Yeop; Verscharen, Daniel; Vocks, Christian; Abraham, Joel; Owen, Christopher; Wicks, Robert; Fazakerley, Andrew; Stansby, David; Ber\vci\vc, Laura; Nicolaou, Georgios; Rueda, Jeffersson; Bakrania, Mayur; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4805 Parker Data Used; Solar wind; Space plasmas; Heliosphere; Theoretical models; 1534; 1544; 711; 2107; Physics - Space Physics |
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eville, Victor; Velli, Marco; Panasenco, Olga; Tenerani, Anna; Shi, Chen; Badman, Samuel; Bale, Stuart; Kasper, J.~C.; Stevens, Michael; Korreck, Kelly; Bonnell, J.~W.; Case, Anthony; de Wit, Thierry; Goetz, Keith; Harvey, Peter; Larson, Davin; Livi, Roberto; Malaspina, David; MacDowall, Robert; Pulupa, Marc; Whittlesey, Phyllis; Published by: \apjs Published on: mar YEAR: 2022 DOI: 10.3847/1538-4365/ac532e |
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The acceleration of charged particles by interplanetary shocks (IPs) can drain a nonnegligible fraction of the plasma pressure. In this study, we have selected 17 IPs observed in situ at 1 au by the Advanced Composition Explorer and the Wind spacecraft, and 1 shock at 0.8 au observed by Parker Solar Probe. We have calculated the time-dependent partial pressure of suprathermal and energetic particles (smaller and greater than 50 keV for protons and 30 keV for electrons, respectively) in both the upstream and downstream region ... David, Liam; Fraschetti, Federico; Giacalone, Joe; Wimmer-Schweingruber, Robert; Berger, Lars; Lario, David; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac54af Parker Data Used; Interplanetary shocks; Interplanetary particle acceleration; Space plasmas; 829; 826; 1544; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics; Physics - Space Physics |
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The solar wind is a highly turbulent plasma for which the mean rate of energy transfer ɛ has been measured for a long time using the Politano-Pouquet (PP98) exact law. However, this law assumes statistical homogeneity that can be violated by the presence of discontinuities. Here, we introduce a new method based on the inertial dissipation $ D _I^{\sigma }$ whose analytical form is derived from incompressible magnetohydrodynamics; it can be considered as a weak and local (in space) formulation of the PP98 law whose expressio ... David, V.; Galtier, S.; Sahraoui, F.; Hadid, L.~Z.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac524b Parker Data Used; interplanetary turbulence; Space plasmas; Solar wind; 830; 1544; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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The transport of energetic charged particles (e.g., cosmic rays) in turbulent magnetic fields is usually characterized in terms of the diffusion parallel and perpendicular to a large-scale (or mean) magnetic field. The nonlinear guiding center theory has been a prominent perpendicular diffusion theory. A recent version of this theory, based on the random ballistic spreading of magnetic field lines and a backtracking correction (RBD/BC), has shown good agreement with test particle simulations for a two-component magnetic turb ... Snodin, A.~P.; Jitsuk, T.; Ruffolo, D.; Matthaeus, W.~H.; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac6e6d Parker Data Used; cosmic rays; magnetic fields; Particle astrophysics; 329; 994; 96; Physics - Plasma Physics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Space Physics |
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Amiri, Mandana; Bandura, Kevin; Boskovic, Anja; Cliche, Jean-Fran\ccois; Deng, Meiling; Dobbs, Matt; Fandino, Mateus; Foreman, Simon; Halpern, Mark; Hill, Alex; Hinshaw, Gary; Höfer, Carolin; Kania, Joseph; Landecker, T.~L.; MacEachern, Joshua; Masui, Kiyoshi; Mena-Parra, Juan; Newburgh, Laura; Ordog, Anna; Pinsonneault-Marotte, Tristan; Polzin, Ava; Reda, Alex; Shaw, Richard; Siegel, Seth; Singh, Saurabh; Vanderlinde, Keith; Wang, Haochen; Willis, James; Wulf, Dallas; Collaboration, CHIME; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac6b9f Parker Data Used; Radio telescopes; Interferometers; Calibration; Quiet Sun; 1360; 805; 2179; 1322; Astrophysics - Instrumentation and Methods for Astrophysics; Astrophysics - Cosmology and Nongalactic Astrophysics |
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The cutoff frequency is an important characteristic parameter of type III radio bursts. Employing the radio data of the Parker Solar Probe (PSP) in the encounter phases of its first five orbits, our previous work revealed that the maximum probability distribution of the cutoff frequency f $_ lo $ (\raisebox-0.5ex\textasciitilde680 kHz) is remarkably higher than that based on Ulysses and WIND (\raisebox-0.5ex\textasciitilde100 kHz) investigated by Leblanc et al. and Dulk et al. However, the main influencing factor of the disc ... Ma, Bing; Chen, Ling; Wu, Dejin; Pulupa, Marc; Bale, Stuart; Published by: \apjl Published on: jun YEAR: 2022 DOI: 10.3847/2041-8213/ac7525 Parker Data Used; Galaxy dynamics; Interplanetary physics; 591; 827 |
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In this Letter, we report observations of magnetic switchback (SB) features near 1 au using data from the Wind spacecraft. These features appear to be strikingly similar to the ones observed by the Parker Solar Probe mission closer to the Sun: namely, one- sided spikes (or enhancements) in the solar-wind bulk speed V that correlate/anticorrelate with the spikes seen in the radial- field component B $_ R $. In the solar-wind streams that we analyzed, these specific SB features near 1 au are associated with large-amplitude Alf ... Bourouaine, Sofiane; Perez, Jean; Raouafi, Nour; Chandran, Benjamin; Bale, Stuart; Velli, Marco; Published by: \apjl Published on: jun YEAR: 2022 DOI: 10.3847/2041-8213/ac67d9 Parker Data Used; Heliosphere; Solar wind; 711; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Visible light observations from the Wide-field Imager for Solar PRobe (WISPR) aboard the Parker Solar Probe (PSP) mission offer a unique opportunity to study the dust environment near the Sun. The existence of a dust-free zone (DFZ) around stars was postulated almost a century ago. Despite numerous attempts to detect it from as close as 0.3 au, observational evidence of a circumsolar DFZ has remained elusive. Analysis of WISPR images obtained from heliocentric distances between 13.3-53.7 R $_\ensuremath\odot$ over multiple P ... Stenborg, Guillermo; Howard, Russell; Vourlidas, Angelos; Gallagher, Brendan; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac6b36 Parker Data Used; Circumstellar dust; Solar F corona; 236; 1991 |
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We numerically integrate the equations of motion of a large number of GeV protons, released impulsively near the Sun, in order to study their time-intensity behavior at the location of an observer at 1 au. This is relevant to the interpretation of Ground Level Enhancements (GLEs) detected by neutron monitors on Earth. Generally, the observed time-intensity profiles reveal a single sharp rise, followed by slow decay. However, in the 1989 October 22 GLE event, there was an initial sharp spike followed by a secondary smaller sp ... Moradi, Ashraf; Giacalone, Joe; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac66e0 Parker Data Used; Solar energetic particles; interplanetary magnetic fields; interplanetary turbulence; solar flares; Solar coronal mass ejections; Solar coronal mass ejection shocks; 1491; 824; 830; 1496; 310; 1997 |
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We develop and apply a bespoke fitting routine to a large volume of solar wind electron distribution data measured by Parker Solar Probe over its first five orbits, covering radial distances from 0.13 to 0.5 au. We characterize the radial evolution of the electron core, halo, and strahl populations in the slow solar wind during these orbits. The fractional densities of these three electron populations provide evidence for the growth of the combined suprathermal halo and strahl populations from 0.13 to 0.17 au. Moreover, the ... Abraham, Joel; Owen, Christopher; Verscharen, Daniel; Bakrania, Mayur; Stansby, David; Wicks, Robert; Nicolaou, Georgios; Whittlesey, Phyllis; Rueda, Jeffersson; Jeong, Seong-Yeop; Ber\vci\vc, Laura; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac6605 Parker Data Used; The Sun; Heliosphere; Plasma physics; Solar wind; 1693; 711; 2089; 1534; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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The Dynamic Structure of Coronal Hole Boundaries The boundaries of solar coronal holes are difficult to uniquely define observationally but are sites of interest in part because the slow solar wind appears to originate there. The aim of this article is to explore the dynamics of interchange magnetic reconnection at different types of coronal hole boundaries- namely streamers and pseudostreamers-and their implications for the coronal structure. We describe synthetic observables derived from three-dimensional magnetohydrodynamic simulations of the atmosphere of the Sun in wh ... Aslanyan, V.; Pontin, D.~I.; Scott, R.~B.; Higginson, A.~K.; Wyper, P.~F.; Antiochos, S.~K.; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac69ed Parker Data Used; Solar Physics; Solar magnetic reconnection; Solar corona; Solar coronal holes; Slow solar wind; Magnetohydrodynamics; 1476; 1504; 1483; 1484; 1873; 1964 |
