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Found 306 entries in the Bibliography.
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2023 |
Magnetic Reconnection as the Driver of the Solar Wind We present EUV solar observations showing evidence for omnipresent jetting activity driven by small-scale magnetic reconnection at the base of the solar corona. We argue that the physical mechanism that heats and drives the solar wind at its source is ubiquitous magnetic reconnection in the form of small-scale jetting activity (a.k.a. jetlets). This jetting activity, like the solar wind and the heating of the coronal plasma, is ubiquitous regardless of the solar cycle phase. Each event arises from small-scale reconnection of ... Raouafi, Nour; Stenborg, G.; Seaton, D.~B.; Wang, H.; Wang, J.; DeForest, C.~E.; Bale, S.~D.; Drake, J.~F.; Uritsky, V.~M.; Karpen, J.~T.; DeVore, C.~R.; Sterling, A.~C.; Horbury, T.~S.; Harra, L.~K.; Bourouaine, S.; Kasper, J.~C.; Kumar, P.; Phan, T.~D.; Velli, M.; Published by: \apj Published on: mar YEAR: 2023   DOI: 10.3847/1538-4357/acaf6c Parker Data Used; Solar corona; Solar wind; magnetic fields; Solar magnetic reconnection; 1483; 1534; 994; 1504; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Spacecraft radial alignments for investigations of the evolution of solar wind turbulence: A review With the launch of the Parker Solar Probe, BepiColombo, and Solar Orbiter missions in the three-year period 2018 - 2020 , the investigation of the evolution of solar wind turbulence, dynamics, and structures in the inner heliosphere has become more readily feasible, thanks to the increasing availability of orbital configurations suitable for multi-point observations of the Sun and the processes it drives in interplanetary space. Specifically, data analysis, models, and numerical simulations based on multi-spacecraft coordina ... Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: jan YEAR: 2023   DOI: 10.1016/j.jastp.2022.105999 Parker Data Used; magnetohydrodynamics (MHD); plasmas; turbulence; space vehicles; Sun: heliosphere; Solar wind |
Magnetic Field Spectral Evolution in the Inner Heliosphere Parker Solar Probe and Solar Orbiter data are used to investigate the radial evolution of magnetic turbulence between 0.06 \ensuremath\lesssim R \ensuremath\lesssim 1 au. The spectrum is studied as a function of scale, normalized to the ion inertial scale d $_ i $. In the vicinity of the Sun, the inertial range is limited to a narrow range of scales and exhibits a power-law exponent of, \ensuremath\alpha $_ B $ = -3/2, independent of plasma parameters. The inertial range grows with distance, progressively extending to larger ... Sioulas, Nikos; Huang, Zesen; Shi, Chen; Velli, Marco; Tenerani, Anna; Bowen, Trevor; Bale, Stuart; Huang, Jia; Vlahos, Loukas; Woodham, L.~D.; Horbury, T.~S.; de Wit, Thierry; Larson, Davin; Kasper, Justin; Owen, Christopher; Stevens, Michael; Case, Anthony; Pulupa, Marc; Malaspina, David; Bonnell, J.~W.; Livi, Roberto; Goetz, Keith; Harvey, Peter; MacDowall, Robert; c, Milan; Louarn, P.; Fedorov, A.; Published by: \apjl Published on: jan YEAR: 2023   DOI: 10.3847/2041-8213/acaeff Parker Data Used; Solar wind; Magnetohydrodynamics; interplanetary turbulence; Space plasmas; Plasma astrophysics; 1534; 1964; 830; 1544; 1261; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
