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Found 24 entries in the Bibliography.
Showing entries from 1 through 24
2023 |
We investigate the generation and evolution of switchbacks (SBs), the nature of the sub-Alfv\ enic wind observed by the Parker Solar Probe (PSP), and the morphology of the Alfv\ enic transition, all of which are key issues in solar wind research. First we highlight a special structure in the pristine solar wind, termed a low Mach-number boundary layer (LMBL). An increased Alfv\ en radius and suppressed SBs are observed within an LMBL. A probable source on the Sun for an LMBL is the peripheral region inside a coronal hole wit ... Liu, Ying; Ran, Hao; Hu, Huidong; Bale, Stuart; Published by: \apj Published on: feb YEAR: 2023   DOI: 10.3847/1538-4357/acb345 Parker Data Used; Solar wind; Solar magnetic fields; interplanetary turbulence; Solar Coronal Waves; Solar coronal holes; 1534; 1503; 830; 1995; 1484; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
2022 |
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 |
Switchbacks are localized deviations from the nominal Parker spiral field in the solar wind. In this study, we investigate the electron distributions inside switchbacks, focusing primarily on the suprathermal (halo and strahl) populations. We explore electron parameters in relation to the angle of rotation of the magnetic field from radial to determine whether electron distributions observed within switchbacks have any differences from those outside of switchbacks. Our observations reveal several trends in the suprathermal e ... Nair, Raaman; Halekas, Jasper; Whittlesey, Phyllis; Larson, Davin; Livi, Roberto; Berthomier, Matthieu; Kasper, Justin; Case, Anthony; Stevens, Michael; Bale, Stuart; MacDowall, Robert; Pulupa, Marc; Published by: \apj Published on: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac88c4 Parker Data Used; Solar wind; Space plasmas; Solar corona; Solar magnetic fields; Solar Physics; 1534; 1544; 1483; 1503; 1476 |
Inhomogeneous Kinetic Alfv\ en Waves in the Near-Sun Solar Wind Intervals of intense electromagnetic, broadband plasma waves are reported in the near-Sun solar wind. These waves are identified as kinetic Alfv\ en waves (KAWs), based on comparison between data and theory for their observed electric- to magnetic-field ratio, and magnetic compressibility, as a function of frequency. In contrast to KAW observations at 1 au, KAWs in the near-Sun solar wind are found to be spatially inhomogeneous, preferentially occurring where the ambient magnetic field experiences strong deviations from the ... Malaspina, David; Chasapis, Alexandros; Tatum, Peter; Salem, Chadi; Bale, Stuart; Bonnell, John; de Wit, Thierry; Goetz, Keith; Pulupa, Marc; Halekas, Jasper; Whittlesey, Phyllis; Livi, Roberto; Case, Anthony; Stevens, Michael; Larson, Davin; Published by: \apj Published on: sep YEAR: 2022   DOI: 10.3847/1538-4357/ac87a7 Parker Data Used; Solar wind; Alfven waves; interplanetary turbulence; Space plasmas; Solar magnetic fields; 1534; 23; 830; 1544; 1503 |
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 |
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 |
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 |
We report small-scale magnetic flux ropes via the in situ measurements from the Parker Solar Probe during the first six encounters, and present additional analyses to supplement our prior work in Chen et al. These flux ropes are detected by the Grad-Shafranov-based algorithm, with their durations and scale sizes ranging from 10 s to \ensuremath\lesssim1 hr and from a few hundred kilometers to 10$^-3$ au, respectively. They include both static structures and those with significant field-aligned plasma flows. Most structures t ... Published by: \apj Published on: jan YEAR: 2022   DOI: 10.3847/1538-4357/ac3487 Parker Data Used; 1858; 830; 1504; 1503; 1534; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
The Imprint of Intermittent Interchange Reconnection on the Solar Wind The solar wind is known to be highly structured in space and time. Observations from Parker Solar Probe have revealed an abundance of so-called magnetic switchbacks within the near-Sun solar wind. In this Letter, we use a high-resolution, adaptive-mesh, magnetohydrodynamics simulation to explore the disturbances launched into the solar wind by intermittent/bursty interchange reconnection and how they may be related to magnetic switchbacks. We find that repeated ejection of plasmoid flux ropes into the solar wind produces a c ... Wyper, Peter; DeVore, C.~R.; Antiochos, S.~K.; Pontin, D.~I.; Higginson, Aleida; Scott, Roger; Masson, Sophie; Pelegrin-Frachon, Theo; Published by: \apjl Published on: dec YEAR: 2022   DOI: 10.3847/2041-8213/aca8ae Parker Data Used; Solar corona; Solar coronal holes; Solar wind; Solar magnetic reconnection; Solar magnetic fields; Solar Physics; 1483; 1484; 1534; 1504; 1503; 1476 |
Solar Chromospheric Network as a Source for Solar Wind Switchbacks Recent studies suggest that the magnetic switchbacks (SBs) detected by the Parker Solar Probe carry information on the scales of solar supergranulation (large scale) and granulation (medium scale). We test this claim using high-resolution H\ensuremath\alpha images obtained with the visible spectropolarimeters of the Goode Solar Telescope in Big Bear Solar Observatory. As possible solar sources, we count all the spicule-like features standing along the chromospheric networks near the coronal hole boundary visible in the H\ens ... Lee, Jeongwoo; Yurchyshyn, Vasyl; Wang, Haimin; Yang, Xu; Cao, Wenda; Oliveros, Juan; Published by: \apjl Published on: aug YEAR: 2022   DOI: 10.3847/2041-8213/ac86bf Parker Data Used; Solar magnetic fields; Solar chromosphere; Solar wind; interplanetary magnetic fields; 1503; 1479; 1534; 824 |
The first solar encounters by the Parker Solar Probe revealed the magnetic field to be dominated by short field reversals in the radial direction, referred to as switchbacks. While radial velocity and proton temperature were shown to increase inside the switchbacks, \ensuremath\midB\ensuremath\mid exhibits very brief dropouts only at the switchback boundaries. Brief intensifications in spectral density measurements near the electron plasma frequency, f $_pe$, were also observed at these boundaries, indicating the presenc ... Rasca, Anthony; Farrell, William; Whittlesey, Phyllis; MacDowall, Robert; Bale, Stuart; Kasper, Justin; Published by: \apj Published on: aug YEAR: 2022   DOI: 10.3847/1538-4357/ac80c3 Parker Data Used; Solar magnetic fields; Plasma physics; Solar wind; 1503; 2089; 1534 |
New Insights into the First Two PSP Solar Encounters Enabled by Modeling Analysis with ADAPT-WSA Parker Solar Probe s (PSP s) unique orbital path allows us to observe the solar wind closer to the Sun than ever before. Essential to advancing our knowledge of solar wind and energetic particle formation is identifying the sources of PSP observations. We report on results for the first two PSP solar encounters derived using the Wang-Sheeley-Arge (WSA) model driven by Air Force Data Assimilative Photospheric Flux Transport (ADAPT) model maps. We derive the coronal magnetic field and the 1 R $_\ensuremath\odot$ source regions ... Wallace, Samantha; Jones, Shaela; Arge, Nick; Viall, Nicholeen; Henney, Carl; Published by: \apj Published on: aug YEAR: 2022   DOI: 10.3847/1538-4357/ac731c Parker Data Used; Solar wind; Solar magnetic fields; Solar corona; 1534; 1503; 1483; Astrophysics - Solar and Stellar Astrophysics |
2021 |
Parker Solar Probe (PSP) data recorded within a heliocentric radial distance of 0.3 au have revealed a magnetic field dominated by Alfv\ enic structures that undergo large local variations or even reversals of the radial magnetic field. They are called magnetic switchbacks, they are consistent with folds in magnetic field lines within a same magnetic sector and are associated with velocity spikes during an otherwise calmer background. They are thought to originate either in the low solar atmosphere through magnetic reconnect ... Fargette, Na; Lavraud, Benoit; Rouillard, Alexis; eville, Victor; de Wit, Thierry; Froment, Clara; Halekas, Jasper; Phan, Tai; Malaspina, David; Bale, Stuart; Kasper, Justin; Louarn, Philippe; Case, Anthony; Korreck, Kelly; Larson, Davin; Pulupa, Marc; Stevens, Michael; Whittlesey, Phyllis; Berthomier, Matthieu; Published by: \apj Published on: oct YEAR: 2021   DOI: 10.3847/1538-4357/ac1112 Solar wind; Solar Physics; Wavelet analysis; Supergranulation; Solar granulation; Solar magnetic fields; 1534; 1476; 1918; 1662; 1498; 1503; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used |
Macro magnetic holes (MMHs), which are significant magnetic field decreases in the solar wind lasting tens of minutes, were found during the first four orbits of the Parker Solar Probe (PSP). We performed a detailed analysis of the 2020 January 30 event and found the possible cause of the MMH using coordinated remote sensing observations from STEREO A and PSP in situ measurements. The results indicate that an MMH represents a brief encounter with the rippled heliospheric current sheet (HCS). Out of the data from the first fo ... Chen, Chong; Liu, Ying; Hu, Huidong; Published by: \apj Published on: nov YEAR: 2021   DOI: 10.3847/1538-4357/ac1b2b Parker Data Used; Solar wind; Heliosphere; Solar magnetic fields; 1534; 711; 1503 |
Computer-assisted tomography (CAT) for interplanetary scintillation (IPS) observations enables the determination of the global distribution of solar wind speed. We compared solar wind speeds derived from the CAT analysis of IPS observations between 1985 and 2019 with in situ observations conducted by the near-Earth and Ulysses spacecraft. From this comparison, we found that solar wind speeds from the IPS observations for 2009-2019 were systematically higher than the in situ observations, whereas those for the period until 20 ... Tokumaru, Munetoshi; Fujiki, Ken; Kojima, Masayoshi; Iwai, Kazumasa; Published by: \apj Published on: nov YEAR: 2021   DOI: 10.3847/1538-4357/ac1862 Parker Data Used; 1503; 1534; 828; 1487 |
Small-scale Magnetic Flux Ropes with Field-aligned Flows via the PSP In Situ Observations Magnetic flux rope, formed by the helical magnetic field lines, can sometimes maintain its shape while carrying significant plasma flow that is aligned with the local magnetic field. We report the existence of such structures and static flux ropes by applying the Grad-Shafranov-based algorithm to the Parker Solar Probe in situ measurements in the first five encounters. These structures are detected at heliocentric distances, ranging from 0.13 to 0.66 au, in a 4-month time period. We find that flux ropes with field-aligned fl ... Chen, Yu; Hu, Qiang; Zhao, Lingling; Kasper, Justin; Huang, Jia; Published by: \apj Published on: jun YEAR: 2021   DOI: 10.3847/1538-4357/abfd30 Parker Data Used; Solar wind; Astronomy data analysis; interplanetary turbulence; Solar magnetic reconnection; Solar magnetic fields; 1534; 1858; 830; 1504; 1503; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Switchback Boundary Dissipation and Relative Age We examine Parker Solar Probe (PSP) magnetic field and plasma observations during its first encounter with the Sun in early 2018 November. During this perihelion time, impulsive reversals in the magnetic field, called switchbacks, were found in the data set characterized by a quick rotation in B along with a simultaneous increase in solar wind flow. In this work, we examine the structure and morphology of 920 switchback boundaries as PSP enters and exits the structures, specifically looking for evidence of boundary degra ... Farrell, W.~M.; Rasca, A.~P.; MacDowall, R.~J.; Gruesbeck, J.~R.; Bale, S.~D.; Kasper, J.~C.; Published by: \apj Published on: jul YEAR: 2021   DOI: 10.3847/1538-4357/ac005b Parker Data Used; Solar wind; Solar Physics; Solar magnetic flux emergence; Solar magnetic fields; 1534; 1476; 2000; 1503 |
Assessing the Role of Interchange Reconnection in Forming Switchbacks Abrupt deflections of the magnetic field in the solar wind, so called switchbacks, are frequently observed by the Parker Solar Probe (PSP) during its first two orbits and are believed to play an important role in unveiling the nature of solar corona heating and solar wind acceleration in the inner heliosphere. Many attempts were made recently to understand the nature of switchbacks. However, the origin, propagation, and evolution of switchbacks are still under debate. In this study, we attempt to use the linear theory of ... Liang, H.; Zank, G.~P.; Nakanotani, M.; Zhao, L.; Published by: \apj Published on: aug YEAR: 2021   DOI: 10.3847/1538-4357/ac0a73 Space plasmas; Solar wind; Solar magnetic fields; Parker Data Used; Solar magnetic reconnection; 1544; 1534; 1503; 1504 |
The random advection of passive additives in a turbulent fluid plays an important role in solar physics, astrophysics, and atmospheric sciences. We concern ourselves here with the case where the fluctuations are not statistically homogeneous in space, and, hence, where the transport coefficients vary with position. Using a numerical model in which the fluid turbulence is defined kinematically, we show that the evolution of the distribution of passive tracers in the fluid is not always governed by the ordinary diffusion equat ... Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021   DOI: 10.3847/1538-4357/abf0b2 Plasma astrophysics; Solar magnetic fields; hydrodynamics; Astrophysical fluid dynamics; Atmospheric science; 1261; 1503; 1963; 101; 116; Parker Data Used |
Switchbacks Explained: Super-Parker Fields—The Other Side of the Sub-Parker Spiral We provide a simple geometric explanation for the source of switchbacks and associated large and one-sided transverse flows in the solar wind observed by the Parker Solar Probe (PSP). The more radial, sub-Parker spiral structure of the heliospheric magnetic field observed previously by Ulysses, ACE, and STEREO is created within rarefaction regions where footpoint motion from the source of fast into slow wind at the Sun creates a magnetic fieldline connection across solar wind speed shear. Conversely, when footpoints move fro ... Published by: The Astrophysical Journal Published on: 03/2021 YEAR: 2021   DOI: 10.3847/1538-4357/abd4e6 Parker Data Used; Active Solar Corona; Solar wind; Solar Coronal Waves; Solar coronal loops; Solar coronal holes; Solar coronal plumes; Solar magnetic fields; interplanetary magnetic fields; Solar spicules; 1988; 1534; 1995; 1485; 1484; 2039; 1503; 824; 1525; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; 85 |
Characteristics of Magnetic Holes in the Solar Wind Revealed by Parker Solar Probe Yu, L.; Huang, S.~Y.; Yuan, Z.~G.; Jiang, K.; Xiong, Q.~Y.; Xu, S.~B.; Wei, Y.~Y.; Zhang, J.; Zhang, Z.~H.; Published by: \apj Published on: 02/2021 YEAR: 2021   DOI: 10.3847/1538-4357/abb9a8 Solar wind; Solar Physics; interplanetary magnetic fields; Solar magnetic fields; 1534; 1476; 824; 1503; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
2020 |
Investigating the Chromospheric Footpoints of the Solar Wind Bryans, Paul; McIntosh, Scott; Brooks, David; De Pontieu, Bart; Published by: \apjl Published on: 12/2021 YEAR: 2020   DOI: 10.3847/2041-8213/abce69 Quiet solar chromosphere; Solar magnetic fields; Solar coronal holes; Solar corona; 1986; 1503; 1484; 1483 |
A Model for Coronal Inflows and In/Out Pairs Published by: \apj Published on: 12/2020 YEAR: 2020   DOI: 10.3847/1538-4357/abc5b3 Active Solar Corona; Solar coronal streamers; Solar coronal transients; Solar magnetic fields; Solar magnetic reconnection; Magnetohydrodynamics; 1988; 1486; 312; 1503; 1504; 1964; Astrophysics - Solar and Stellar Astrophysics |
Coronal-jet-producing Minifilament Eruptions as a Possible Source of Parker Solar Probe Switchbacks The Parker Solar Probe (PSP) has observed copious rapid magnetic field direction changes in the near-Sun solar wind. These features have been called "switchbacks," and their origin is a mystery. But their widespread nature suggests that they may be generated by a frequently occurring process in the Sun\textquoterights atmosphere. We examine the possibility that the switchbacks originate from coronal jets. Recent work suggests that many coronal jets result when photospheric magnetic flux cancels, and forms a small-scale "m ... Sterling, Alphonse; Moore, Ronald; Published by: The Astrophysical Journal Published on: 06/2020 YEAR: 2020   DOI: 10.3847/2041-8213/ab96be 1503; 1504; 1534; 1981; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
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