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Contrasting Scaling Properties of Near-Sun Sub-Alfv\ enic and Super-Alfv\ enic Regions Scale-invariance has rapidly established itself as one of the most used concepts in space plasmas to uncover underlying physical mechanisms via the scaling-law behavior of the statistical properties of field fluctuations. In this work, we characterize the scaling properties of the magnetic field fluctuations in a sub-alfv\ enic region in contrast with those of the nearby super-alfv\ enic zone during the ninth Parker Solar Probe perihelion. With our observations, (i) evidence of an extended self-similarity (ESS) for both the ... Alberti, Tommaso; Benella, Simone; Carbone, Vincenzo; Consolini, Giuseppe; Quattrociocchi, Virgilio; Stumpo, Mirko; Published by: Universe Published on: jun YEAR: 2022 DOI: 10.3390/universe8070338 |
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Constraining Global Coronal Models with Multiple Independent Observables Global coronal models seek to produce an accurate physical representation of the Sun s atmosphere that can be used, for example, to drive space-weather models. Assessing their accuracy is a complex task, and there are multiple observational pathways to provide constraints and tune model parameters. Here, we combine several such independent constraints, defining a model- agnostic framework for standardized comparison. We require models to predict the distribution of coronal holes at the photosphere, and neutral line topology ... Badman, Samuel; Brooks, David; Poirier, Nicolas; Warren, Harry; Petrie, Gordon; Rouillard, Alexis; Arge, Nick; Bale, Stuart; Agüero, Diego; Harra, Louise; Jones, Shaela; Kouloumvakos, Athanasios; Riley, Pete; Panasenco, Olga; Velli, Marco; Wallace, Samantha; Published by: \apj Published on: jun YEAR: 2022 DOI: 10.3847/1538-4357/ac6610 Parker Data Used; Solar Physics; Solar corona; Solar coronal holes; Astronomical models; 1476; 1483; 1484; 86; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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We examine the radial evolution of correlation lengths perpendicular ( $\lambda _C^\perp $ ) and parallel ( $\lambda _C^\parallel $ ) to the magnetic-field direction, computed from solar wind magnetic-field data measured by Parker Solar Probe (PSP) during its first eight orbits, Helios 1, Advanced Composition Explorer (ACE), WIND, and Voyager 1 spacecraft. Correlation lengths are grouped by an interval s alignment angle; the angle between the magnetic-field and solar wind velocity vectors (\ensuremath\Theta$_BV$). Parallel a ... Cuesta, Manuel; Chhiber, Rohit; Roy, Sohom; Goodwill, Joshua; Pecora, Francesco; Jarosik, Jake; Matthaeus, William; Parashar, Tulasi; Bandyopadhyay, Riddhi; Published by: \apjl Published on: jun YEAR: 2022 DOI: 10.3847/2041-8213/ac73fd Parker Data Used; Two-point correlation function; Heliosphere; Solar wind; interplanetary turbulence; 1951; 711; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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An intense solar energetic particle (SEP) event was observed on 2021 October 9 by multiple spacecraft distributed near the ecliptic plane at heliocentric radial distances R \ensuremath\lesssim 1 au and within a narrow range of heliolongitudes. A stream interaction region (SIR), sequentially observed by Parker Solar Probe (PSP) at R = 0.76 au and 48\textdegree east from Earth (\ensuremath\phi = E48\textdegree), STEREO-A (at R = 0.96 au, \ensuremath\phi = E39\textdegree), Solar Orbiter (SolO; at R = 0.68 au, \ensuremath\phi = ... Lario, D.; Wijsen, N.; Kwon, R.~Y.; anchez-Cano, B.; Richardson, I.~G.; Pacheco, D.; Palmerio, E.; Stevens, M.~L.; Szabo, A.; Heyner, D.; Dresing, N.; omez-Herrero, R.; Carcaboso, F.; Aran, A.; Afanasiev, A.; Vainio, R.; Riihonen, E.; Poedts, S.; Brüden, M.; Xu, Z.~G.; Kollhoff, A.; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac6efd Parker Data Used; Corotating streams; Solar energetic particles; Solar coronal mass ejection shocks; 314; 1491; 1997 |
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The solar wind in the inner heliosphere has been observed by Parker Solar Probe (PSP) to exhibit abundant wave activities. The cyclotron wave modes responding to ions or electrons are among the most crucial wave components. However, their origin and evolution in the inner heliosphere close to the Sun remains a mystery. Specifically, it remains unknown whether it is an emitted signal from the solar atmosphere or an eigenmode growing locally in the heliosphere due to plasma instability. To address and resolve this controversy, ... He, Jiansen; Wang, Ying; Zhu, Xingyu; Duan, Die; Verscharen, Daniel; Zhao, Guoqing; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac6c8e Parker Data Used; Solar wind; interplanetary turbulence; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Energetic electrons of Jovian origin have been observed for decades throughout the heliosphere, as far as 11 au, and as close as 0.5 au, from the Sun. The treatment of Jupiter as a continuously emitting point source of energetic electrons has made Jovian electrons a valuable tool in the study of energetic electron transport within the heliosphere. We present observations of Jovian electrons measured by the EPI-Hi instrument in the Integrated Science Investigation of the Sun instrument suite on Parker Solar Probe at distances ... Mitchell, J.~G.; Leske, R.~A.; De Nolfo, G.~A.; Christian, E.~R.; Wiedenbeck, M.~E.; McComas, D.~J.; Cohen, C.~M.~S.; Cummings, A.~C.; Hill, M.~E.; Labrador, A.~W.; Mays, M.~L.; McNutt, R.~L.; Mewaldt, R.~A.; Mitchell, D.~G.; Odstrcil, D.; Schwadron, N.~A.; Stone, E.~C.; Szalay, J.~R.; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac75ce Parker Data Used; Interplanetary particle acceleration; Solar energetic particles; Corotating streams; interplanetary magnetic fields; Heliosphere; 826; 1491; 314; 824; 711 |
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On the Transmission of Turbulent Structures across the Earth s Bow Shock Collisionless shocks and plasma turbulence are crucial ingredients for a broad range of astrophysical systems. The shock-turbulence interaction, and in particular the transmission of fully developed turbulence across the quasi-perpendicular Earth s bow shock, is here addressed using a combination of spacecraft observations and local numerical simulations. An alignment between the Wind (upstream) and Magnetospheric Multiscale (downstream) spacecraft is used to study the transmission of turbulent structures across the shock, r ... Trotta, Domenico; Pecora, Francesco; Settino, Adriana; Perrone, Denise; Hietala, Heli; Horbury, Timothy; Matthaeus, William; Burgess, David; Servidio, Sergio; Valentini, Francesco; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac7798 Parker Data Used; Shocks; Space plasmas; interplanetary turbulence; 2086; 1544; 830; Physics - Space Physics |
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The Dynamic Evolution of Solar Wind Streams Following Interchange Reconnection Interchange reconnection is thought to play an important role in determining the dynamics and material composition of the slow solar wind that originates from near coronal-hole boundaries. To explore the implications of this process we simulate the dynamic evolution of a solar wind stream along a newly-opened magnetic flux tube. The initial condition is composed of a piecewise continuous dynamic equilibrium in which the regions above and below the reconnection site are extracted from steady-state solutions along open and clo ... Scott, Roger; Bradshaw, Stephen; Linton, Mark; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac7144 Parker Data Used; Solar wind; Solar magnetic reconnection; Solar magnetic fields; Solar corona; Heliosphere; 1534; 1504; 1503; 1483; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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MHD Turbulent Power Anisotropy in the Inner Heliosphere We study anisotropic magnetohydrodynamic (MHD) turbulence in the slow solar wind measured by Parker Solar Probe (PSP) and Solar Orbiter (SolO) during its first orbit from the perspective of variance anisotropy and correlation anisotropy. We use the Belcher \& Davis approach (M1) and a new method (M2) that decomposes a fluctuating vector into parallel and perpendicular fluctuating vectors. M1 and M2 calculate the transverse and parallel turbulence components relative to the mean magnetic field direction. The parallel turbulen ... Adhikari, L.; Zank, G.~P.; Zhao, L.; Telloni, D.; Published by: \apj Published on: jul YEAR: 2022 DOI: 10.3847/1538-4357/ac70cb Parker Data Used; interplanetary turbulence; Slow solar wind; Solar wind; 830; 1873; 1534 |