In this study we examine the radial dependence of the inertial and dissipation range indices, as well as the spectral break separating the inertial and dissipation range in power density spectra of interplanetary magnetic field fluctuations using Parker Solar Probe data from the fifth solar encounter between \raisebox-0.5ex\textasciitilde0.1 and \raisebox-0.5ex\textasciitilde0.7 au. The derived break wavenumber compares reasonably well with previous estimates at larger radial distances and is consistent with gyro-resonant da ... Lotz, S.; Nel, A.~E.; Wicks, R.~T.; Roberts, O.~W.; Engelbrecht, N.~E.; Strauss, R.~D.; Botha, G.~J.~J.; Kontar, E.~P.; Pit\vna, A.; Bale, S.~D.; Published by: \apj Published on: jan YEAR: 2023   DOI: 10.3847/1538-4357/aca903 Parker Data Used; Space plasmas; Solar wind; interplanetary turbulence; 1544; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Using in situ measurements from the Parker Solar Probe and Wind spacecraft, we investigate the small-scale magnetic flux ropes (SFRs) and their properties inside stream interaction regions (SIRs). Within SIRs from \raisebox-0.5ex\textasciitilde0.15 to 1 au, SFRs are found to exist in a wide range of solar wind speeds with more frequent occurrences after the stream interface, and the Alfv\ enicity of these structures decreases significantly with increasing heliocentric distances. Furthermore, we examine the variation of five ... Chen, Yu; Hu, Qiang; Allen, Robert; Jian, Lan; Published by: \apj Published on: jan YEAR: 2023   DOI: 10.3847/1538-4357/aca894 Parker Data Used; Solar wind; Fast solar wind; Astronomy data analysis; Solar magnetic reconnection; 1534; 1872; 1858; 1504 |
Transport of Cosmic-Ray Electrons from 1 au to the Sun Gamma rays are produced by cosmic-ray (CR) protons interacting with the particles at the solar photosphere and by CR electrons and positrons (CRes) via inverse Compton scattering of solar photons. The former comes from the solar disk while the latter extends beyond the disk. Evaluation of these emissions requires the flux and spectrum of CRs in the vicinity of the Sun, while most observations provide flux and spectra near the Earth, at around 1 au from the Sun. Past estimates of the quiet Sun gamma- ray emission use phenomen ... Petrosian, Vah\; Orlando, Elena; Strong, Andrew; Published by: \apj Published on: jan YEAR: 2023   DOI: 10.3847/1538-4357/aca474 Parker Data Used; cosmic rays; Solar wind; interplanetary turbulence; 329; 1534; 830; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Solar and Stellar Astrophysics |
Parker Solar Probe: Four Years of Discoveries at Solar Cycle Minimum Launched on 12 Aug. 2018, NASA s Parker Solar Probe had completed 13 of its scheduled 24 orbits around the Sun by Nov. 2022. The mission s primary science goal is to determine the structure and dynamics of the Sun s coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what processes accelerate energetic particles. Parker Solar Probe returned a treasure trove of science data that far exceeded quality, significance, and quantity expectations, leading to a significant number ... Raouafi, N.~E.; Matteini, L.; Squire, J.; Badman, S.~T.; Velli, M.; Klein, K.~G.; Chen, C.~H.~K.; Matthaeus, W.~H.; Szabo, A.; Linton, M.; Allen, R.~C.; Szalay, J.~R.; Bruno, R.; Decker, R.~B.; Akhavan-Tafti, M.; Agapitov, O.~V.; Bale, S.~D.; Bandyopadhyay, R.; Battams, K.; Ber\vci\vc, L.; Bourouaine, S.; Bowen, T.~A.; Cattell, C.; Chandran, B.~D.~G.; Chhiber, R.; Cohen, C.~M.~S.; Amicis, R.; Giacalone, J.; Hess, P.; Howard, R.~A.; Horbury, T.~S.; Jagarlamudi, V.~K.; Joyce, C.~J.; Kasper, J.~C.; Kinnison, J.; Laker, R.; Liewer, P.; Malaspina, D.~M.; Mann, I.; McComas, D.~J.; Niembro-Hernandez, T.; Nieves-Chinchilla, T.; Panasenco, O.; y, Pokorn\; Pusack, A.; Pulupa, M.; Perez, J.~C.; Riley, P.; Rouillard, A.~P.; Shi, C.; Stenborg, G.; Tenerani, A.; Verniero, J.~L.; Viall, N.; Vourlidas, A.; Wood, B.~E.; Woodham, L.~D.; Woolley, T.; Published by: ßr Published on: feb YEAR: 2023   DOI: 10.1007/s11214-023-00952-4 Parker Data Used; Sun; Corona; Solar wind; plasma; magnetic fields; coronal mass ejections; parker solar probe; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
Association of intermittency with electron heating in the near-Sun solar wind Several studies in the near-Earth environment show that intermittent structures are important sites of energy dissipation and particle energization. Recent Parker Solar Probe (PSP) data, sampled in the near-Sun environment, have shown that proton heating is concentrated near coherent structures, suggesting local heating of protons by turbulent cascade in this region. However, whether electrons exhibit similar behaviour in the near-Sun environment is not clear. Here, we address this question using PSP data collected near the ... Phillips, C.; Bandyopadhyay, R.; McComas, D.~J.; Bale, S.~D.; Published by: \mnras Published on: feb YEAR: 2023   DOI: 10.1093/mnrasl/slac143 Parker Data Used; (magnetohydrodynamics) MHD; turbulence; Sun: corona; Solar wind; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
Does Turbulence along the Coronal Current Sheet Drive Ion Cyclotron Waves? Evidence for the presence of ion cyclotron waves (ICWs), driven by turbulence, at the boundaries of the current sheet is reported in this paper. By exploiting the full potential of the joint observations performed by Parker Solar Probe and the Metis coronagraph on board Solar Orbiter, local measurements of the solar wind can be linked with the large-scale structures of the solar corona. The results suggest that the dynamics of the current sheet layers generates turbulence, which in turn creates a sufficiently strong temperat ... Telloni, Daniele; Zank, Gary; Adhikari, Laxman; Zhao, Lingling; Susino, Roberto; Antonucci, Ester; Fineschi, Silvano; Stangalini, Marco; Grimani, Catia; Sorriso-Valvo, Luca; Verscharen, Daniel; Marino, Raffaele; Giordano, Silvio; Amicis, Raffaella; Perrone, Denise; Carbone, Francesco; Liberatore, Alessandro; Bruno, Roberto; Zimbardo, Gaetano; Romoli, Marco; Andretta, Vincenzo; Da Deppo, Vania; Heinzel, Petr; Moses, John; Naletto, Giampiero; Nicolini, Gianalfredo; Spadaro, Daniele; Teriaca, Luca; Burtovoi, Aleksandr; De Leo, Yara; Jerse, Giovanna; Landini, Federico; Pancrazzi, Maurizio; Sasso, Clementina; Slemer, Alessandra; Published by: \apj Published on: feb YEAR: 2023   DOI: 10.3847/1538-4357/acb693 Parker Data Used; Magnetohydrodynamics; interplanetary turbulence; Alfven waves; Solar corona; Solar coronal heating; Coronagraphic imaging; Solar wind; Heliosphere; Space plasmas; 1964; 830; 23; 1483; 1989; 313; 1534; 711; 1544; Astrophysics - Solar and Stellar Astrophysics |
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 |
Proton and Electron Temperatures in the Solar Wind and Their Correlations with the Solar Wind Speed The heating and acceleration of the solar wind remains one of the unsolved fundamental problems in heliophysics. It is usually observed that the proton temperature T $_ i $ is highly correlated with the solar wind speed V $_SW$, while the electron temperature T $_ e $ shows anticorrelation or no clear correlation with the solar wind speed. Here, we inspect both Parker Solar Probe (PSP) and WIND data, and compare the observations with simulation results. PSP observations below 30 solar radii clearly show a positive correlatio ... Shi, Chen; Velli, Marco; Lionello, Roberto; Sioulas, Nikos; Huang, Zesen; Halekas, Jasper; Tenerani, Anna; eville, Victor; Dakeyo, Jean-Baptiste; c, Milan; Bale, Stuart; Published by: \apj Published on: feb YEAR: 2023   DOI: 10.3847/1538-4357/acb341 Parker Data Used; Solar wind; Alfven waves; Solar coronal heating; 1534; 23; 1989; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
Parker Solar Probe Encounters the Leg of a Coronal Mass Ejection at 14 Solar Radii We use Parker Solar Probe (PSP) observations to report the first direct measurements of the particle and field environments while crossing the leg of a coronal mass ejection (CME) very close to the Sun (\raisebox-0.5ex\textasciitilde14 Rs). An analysis that combines imaging from 1 au and PSP with a CME model, predicts an encounter time and duration that correspond to an unusual, complete dropout in low-energy solar energetic ions from H-Fe, observed by the Integrated Science Investigation of the Sun (IS\ensuremath\odotIS). T ... McComas, D.~J.; Sharma, T.; Christian, E.~R.; Cohen, C.~M.~S.; Desai, M.~I.; Hill, M.~E.; Khoo, L.~Y.; Matthaeus, W.~H.; Mitchell, D.~G.; Pecora, F.; Rankin, J.~S.; Schwadron, N.~A.; Szalay, J.~R.; Shen, M.~M.; Braga, C.~R.; Mostafavi, P.~S.; Bale, S.~D.; Published by: \apj Published on: feb YEAR: 2023   DOI: 10.3847/1538-4357/acab5e Parker Data Used; Solar coronal mass ejections; interplanetary magnetic fields; Interplanetary medium; Interplanetary particle acceleration; Solar energetic particles; Solar wind; Solar coronal heating; Solar magnetic flux emergence; 310; 824; 825; 826; 1491; 1534; 1989; 2000 |
Context. The fast solar wind is known to emanate from polar coronal holes. \ Aims: This Letter reports the first estimate of the expansion rate of polar coronal flows performed by the Metis coronagraph on board Solar Orbiter. \ Methods: By exploiting simultaneous measurements in polarized white light and ultraviolet intensity of the neutral hydrogen Lyman-\ensuremath\alpha line, it was possible to extend observations of the outflow velocity of the main component of the solar wind from polar coronal holes out to 5.5 R$_\ensur ... Telloni, D.; Antonucci, E.; Adhikari, L.; Zank, G.~P.; Giordano, S.; Vai, M.; Zhao, L.; Andretta, V.; Burtovoi, A.; Capuano, G.~E.; Da Deppo, V.; De Leo, Y.; Fineschi, S.; Grimani, C.; Heinzel, P.; Jerse, G.; Landini, F.; Liberatore, A.; Moses, J.~D.; Naletto, G.; Nicolini, G.; Pancrazzi, M.; Romoli, M.; Russano, G.; Sasso, C.; Slemer, A.; Spadaro, D.; Stangalini, M.; Susino, R.; Teriaca, L.; Uslenghi, M.; Sorriso-Valvo, L.; Marino, R.; Perrone, D.; Amicis, R.; Bruno, R.; Published by: \aap Published on: feb YEAR: 2023   DOI: 10.1051/0004-6361/202245759 Parker Data Used; magnetohydrodynamics (MHD); Sun: corona; Solar wind; Sun: UV radiation |
A Data-constrained Scheme for the Reconstruction of Solar Wind Parameters in the Inner Heliosphere With the development of our industrial society, the reconstruction of solar wind parameters in the inner heliosphere becomes very important to understanding the interplanetary propagation of various types of space weather disturbance. However, the situ observations of solar wind parameters are only applicable to several points where spacecraft are located. Therefore, we have to rely on the numerical technologies to reconstruct the solar wind parameters. The scheme for the reconstruction of solar wind parameters can be classi ... Zhang, Man; Feng, Xueshang; Yang, Liping; Liu, Xiaojing; Published by: \apjs Published on: feb YEAR: 2023   DOI: 10.3847/1538-4365/acaddc |
We present the first comprehensive statistical study of the evolution of compressive and noncompressive magnetic field fluctuations in the inner heliosphere. Based on Parker Solar Probe (PSP) and Solar Orbiter data at various distances from the Sun, we show the general trends and compare them with Wind observations near 1 au. The paper analyzes solar wind power spectra of magnetic field fluctuations in the inertial and kinetic ranges of frequencies. We find a systematic steepening of the spectrum in the inertial range with t ... a, Jana; N\veme\vcek, Zden\vek; N\vemec, Franti\vsek; Verscharen, Daniel; Horbury, Timothy; Bale, Stuart; P\vrech, Lubom\; Published by: \apjl Published on: apr YEAR: 2023   DOI: 10.3847/2041-8213/acc531 |
The heating of ions and electrons due to turbulent dissipation plays a crucial role in the thermodynamics of the solar wind and other plasma environments. Using magnetic field and thermal plasma observations from the first two perihelia of the Parker Solar Probe, we model the relative heating rates as a function of the radial distance, magnetic spectra, and plasma conditions, enabling us to better characterize the thermodynamics of the inner heliosphere. We employ the Howes et al. steady-state cascade model, which considers ... Shankarappa, Niranjana; Klein, Kristopher; c, Mihailo; Published by: \apj Published on: apr YEAR: 2023   DOI: 10.3847/1538-4357/acb542 Parker Data Used; Solar wind; interplanetary turbulence; Space plasmas; Wavelet analysis; 1534; 830; 1544; 1918; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
At kinetic scales in the solar wind, instabilities transfer energy from particles to fluctuations in the electromagnetic fields while restoring plasma conditions towards thermodynamic equilibrium. We investigate the interplay between background turbulent fluctuations at the small-scale end of the inertial range and kinetic instabilities acting to reduce proton temperature anisotropy. We analyse in situ solar wind observations from the Solar Orbiter mission to develop a measure for variability in the magnetic field direction. ... Opie, Simon; Verscharen, Daniel; Chen, Christopher; Owen, Christopher; Isenberg, Philip; Published by: \aap Published on: apr YEAR: 2023   DOI: 10.1051/0004-6361/202345965 Parker Data Used; instabilities; turbulence; Solar wind; Sun: heliosphere; plasmas; magnetic fields; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
NIRwave: A wave-turbulence-driven solar wind model constrained by PSP observations \ Aims: We generate a model description of the solar wind based on an explicit wave-turbulence-driven heating mechanism, and constrain our model with observational data. \ Methods: We included an explicit coronal heating source term in the general 3D magnetohydrodynamic code NIRVANA to simulate the properties of the solar wind. The adapted heating mechanism is based on the interaction and subsequent dissipation of counter- propagating Alfv\ en waves in the solar corona, accounting for a turbulent heating rate Q$_p$. The sola ... Schleich, S.; Saikia, Boro; Ziegler, U.; Güdel, M.; Bartel, M.; Published by: \aap Published on: apr YEAR: 2023   DOI: 10.1051/0004-6361/202245009 Parker Data Used; magnetohydrodynamics (MHD); Solar wind; Sun: activity; turbulence; waves; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Context. Whistler waves are electromagnetic waves produced by electron- driven instabilities, which in turn can reshape the electron distributions via wave-particle interactions. In the solar wind they are one of the main candidates for explaining the scattering of the strahl electron population into the halo at increasing radial distances from the Sun and for subsequently regulating the solar wind heat flux. However, it is unclear what type of instability dominates to drive whistler waves in the solar wind. \ Aims: Our goal ... Froment, C.; Agapitov, O.~V.; Krasnoselskikh, V.; Karbashewski, S.; de Wit, Dudok; Larosa, A.; Colomban, L.; Malaspina, D.; Kretzschmar, M.; Jagarlamudi, V.~K.; Bale, S.~D.; Bonnell, J.~W.; Mozer, F.~S.; Pulupa, M.; Published by: \aap Published on: apr YEAR: 2023   DOI: 10.1051/0004-6361/202245140 Parker Data Used; Sun: heliosphere; Solar wind; waves; plasmas; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
2022 |
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 |
Prior observations of the near-Sun solar wind (sunward of 0.25 au) identified frequent, intense plasma waves near the local electron cyclotron frequency (f $_ce$), and its harmonics. In this Letter, it is shown that near-f $_ce$ wave properties are consistent with generation via interaction between the observing spacecraft s ion wake and the ambient plasma and magnetic fields. This result implies that many observed near-f $_ce$ waves are not intrinsic to the unobstructed solar wind flow, and therefore are unlikely to play a ... Malaspina, David; Tigik, Sabrina; Vaivads, Andris; Published by: \apjl Published on: sep YEAR: 2022   DOI: 10.3847/2041-8213/ac8c8f Parker Data Used; Solar wind; space vehicles; Space plasmas; 1534; 1549; 1544 |
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 |
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 |
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 |
The heliospheric ambipolar potential inferred from sunward-propagating halo electrons We provide evidence that the sunward-propagating half of the solar wind electron halo distribution evolves without scattering in the inner heliosphere. We assume the particles conserve their total energy and magnetic moment, and perform a Liouville mapping on electron pitch angle distributions measured by the Parker Solar Probe SPAN-E instrument. Namely, we show that the distributions are consistent with Liouville s theorem if an appropriate interplanetary potential is chosen. This potential, an outcome of our fitting meth ... Horaites, Konstantinos; Boldyrev, Stanislav; Published by: \mnras Published on: oct YEAR: 2022   DOI: 10.1093/mnras/stac2051 Parker Data Used; plasmas; Solar wind; 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 |
Higher-order Turbulence Statistics in the Sub-Alfv\ enic Solar Wind Observed by Parker Solar Probe Parker Solar Probe has been the first spacecraft to enter the deep corona below the Alfv\ en critical point. Here we examine the higher-order statistical properties of magnetic-field fluctuations in the sub-Alfv\ enic solar wind and compare the results with the neighboring super-Alfv\ enic region. The intermittency and multifractal properties are analyzed by inspecting the probability density functions, the scale- dependent kurtosis, and fractal spectrum of magnetic-field fluctuations. It is found that the magnetic-field flu ... Zhang, J.; Huang, S.~Y.; Yuan, Z.~G.; Jiang, K.; Xu, S.~B.; Bandyopadhyay, R.; Wei, Y.~Y.; Xiong, Q.~Y.; Wang, Z.; Yu, L.; Lin, R.~T.; Published by: \apj Published on: oct YEAR: 2022   DOI: 10.3847/1538-4357/ac8c34 Parker Data Used; Solar wind; interplanetary turbulence; 1534; 830 |
Zhao, Jinsong; Malaspina, David; de Wit, Dudok; Pierrard, Viviane; Voitenko, Yuriy; Lapenta, Giovanni; Poedts, Stefaan; Bale, Stuart; Kasper, Justin; Larson, Davin; Livi, Roberto; Whittlesey, Phyllis; Published by: \apjl Published on: oct YEAR: 2022   DOI: 10.3847/2041-8213/ac92e3 Parker Data Used; Solar wind; Plasma physics; Space plasmas; 1534; 2089; 1544 |
Observation and Modeling of the Solar Wind Turbulence Evolution in the Sub-Mercury Inner Heliosphere Telloni, Daniele; Adhikari, Laxman; Zank, Gary; Hadid, Lina; anchez-Cano, Beatriz; Sorriso-Valvo, Luca; Zhao, Lingling; Panasenco, Olga; Shi, Chen; Velli, Marco; Susino, Roberto; Verscharen, Daniel; Milillo, Anna; Alberti, Tommaso; Narita, Yasuhito; Verdini, Andrea; Grimani, Catia; Bruno, Roberto; Amicis, Raffaella; Perrone, Denise; Marino, Raffaele; Carbone, Francesco; Califano, Francesco; Malara, Francesco; Stawarz, Julia; Laker, Ronan; Liberatore, Alessandro; Bale, Stuart; Kasper, Justin; Heyner, Daniel; de Wit, Thierry; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Case, Anthony; Korreck, Kelly; Larson, Davin; Livi, Roberto; Stevens, Michael; Whittlesey, Phyllis; Auster, Hans-Ulrich; Richter, Ingo; Published by: \apjl Published on: oct YEAR: 2022   DOI: 10.3847/2041-8213/ac9624 Parker Data Used; Magnetohydrodynamics; Alfven waves; Space plasmas; interplanetary turbulence; Heliosphere; Solar wind; 1964; 23; 1544; 830; 711; 1534 |
Cross-scale Correlations in Imbalanced Solar Wind Turbulence: Parker Solar Probe Observations Zhao, G.~Q.; Meyrand, R.; Feng, H.~Q.; Wu, D.~J.; Kasper, J.~C.; Published by: \apj Published on: oct YEAR: 2022   DOI: 10.3847/1538-4357/ac9380 Parker Data Used; Solar wind; interplanetary turbulence; Solar coronal heating; Space plasmas; Plasma physics; 1534; 830; 1989; 1544; 2089 |
Magnetic Switchbacks Heat the Solar Corona Akhavan-Tafti, M.; Kasper, J.; Huang, J.; Thomas, L.; Published by: \apjl Published on: oct YEAR: 2022   DOI: 10.3847/2041-8213/ac913d Parker Data Used; Solar coronal heating; Solar magnetic reconnection; Solar wind; Heliosphere; 1989; 1504; 1534; 711 |
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 |
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 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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |