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Found 272 entries in the Bibliography.
Showing entries from 1 through 50
2023 |
Interferometric imaging of the type IIIb and U radio bursts observed with LOFAR on 22 August 2017 Context. The Sun is the source of different types of radio bursts that are associated with solar flares, for example. Among the most frequently observed phenomena are type III solar bursts. Their radio images at low frequencies (below 100 MHz) are relatively poorly studied due to the limitations of legacy radio telescopes. \ Aims: We study the general characteristics of types IIIb and U with stria structure solar radio bursts in the frequency range of 20-80 MHz, in particular the source size and evolution in different altitu ... Dabrowski, Bartosz; Miku\la, Katarzyna; Flisek, Pawe\l; Vocks, Christian; Zhang, PeiJin; c, Jasmina; Warmuth, Alexander; Morosan, Diana; n, Adam; Fallows, Richard; Bisi, Mario; Krankowski, Andrzej; Mann, Gottfried; B\laszkiewicz, Leszek; Carley, Eoin; Gallagher, Peter; Zucca, Pietro; Rudawy, Pawe\l; Hajduk, Marcin; Kotulak, Kacper; Sidorowicz, Tomasz; Published by: \aap Published on: jan YEAR: 2023   DOI: 10.1051/0004-6361/202142905 Parker Data Used; Sun: radio radiation; Sun: UV radiation; Sun: activity; methods: observational; Astrophysics - Solar and Stellar Astrophysics |
2022 |
On the utility of flux rope models for CME magnetic structure below 30 R$_\ensuremath\odot$ We present a comprehensive analysis of the three-dimensional magnetic flux rope structure generated during the Lynch et al. (2019, ApJ 880:97) magnetohydrodynamic (MHD) simulation of a global-scale, 360 \textdegree -wide streamer blowout coronal mass ejection (CME) eruption. We create both fixed and moving synthetic spacecraft to generate time series of the MHD variables through different regions of the flux rope CME. Our moving spacecraft trajectories are derived from the spatial coordinates of Parker Solar Probe s past enc ... Lynch, Benjamin; Al-Haddad, Nada; Yu, Wenyuan; Palmerio, Erika; Lugaz, No\; Published by: Advances in Space Research Published on: sep YEAR: 2022   DOI: 10.1016/j.asr.2022.05.004 Parker Data Used; magnetohydrodynamics (MHD); Solar corona; Coronal mass ejection (CME); magnetic flux rope; Parker Solar Probe (PSP); Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Extracting the Heliographic Coordinates of Coronal Rays Using Images from WISPR/Parker Solar Probe The Wide-field Imager for Solar Probe (WISPR) onboard Parker Solar Probe (PSP), observing in white light, has a fixed angular field of view, extending from 13.5$^\ensuremath\circ$ to 108$^\ensuremath\circ$ from the Sun and approximately 50$^\ensuremath\circ$ in the transverse direction. In January 2021, on its seventh orbit, PSP crossed the heliospheric current sheet (HCS) near perihelion at a distance of 20 solar radii. At this time, WISPR observed a broad band of highly variable solar wind and multiple coronal rays. For si ... Liewer, P.~C.; Qiu, J.; Ark, F.; Penteado, P.; Stenborg, G.; Vourlidas, A.; Hall, J.~R.; Riley, P.; Published by: \solphys Published on: sep YEAR: 2022   DOI: 10.1007/s11207-022-02058-6 Parker Data Used; Corona; Coronal streamers; Coronal rays; Astrophysics - Solar and Stellar Astrophysics |
We investigate the source eruption, propagation and expansion characteristics, and heliospheric impacts of the 2020 November 29 coronal mass ejection (CME) and associated shock, using remote sensing and in situ observations from multiple spacecraft. A potential-field source-surface model is employed to examine the coronal magnetic fields surrounding the source region. The CME and associated shock are tracked from the early stage to the outer corona using extreme ultraviolet and white light observations. Forward models are ap ... Chen, Chong; Liu, Ying; Zhu, Bei; Published by: \apj Published on: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac7ff6 Parker Data Used; Interplanetary shocks; Solar wind; Solar coronal mass ejections; 829; 1534; 310; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Observation of a Magnetic Switchback in the Solar Corona Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by the Parker Solar Probe. The switchbacks formation mechanism and sources are still unresolved, although candidate mechanisms include Alfv\ enic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection, and geometrical effects related to the Parker spiral. This Letter presents observations from the Metis coronagraph on board a Solar Orbiter of a single large propagating S-shape ... Telloni, Daniele; Zank, Gary; Stangalini, Marco; Downs, Cooper; Liang, Haoming; Nakanotani, Masaru; Andretta, Vincenzo; Antonucci, Ester; Sorriso-Valvo, Luca; Adhikari, Laxman; Zhao, Lingling; Marino, Raffaele; Susino, Roberto; Grimani, Catia; Fabi, Michele; Amicis, Raffaella; Perrone, Denise; Bruno, Roberto; Carbone, Francesco; Mancuso, Salvatore; Romoli, Marco; Da Deppo, Vania; Fineschi, Silvano; Heinzel, Petr; Moses, John; Naletto, Giampiero; Nicolini, Gianalfredo; Spadaro, Daniele; Teriaca, Luca; Frassati, Federica; Jerse, Giovanna; Landini, Federico; Pancrazzi, Maurizio; Russano, Giuliana; Sasso, Clementina; Biondo, Ruggero; Burtovoi, Aleksandr; Capuano, Giuseppe; Casini, Chiara; Casti, Marta; Chioetto, Paolo; De Leo, Yara; Giarrusso, Marina; Liberatore, Alessandro; Berghmans, David; Auchère, Fr\; Cuadrado, Regina; Chitta, Lakshmi; Harra, Louise; Kraaikamp, Emil; Long, David; Mandal, Sudip; Parenti, Susanna; Pelouze, Gabriel; Peter, Hardi; Rodriguez, Luciano; Schühle, Udo; Schwanitz, Conrad; Smith, Phil; Verbeeck, Cis; Zhukov, Andrei; Published by: \apjl Published on: sep YEAR: 2022   DOI: 10.3847/2041-8213/ac8104 Parker Data Used; Solar corona; Solar magnetic reconnection; Solar magnetic fields; Magnetohydrodynamics; Solar Coronal Waves; Slow solar wind; 1483; 1504; 1503; 1964; 1995; 1873; Astrophysics - Solar and Stellar Astrophysics |
The Radial Evolution of the Solar Wind as Organized by Electron Distribution Parameters We utilize observations from the Parker Solar Probe (PSP) to study the radial evolution of the solar wind in the inner heliosphere. We analyze electron velocity distribution functions observed by the Solar Wind Electrons, Alphas, and Protons suite to estimate the coronal electron temperature and the local electric potential in the solar wind. From the latter value and the local flow speed, we compute the asymptotic solar wind speed. We group the PSP observations by asymptotic speed, and characterize the radial evolution of t ... Halekas, J.~S.; Whittlesey, P.; Larson, D.~E.; Maksimovic, M.; 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: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac85b8 Parker Data Used; Solar wind; Slow solar wind; Fast solar wind; 1534; 1873; 1872; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
The closest perihelion pass of Parker Solar Probe (PSP), so far, occurred between 2021 November 16 and 26 and reached \raisebox-0.5ex\textasciitilde13.29 R $_☉$ from Sun center. This pass resulted in very unique observations of the solar corona by the Wide-field Instrument for Solar PRobe (WISPR). WISPR observed at least 10 coronal mass ejections (CMEs), some of which were so close that the structures appear distorted. All of the CMEs appeared to have a magnetic flux rope (MFR) structure, and most were oriented such that t ... Howard, Russell; Stenborg, Guillermo; Vourlidas, Angelos; Gallagher, Brendan; Linton, Mark; Hess, Phillip; Rich, Nathan; Liewer, Paulett; Published by: \apj Published on: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac7ff5 Parker Data Used; Solar coronal mass ejections; Solar wind; Solar K corona; Solar coronal streamers; 310; 1534; 2042; 1486; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics |
Context. We investigated the plasma and magnetic field characteristics of the upstream regions of interplanetary coronal mass ejections (ICMEs) and their evolution as function of distance to the Sun in the inner heliosphere. Results are related both to the development of interplanetary shocks, sheath regions, and compressed solar wind plasma ahead of the magnetic ejecta (ME). \ Aims: From a sample of 45 ICMEs observed by Helios 1/2 and the Parker Solar Probe, we aim to identify four main density structures; namely shock, she ... Published by: \aap Published on: sep YEAR: 2022   DOI: 10.1051/0004-6361/202243291 Parker Data Used; Sun: coronal mass ejections (CMEs); Sun: heliosphere; solar-terrestrial relations; Solar wind; Sun: activity; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics; Physics - Space Physics |
Observations of the Solar F-Corona from Space Lamy, P.~L.; Gilardy, H.; Llebaria, A.; Published by: ßr Published on: sep YEAR: 2022   DOI: 10.1007/s11214-022-00918-y Parker Data Used; F-corona; Zodiacal light; Interplanetary dust; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics |
Galactic Cosmic-Ray Propagation in the Inner Heliosphere: Improved Force-field Model Li, Jung-Tsung; Beacom, John; Peter, Annika; Published by: \apj Published on: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac8cf3 Parker Data Used; cosmic rays; Galactic cosmic rays; Gamma-ray astronomy; Gamma-ray observatories; Magnetohydrodynamics; Plasma astrophysics; Particle astrophysics; High energy astrophysics; Solar Physics; interplanetary turbulence; 329; 567; 628; 632; 1964; 1261; 96; 739; 1476; 830; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; High Energy Physics - Phenomenology; Physics - Plasma Physics; Physics - Space Physics |
Wave emissions at frequencies near electron gyrofrequency harmonics are observed at small heliocentric distances below about 40 R $_\ensuremath\odot$ and are known to occur in regions with quiescent magnetic fields. We show the close connection of these waves to the large-scale properties of the magnetic field. Near electron gyrofrequency harmonic emissions occur only when the ambient magnetic field points to a narrow range of directions bounded by polar and azimuthal angular ranges in the RTN coordinate system of correspond ... Tigik, Sabrina; Vaivads, Andris; Malaspina, David; Bale, Stuart; Published by: \apj Published on: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac8473 Parker Data Used; Space plasmas; Plasma physics; Solar wind; 1544; 2089; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
Coronal Mass Ejection Deformation at 0.1 au Observed by WISPR Although coronal mass ejections (CMEs) resembling flux ropes generally expand self-similarly, deformations along their fronts have been reported in observations and simulations. We present evidence of one CME becoming deformed after a period of self-similar expansion in the corona. The event was observed by multiple white-light imagers on 2021 January 20-22. The change in shape is evident in observations from the heliospheric imagers from the Wide-Field Imager for Solar Probe Plus (WISPR), which observed this CME for \raiseb ... Braga, Carlos; Vourlidas, Angelos; Liewer, Paulett; Hess, Phillip; Stenborg, Guillermo; Riley, Pete; Published by: \apj Published on: oct YEAR: 2022   DOI: 10.3847/1538-4357/ac90bf Parker Data Used; Solar coronal mass ejections; 310; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Modeling of Joint Parker Solar Probe-Metis/Solar Orbiter Observations We present the first theoretical modeling of joint Parker Solar Probe (PSP)-Metis/Solar Orbiter (SolO) quadrature observations. The combined observations describe the evolution of a slow solar wind plasma parcel from the extended solar corona (3.5-6.3 R $_\ensuremath\odot$) to the very inner heliosphere (23.2 R $_\ensuremath\odot$). The Metis/SolO instrument remotely measures the solar wind speed finding a range from 96 to 201 km s$^-1$, and PSP measures the solar wind plasma in situ, observing a radial speed of 219.34 km s$ ... Adhikari, L.; Zank, G.~P.; Telloni, D.; Zhao, L.; Published by: \apjl Published on: oct YEAR: 2022   DOI: 10.3847/2041-8213/ac91c6 Parker Data Used; The Sun; Solar wind; interplanetary turbulence; 1693; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Badman, Samuel; Carley, Eoin; Ca\~nizares, Luis; Dresing, Nina; Jian, Lan; Lario, David; Gallagher, Peter; Oliveros, Juan; Pulupa, Marc; Bale, Stuart; Published by: \apj Published on: oct YEAR: 2022   DOI: 10.3847/1538-4357/ac90c2 Parker Data Used; Solar coronal radio emission; Active Solar Corona; Solar corona; Heliosphere; Solar energetic particles; 1993; 1988; 1483; 711; 1491; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
A canonical description of a corotating solar wind high-speed stream in terms of velocity profile would indicate three main regions: a stream interface or corotating interaction region characterized by a rapid increase in flow speed and by compressive phenomena that are due to dynamical interaction between the fast wind flow and the slower ambient plasma; a fast wind plateau characterized by weak compressive phenomena and large-amplitude fluctuations with a dominant Alfv\ enic character; and a rarefaction region characterize ... Carnevale, G.; Bruno, R.; Marino, R.; Pietropaolo, E.; Raines, J.~M.; Published by: \aap Published on: may YEAR: 2022   DOI: 10.1051/0004-6361/202040006 turbulence; Sun: magnetic fields; Solar wind; magnetohydrodynamics (MHD); Sun: corona; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
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 $), and scale-dependent kurtosis (SDK), each grouped in ranges of heliocentric distance. The Goddard Space Flight Center Space Physics Data Facility provides magnetic-field measurements for resolutions of 6.8 ms for Parker Solar Probe, 6 s for Helios, and 1.92 s ... Cuesta, Manuel; Parashar, Tulasi; Chhiber, Rohit; Matthaeus, William; Published by: \apjs Published on: mar YEAR: 2022   DOI: 10.3847/1538-4365/ac45fa Parker Data Used; Solar wind; interplanetary magnetic fields; Space plasmas; interplanetary turbulence; Interplanetary physics; 1534; 824; 1544; 830; 827; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
Core Electron Heating by Triggered Ion Acoustic Waves in the Solar Wind Perihelion passes on Parker Solar Probe orbits 6-9 have been studied to show that solar wind core electrons emerged from 15 solar radii with a temperature of 55 \ensuremath\pm 5 eV, independent of the solar wind speed, which varied from 300 to 800 km s$^-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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
Context. Magnetic switchbacks in the solar wind are large deflections of the magnetic field vector, which often reverse their radial component, and are associated with a velocity spike consistent with their Alfv\ enic nature. The Parker Solar Probe (PSP) mission revealed them to be a dominant feature of the near-Sun solar wind. Where and how they are formed remains unclear and subject to discussion. \ Aims: We investigate the orientation of the magnetic field deflections in switchbacks to determine if they are characterized ... Fargette, Na; Lavraud, Benoit; Rouillard, Alexis; eville, Victor; Bale, Stuart; Kasper, Justin; Published by: \aap Published on: jul YEAR: 2022   DOI: 10.1051/0004-6361/202243537 Parker Data Used; Solar wind; Sun: magnetic fields; Sun: corona; Sun: photosphere; methods: data analysis; methods: statistical; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Structure and fluctuations of a slow ICME sheath observed at 0.5 au by the Parker Solar Probe Context. Sheath regions ahead of interplanetary coronal mass ejections (ICMEs) are compressed and turbulent global heliospheric structures. Their global and fine-scale structure are outstanding research problems, and only a few studies have been conducted on this topic closer to the Sun than 1 au. Comprehensive knowledge of the sheath structure and embedded fluctuations and of their evolution in interplanetary space is important for understanding their geoeffectiveness, their role in accelerating charged particles to high en ... Kilpua, E.~K.~J.; Good, S.~W.; Ala-Lahti, M.; Osmane, A.; Pal, S.; Soljento, J.~E.; Zhao, L.~L.; Bale, S.; Published by: \aap Published on: jul YEAR: 2022   DOI: 10.1051/0004-6361/202142191 Parker Data Used; Solar wind; Sun: coronal mass ejections (CMEs); shock waves; turbulence; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
Switchbacks-abrupt reversals of the magnetic field within the solar wind-have been ubiquitously observed by Parker Solar Probe (PSP). Their origin, whether from processes near the solar surface or within the solar wind itself, remains under debate and likely has key implications for solar wind heating and acceleration. Here, using three-dimensional expanding box simulations, we examine the properties of switchbacks arising from the evolution of outwards-propagating Alfv\ en waves in the expanding solar wind in detail. Our go ... Johnston, Zade; Squire, Jonathan; Mallet, Alfred; Meyrand, Romain; Published by: Physics of Plasmas Published on: jul YEAR: 2022   DOI: 10.1063/5.0097983 Parker Data Used; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
Density and Velocity Fluctuations of Alpha Particles in Magnetic Switchbacks McManus, Michael; Verniero, Jaye; Bale, Stuart; Bowen, Trevor; Larson, Davin; Kasper, Justin; Livi, Roberto; Matteini, Lorenzo; Rahmati, Ali; Romeo, Orlando; Whittlesey, Phyllis; Woolley, Thomas; Published by: \apj Published on: jul YEAR: 2022   DOI: 10.3847/1538-4357/ac6ba3 Parker Data Used; Heliosphere; Solar wind; Space plasmas; 711; 1534; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
Taylor Microscale and Effective Reynolds Number near the Sun from PSP The Taylor microscale is a fundamental length scale in turbulent fluids, representing the end of fluid properties and onset of dissipative processes. The Taylor microscale can also be used to evaluate the Reynolds number in classical turbulence theory. Although the solar wind is weakly collisional, it approximately behaves as a magnetohydrodynamic (MHD) fluid at scales larger than the kinetic scale. As a result, classical fluid turbulence theory and formalisms are often used to study turbulence in the MHD range. Therefore, a ... Phillips, C.; Bandyopadhyay, R.; McComas, D.~J.; Published by: \apj Published on: jul YEAR: 2022   DOI: 10.3847/1538-4357/ac713f Parker Data Used; Solar wind; interplanetary turbulence; Magnetohydrodynamics; Space plasmas; 1534; 830; 1964; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Quasi-periodic Energy Release and Jets at the Base of Solar Coronal Plumes Coronal plumes are long, ray-like, open structures that have been considered as possible sources of the solar wind. Their origin in the largely unipolar coronal holes has long been a mystery. Earlier spectroscopic and imaging observations revealed blueshifted plasma and propagating disturbances (PDs) in plumes that are widely interpreted in terms of flows and/or propagating slow-mode waves, but these interpretations (flows versus waves) remain under debate. Recently we discovered an important clue about plume internal struct ... Kumar, Pankaj; Karpen, Judith; Uritsky, Vadim; Deforest, Craig; Raouafi, Nour; DeVore, Richard; Published by: \apj Published on: jul YEAR: 2022   DOI: 10.3847/1538-4357/ac6c24 Parker Data Used; Jets; Solar magnetic reconnection; Solar wind; Solar coronal plumes; 870; 1504; 1534; 2039; Astrophysics - Solar and Stellar Astrophysics |
Parker Solar Probe detects solar radio bursts related with a behind-the-limb active region Context. The interpretation of solar radio bursts observed by Parker Solar Probe (PSP) in the encounter phase plays a key role in understanding intrinsic properties of the emission mechanism in the solar corona. Lower time-frequency resolution of the PSP receiver can be overcome by simultaneous ground-based observations using more advanced antennas and receivers. \ Aims: In this paper we present such observations for which the active active region 12 765, begetter of type III, J, and U solar bursts, was within sight of groun ... Stanislavsky, Aleksander; Bubnov, Igor; Koval, Artem; Yerin, Serge; Published by: \aap Published on: jan YEAR: 2022   DOI: 10.1051/0004-6361/202141984 Parker Data Used; Sun: activity; Sun: corona; Sun: radio radiation; methods: observational; space vehicles; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
We report the result of the first search for multipoint in situ and imaging observations of interplanetary coronal mass ejections (ICMEs) starting with the first Solar Orbiter (SolO) data in 2020 April-2021 April. A data exploration analysis is performed including visualizations of the magnetic-field and plasma observations made by the five spacecraft SolO, BepiColombo, Parker Solar Probe (PSP), Wind, and STEREO-A, in connection with coronagraph and heliospheric imaging observations from STEREO-A/SECCHI and SOHO/LASCO. We id ... Möstl, Christian; Weiss, Andreas; Reiss, Martin; Amerstorfer, Tanja; Bailey, Rachel; Hinterreiter, Jürgen; Bauer, Maike; Barnes, David; Davies, Jackie; Harrison, Richard; von Forstner, Johan; Davies, Emma; Heyner, Daniel; Horbury, Tim; Bale, Stuart; Published by: \apjl Published on: jan YEAR: 2022   DOI: 10.3847/2041-8213/ac42d0 Parker Data Used; 310; 1526; 1534; 1476; 827; 824; 829; 711; 2037; 1472; 1528; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Inertial-range Magnetic-fluctuation Anisotropy Observed from Parker Solar Probe s First Seven Orbits Solar wind turbulence is anisotropic with respect to the mean magnetic field. Anisotropy leads to ambiguity when interpreting in situ turbulence observations in the solar wind because an apparent change in the measurements could be due to either the change of intrinsic turbulence properties or to a simple change of the spacecraft sampling direction. We demonstrate the ambiguity using the spectral index and magnetic compressibility in the inertial range observed by the Parker Solar Probe during its first seven orbits ranging ... Zhao, L.; Zank, G.~P.; Adhikari, L.; Nakanotani, M.; Published by: \apjl Published on: jan YEAR: 2022   DOI: 10.3847/2041-8213/ac4415 Parker Data Used; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
We propose a model for interpreting highly variable ion composition ratios in solar energetic particle (SEP) events recently observed by the Parker Solar Probe (PSP) at 0.3-0.45 au. We use numerical simulations to calculate SEP propagation in a turbulent interplanetary magnetic field with a Kolmogorov power spectrum from large scales down to the gyration scale of energetic particles. We show that when the source regions of different species are offset by a distance comparable to the size of the source regions, the observed e ... Guo, Fan; Zhao, Lulu; Cohen, Christina; Giacalone, Joe; Leske, R.~A.; Wiedenbeck, M.~E.; Kahler, S.~W.; Li, Xiaocan; Zhang, Qile; Ho, George; Desai, Mihir; Published by: \apj Published on: jan YEAR: 2022   DOI: 10.3847/1538-4357/ac3233 Parker Data Used; 1491; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
Suprathermal ions in the corona are thought to serve as seed particles for large gradual solar energetic particle (SEP) events associated with fast and wide coronal mass ejections (CMEs). A better understanding of the role of suprathermal particles as seed populations for SEP events can be made by using observations close to the Sun. We study a series of SEP events observed by the Integrated Science Investigation of the Sun (IS\ensuremath\odotIS) suite on board the Parker Solar Probe (PSP) from 2020 May 27 to June 2, during ... Zhuang, Bin; Lugaz, No\; Lario, David; Published by: \apj Published on: jan YEAR: 2022   DOI: 10.3847/1538-4357/ac3af2 Parker Data Used; 1491; 310; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Anomalous Cosmic-Ray Oxygen Observations into 0.1 au The Integrated Science Investigation of the Sun instrument suite onboard NASA s Parker Solar Probe mission continues to measure solar energetic particles and cosmic rays closer to the Sun than ever before. Here, we present the first observations of cosmic rays into 0.1 au (21.5 solar radii), focusing specifically on oxygen from \raisebox-0.5ex\textasciitilde2018.7 to \raisebox-0.5ex\textasciitilde2021.2. Our energy spectra reveal an anomalous cosmic-ray-dominated profile that is comparable to that at 1 au, across multiple so ... Rankin, J.~S.; McComas, D.~J.; Leske, R.~A.; Christian, E.~R.; Cohen, C.~M.~S.; Cummings, A.~C.; Joyce, C.~J.; Labrador, A.~W.; Mewaldt, R.~A.; Schwadron, N.~A.; Stone, E.~C.; Strauss, R.~D.; Wiedenbeck, M.~E.; Published by: \apj Published on: jan YEAR: 2022   DOI: 10.3847/1538-4357/ac348f Parker Data Used; 567; 329; 1487; 1193; 1503; 1476; 1534; 96; 1544; 711; 1322; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |