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Found 748 entries in the Bibliography.
Showing entries from 1 through 50
| 2022 |
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We examine statistics of magnetic-field vector components to explore how intermittency evolves from near-Sun plasma to radial distances as large as 10 au. Statistics entering the analysis include autocorrelation, magnetic structure functions of the order of n (SF$_ n $), and scale-dependent kurtosis (SDK), each grouped in ranges of heliocentric distance. The Goddard Space Flight Center Space Physics Data Facility provides magnetic-field measurements for resolutions of 6.8 ms for Parker Solar Probe, 6 s for Helios, and 1.92 s ... Cuesta, Manuel; Parashar, Tulasi; Chhiber, Rohit; Matthaeus, William; Published by: \apjs Published on: mar YEAR: 2022 DOI: 10.3847/1538-4365/ac45fa Parker Data Used; Solar wind; interplanetary magnetic fields; Space plasmas; interplanetary turbulence; Interplanetary physics; 1534; 824; 1544; 830; 827; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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Relativistic Particle Transport and Acceleration in Structured Plasma Turbulence We discuss the phenomenon of energization of relativistic charged particles in three-dimensional incompressible MHD turbulence and the diffusive properties of the motion of the same particles. We show that the random electric field induced by turbulent plasma motion leads test particles moving in a simulated box to be accelerated in a stochastic way, a second-order Fermi process. A small fraction of these particles happen to be trapped in large- scale structures, most likely formed due to the interaction of islands in the tu ... Pezzi, Oreste; Blasi, Pasquale; Matthaeus, William; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac5332 Parker Data Used; Magnetohydrodynamics; cosmic rays; Particle astrophysics; 1964; 329; 96; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics |
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Core Electron Heating by Triggered Ion Acoustic Waves in the Solar Wind Perihelion passes on Parker Solar Probe orbits 6-9 have been studied to show that solar wind core electrons emerged from 15 solar radii with a temperature of 55 \ensuremath\pm 5 eV, independent of the solar wind speed, which varied from 300 to 800 km s$^-1$. After leaving 15 solar radii and in the absence of triggered ion acoustic waves at greater distances, the core electron temperature varied with radial distance, R, in solar radii, as 1900R $^-4/3$ eV because of cooling produced by the adiabatic expansion. The coefficient ... Mozer, F.~S.; Bale, S.~D.; Cattell, C.~A.; Halekas, J.; Vasko, I.~Y.; Verniero, J.~L.; Kellogg, P.~J.; Published by: \apjl Published on: mar YEAR: 2022 DOI: 10.3847/2041-8213/ac5520 Parker Data Used; Solar corona; Solar wind; 1483; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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We use data from the first six encounters of the Parker Solar Probe and employ the partial variance of increments (PVI) method to study the statistical properties of coherent structures in the inner heliosphere with the aim of exploring physical connections between magnetic field intermittency and observable consequences such as plasma heating and turbulence dissipation. Our results support proton heating localized in the vicinity of, and strongly correlated with, magnetic structures characterized by PVI \ensuremath\geq 1. W ... Sioulas, Nikos; Velli, Marco; Chhiber, Rohit; Vlahos, Loukas; Matthaeus, William; Bandyopadhyay, Riddhi; Cuesta, Manuel; Shi, Chen; Bowen, Trevor; Qudsi, Ramiz; Stevens, Michael; Bale, Stuart; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4fc1 Parker Data Used; Solar wind; Space plasmas; Plasma astrophysics; 1534; 1544; 1261; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Langmuir-Slow Extraordinary Mode Magnetic Signature Observations with Parker Solar Probe Radio emission from interplanetary shocks, planetary foreshocks, and some solar flares occurs in the so-called plasma emission framework. The generally accepted scenario begins with electrostatic Langmuir waves that are driven by a suprathermal electron beam on the Landau resonance. These Langmuir waves then mode-convert to freely propagating electromagnetic emissions at the local plasma frequency f $_ pe $ and/or its harmonic 2f $_ pe $. However, the details of the physics of mode conversion are unclear, and so far the ... Larosa, A.; de Wit, Dudok; Krasnoselskikh, V.; Bale, S.~D.; Agapitov, O.; Bonnell, J.; Froment, C.; Goetz, K.; Harvey, P.; Halekas, J.; Kretzschmar, M.; MacDowall, R.; Malaspina, David; Moncuquet, M.; Niehof, J.; Pulupa, M.; Revillet, C.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4e85 Parker Data Used; Solar wind; Plasma physics; Space plasmas; 1534; 2089; 1544 |
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We present observations of \ensuremath\gtrsim10-100 keV nucleon$^-1$ suprathermal (ST) H, He, O, and Fe ions associated with crossings of the heliospheric current sheet (HCS) at radial distances of <0.1 au from the Sun. Our key findings are as follows: (1) very few heavy ions are detected during the first full crossing, the heavy-ion intensities are reduced during the second partial crossing and peak just after the second crossing; (2) ion arrival times exhibit no velocity dispersion; (3) He pitch-angle distributions track t ... Desai, M.~I.; Mitchell, D.~G.; McComas, D.~J.; Drake, J.~F.; Phan, T.; Szalay, J.~R.; Roelof, E.~C.; Giacalone, J.; Hill, M.~E.; Christian, E.~R.; Schwadron, N.~A.; McNutt, R.~L.; Wiedenbeck, M.~E.; Joyce, C.; Cohen, C.~M.~S.; Davis, A.~J.; Krimigis, S.~M.; Leske, R.~A.; Matthaeus, W.~H.; Malandraki, O.; Mewaldt, R.~A.; Labrador, A.; Stone, E.~C.; Bale, S.~D.; Verniero, J.; Rahmati, A.; Whittlesey, P.; Livi, R.; Larson, D.; Pulupa, M.; MacDowall, R.~J.; Niehof, J.~T.; Kasper, J.~C.; Horbury, T.~S.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4961 Parker Data Used; The Sun; Solar magnetic reconnection; Interplanetary particle acceleration; interplanetary magnetic fields; Heliosphere; 1693; 1504; 826; 824; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Context. Solar Orbiter and Parker Solar Probe jointly observed the solar wind for the first time in June 2020, capturing data from very different solar wind streams: calm, Alfv\ enic wind and also highly dynamic large-scale structures. Context. Our aim is to understand the origin and characteristics of the highly dynamic solar wind observed by the two probes, particularly in the vicinity of the heliospheric current sheet (HCS). \ Methods: We analyzed the plasma data obtained by Parker Solar Probe and Solar Orbiter in situ du ... RĂ©ville, V.; Fargette, N.; Rouillard, A.~P.; Lavraud, B.; Velli, M.; Strugarek, A.; Parenti, S.; Brun, A.~S.; Shi, C.; Kouloumvakos, A.; Poirier, N.; Pinto, R.~F.; Louarn, P.; Fedorov, A.; Owen, C.~J.; enot, V.; Horbury, T.~S.; Laker, R.; Brien, H.; Angelini, V.; Fauchon-Jones, E.; Kasper, J.~C.; Published by: \aap Published on: mar YEAR: 2022 DOI: 10.1051/0004-6361/202142381 Parker Data Used; Solar wind; magnetohydrodynamics (MHD); magnetic reconnection; methods: numerical; methods: data analysis; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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The S-shaped magnetic structure in the solar wind formed by the twisting of magnetic field lines is called a switchback, whose main characteristics are the reversal of the magnetic field and the significant increase in the solar wind radial velocity. We identify 242 switchbacks during the first two encounters of Parker Solar Probe. Statistics methods are applied to analyze the distribution and the rotation angle and direction of the magnetic field rotation of the switchbacks. The diameter of switchbacks is estimated with a m ... Meng, Ming-Ming; Liu, Ying; Chen, Chong; Wang, Rui; Published by: Research in Astronomy and Astrophysics Published on: mar YEAR: 2022 DOI: 10.1088/1674-4527/ac49e4 Parker Data Used; ISM: magnetic fields; methods: statistical; (Sun:) solar wind; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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An Extended and Fragmented Alfv\ en Zone in the Young Solar Wind Motivated by theoretical, numerical, and observational evidence, we explore the possibility that the critical transition between sub-Alfv\ enic flow and super-Alfv\ enic flow in the solar atmosphere takes place in fragmented and disconnected subvolumes within a general Alfv\ en critical zone. The initial observations of sub-Alfv\ enic periods by Parker Solar Probe near 16 R$_\ensuremath\odot$ do not yet provide sufficient evidence to distinguish this possibility from that of a folded surface that separates simply-connected r ... Chhiber, Rohit; Matthaeus, William; Usmanov, Arcadi; Bandyopadhyay, Riddhi; Goldstein, Melvyn; Published by: \mnras Published on: mar YEAR: 2022 DOI: 10.1093/mnras/stac779 |
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Categorizing MHD Discontinuities in the Inner Heliosphere by Utilizing the PSP Mission The interplanetary discontinuities (IDs) have been widely observed in astrophysical and space plasmas, while their characteristics and evolutions within 0.3 AU are still unclear due to the limitation of spacecraft orbits in previous missions. Here, we report three ID events, including a rotational discontinuity (RD), a tangential discontinuity (TD), and a suspected contact discontinuity (CD), detected by the Parker Solar Probe in a previously unexplored region of the heliosphere as close to the Sun as 0.13 AU. By the combina ... Liu, Y.~Y.; Fu, H.~S.; Cao, J.~B.; Yu, Y.; Liu, C.~M.; Wang, Z.; Guo, Z.~Z.; He, R.~J.; Published by: Journal of Geophysical Research (Space Physics) Published on: mar YEAR: 2022 DOI: 10.1029/2021JA029983 |
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PSP Observations of a Slow Shock Pair Bounding a Large-Scale Plasmoid/Macro Magnetic Hole Slow shocks are introduced to be the main dissipation sites in Petschek reconnection model, but they are seldom observed in interplanetary space. We report a slow shock pair bounding a plasmoid/macro magnetic hole observed by Parker Solar Probe. The jump conditions across the shocks are examined and confirmed to satisfy the Rankine-Hugoniot relations. The flow speed in the preshock and postshock regions of both shocks match up with the characteristics of slow shocks. The slow shock pair is suggested to be a part of a curved ... Zhou, Zilu; Xu, Xiaojun; Zuo, Pingbing; Wang, Yi; Wang, Ludi; Ye, Yudong; Wang, Ming; Chang, Qing; Wang, Xing; Luo, Lei; Published by: \grl Published on: mar YEAR: 2022 DOI: 10.1029/2021GL097564 Parker Data Used; slow shocks; magnetic reconnection; Solar wind; magnetic hole |
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We propose a transport theory for the kinetic evolution of solar-wind electrons in the heliosphere. We derive a gyro-averaged kinetic transport equation that accounts for the spherical expansion of the solar wind and the geometry of the Parker spiral magnetic field. To solve our three-dimensional kinetic equation, we develop a mathematical approach that combines the Crank-Nicolson scheme in velocity space and a finite-difference Euler scheme in configuration space. We initialize our model with isotropic electron distribution ... Jeong, Seong-Yeop; Verscharen, Daniel; Vocks, Christian; Abraham, Joel; Owen, Christopher; Wicks, Robert; Fazakerley, Andrew; Stansby, David; Ber\vci\vc, Laura; Nicolaou, Georgios; Rueda, Jeffersson; Bakrania, Mayur; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac4805 Parker Data Used; Solar wind; Space plasmas; Heliosphere; Theoretical models; 1534; 1544; 711; 2107; Physics - Space Physics |
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An analytical model for dust impact voltage signals and its application to STEREO/WAVES data Context. Dust impacts have been observed using radio and wave instruments onboard spacecraft since the 1980s. Voltage waveforms show typical impulsive signals generated by dust grains. \ Aims: We aim at developing models of how signals are generated to be able to link observed electric signals to the physical properties of the impacting dust. To validate the model, we use the Time Domain Sampler (TDS) subsystem of the STEREO/WAVES instrument which generates high- cadence time series of voltage pulses for each monopole. \ Met ... Babic, Rackovic; Zaslavsky, A.; Issautier, K.; Meyer-Vernet, N.; Onic, D.; Published by: \aap Published on: mar YEAR: 2022 DOI: 10.1051/0004-6361/202142508 Solar wind; Sun: heliosphere; methods: analytical; methods: data analysis; meteorites; meteors; Meteoroids; Interplanetary medium |
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Recent solar physics missions have shown the definite role of waves and magnetic fields deep in the inner corona, at the chromosphere- corona interface, where dramatic and physically dominant changes occur. HiRISE (High Resolution Imaging and Spectroscopy Explorer), the ambitious new generation ultra-high resolution, interferometric, and coronagraphic, solar physics mission, proposed in response to the ESA Voyage 2050 Call, would address these issues and provide the best-ever and most complete solar observatory, capable of u ... elyi, Robertus; e, Luc; Fludra, Andrzej; Mathioudakis, Mihalis; Amari, T.; Belucz, B.; Berrilli, F.; Bogachev, S.; ee, Bols\; Bothmer, V.; Brun, S.; Dewitte, S.; de Wit, Dudok; Faurobert, M.; Gizon, L.; Gyenge, N.; os, M.~B.; Labrosse, N.; Matthews, S.; Meftah, M.; Morgan, H.; e, Pall\; Rochus, P.; Rozanov, E.; Schmieder, B.; Tsinganos, K.; Verwichte, E.; Zharkov, S.; Zuccarello, F.; Wimmer-Schweingruber, R.; Published by: Experimental Astronomy Published on: mar YEAR: 2022 DOI: 10.1007/s10686-022-09831-2 Solar physics mission; Ultra-high resolution; Interferometry; Coronagraph; Solar atmosphere; photosphere; chromosphere; Corona |
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eville, Victor; Velli, Marco; Panasenco, Olga; Tenerani, Anna; Shi, Chen; Badman, Samuel; Bale, Stuart; Kasper, J.~C.; Stevens, Michael; Korreck, Kelly; Bonnell, J.~W.; Case, Anthony; de Wit, Thierry; Goetz, Keith; Harvey, Peter; Larson, Davin; Livi, Roberto; Malaspina, David; MacDowall, Robert; Pulupa, Marc; Whittlesey, Phyllis; Published by: \apjs Published on: mar YEAR: 2022 DOI: 10.3847/1538-4365/ac532e |
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The acceleration of charged particles by interplanetary shocks (IPs) can drain a nonnegligible fraction of the plasma pressure. In this study, we have selected 17 IPs observed in situ at 1 au by the Advanced Composition Explorer and the Wind spacecraft, and 1 shock at 0.8 au observed by Parker Solar Probe. We have calculated the time-dependent partial pressure of suprathermal and energetic particles (smaller and greater than 50 keV for protons and 30 keV for electrons, respectively) in both the upstream and downstream region ... David, Liam; Fraschetti, Federico; Giacalone, Joe; Wimmer-Schweingruber, Robert; Berger, Lars; Lario, David; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac54af Parker Data Used; Interplanetary shocks; Interplanetary particle acceleration; Space plasmas; 829; 826; 1544; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics; Physics - Space Physics |
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The solar wind is a highly turbulent plasma for which the mean rate of energy transfer É› has been measured for a long time using the Politano-Pouquet (PP98) exact law. However, this law assumes statistical homogeneity that can be violated by the presence of discontinuities. Here, we introduce a new method based on the inertial dissipation $ D _I^{\sigma }$ whose analytical form is derived from incompressible magnetohydrodynamics; it can be considered as a weak and local (in space) formulation of the PP98 law whose expressio ... David, V.; Galtier, S.; Sahraoui, F.; Hadid, L.~Z.; Published by: \apj Published on: mar YEAR: 2022 DOI: 10.3847/1538-4357/ac524b Parker Data Used; interplanetary turbulence; Space plasmas; Solar wind; 830; 1544; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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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 |
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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, JĂ¼rgen; 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 |
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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 |
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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 |
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One of the major discoveries of NASA s 1979-1991 Pioneer Venus Orbiter is that the nightside ionosphere becomes filamentary at high altitude, forming comet-like tail rays. Pioneer Venus Orbiter could not establish how much farther into the wake of Venus tail rays extend, nor understand how they form. Here we present plasma and fields data from the fourth flyby of Venus by NASA s Parker Solar Probe consistent with an intercept with an ionospheric tail ray. The observations unambiguously demonstrate that Venusian Ionotail Rays ... Collinson, Glyn; Ramstad, Robin; Frahm, Rudy; Wilson, Lynn; Xu, Shaosui; Whittlesey, Phyllis; Brecht, Stephen; Ledvina, Stephen; Published by: \grl Published on: jan YEAR: 2022 DOI: 10.1029/2021GL096485 Parker Data Used; Venus; Tail Rays; ionosphere; upper hybrid emission; parker solar probe; Atmospheric escape |
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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 |
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Clouds of Spacecraft Debris Liberated by Hypervelocity Dust Impacts on Parker Solar Probe Hypervelocity impacts on spacecraft surfaces produce a wide range of effects including transient plasma clouds, surface material ablation, and for some impacts, the liberation of spacecraft material as debris clouds. This study examines debris-producing impacts on the Parker Solar Probe spacecraft as it traverses the densest part of the zodiacal cloud: the inner heliosphere. Hypervelocity impacts by interplanetary dust grains on the spacecraft that produce debris clouds are identified and examined. Impact-generated plasma an ... Malaspina, David; Stenborg, Guillermo; Mehoke, Doug; Al-Ghazwi, Adel; Shen, Mitchell; Hsu, Hsiang-Wen; Iyer, Kaushik; Bale, Stuart; de Wit, Thierry; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac3bbb |
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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 |
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Using the Parker Solar Probe FIELDS bandpass-filter data and SWEAP electron data from Encounters 1 through 9, we show statistical properties of narrowband whistlers from \raisebox-0.5ex\textasciitilde16 R $_s$ to \raisebox-0.5ex\textasciitilde130 R $_s$, and compare wave occurrence to electron properties including beta, temperature anisotropy, and heat flux. Whistlers are very rarely observed inside \raisebox-0.5ex\textasciitilde28 R $_s$ (\raisebox-0.5ex\textasciitilde0.13 au). Outside 28 R $_s$, they occur within a narrow ... Cattell, C.; Breneman, A.; Dombeck, J.; Hanson, E.; Johnson, M.; Halekas, J.; Bale, S.~D.; de Wit, Dudok; Goetz, K.; Goodrich, K.; Malaspina, D.; Pulupa, M.; Case, T.; Kasper, J.~C.; Larson, D.; Stevens, M.; Whittlesey, P.; Published by: \apjl Published on: jan YEAR: 2022 DOI: 10.3847/2041-8213/ac4015 Parker Data Used; 1534; 1261; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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The electron VDF in the solar wind consists of a Maxwellian core, a suprathermal halo, a field-aligned component strahl, and an energetic superhalo that deviates from the equilibrium. Whistler wave turbulence is thought to resonantly scatter the observed electron velocity distribution. Wave-particle interactions that contribute to Whistler wave turbulence are introduced into a Fokker-Planck kinetic transport equation that describes the interaction between the suprathermal electrons and the Whistler waves. A recent numerical ... Tang, Bofeng; Zank, Gary; Kolobov, Vladimir; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac36c9 |
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Strong Perpendicular Velocity-space Diffusion in Proton Beams Observed by Parker Solar Probe The SWEAP instrument suite on Parker Solar Probe (PSP) has detected numerous proton beams associated with coherent, circularly polarized, ion-scale waves observed by PSP s FIELDS instrument suite. Measurements during PSP Encounters 4-8 revealed pronounced complex shapes in the proton velocity distribution functions (VDFs), in which the tip of the beam undergoes strong perpendicular diffusion, resulting in VDF level contours that resemble a hammerhead. We refer to these proton beams, with their attendant hammerhead fe ... Verniero, J.~L.; Chandran, B.~D.~G.; Larson, D.~E.; Paulson, K.; Alterman, B.~L.; Badman, S.; Bale, S.~D.; Bonnell, J.~W.; Bowen, T.~A.; de Wit, Dudok; Kasper, J.~C.; Klein, K.~G.; Lichko, E.; Livi, R.; McManus, M.~D.; Rahmati, A.; Verscharen, D.; Walters, J.; Whittlesey, P.~L.; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac36d5 Parker Data Used; 1544; 23; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Based on the Parker Solar Probe mission, this paper presents the observations of two correlations in solar wind turbulence near the Sun for the first time, demonstrating the clear existence of the following two correlations. One is positive correlation between the proton temperature and turbulent magnetic energy density. The other is negative correlation between the spectral index and magnetic helicity. It is found that the former correlation has a maximum correlation coefficient (CC) at the wavenumber k \ensuremath\rho $_ p ... Zhao, G.~Q.; Lin, Y.; Wang, X.~Y.; Feng, H.~Q.; Wu, D.~J.; Kasper, J.~C.; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac3747 |
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A Study of an Equatorial Coronal Hole Observed at the First Parker Solar Probe Perihelion In this study, we present an observational analysis of a coronal hole (CH) observed on 2018 November 1 and solar wind (SW) that originated from it, using the Solar Dynamics Observatory, the Parker Solar Probe (PSP) observations at 68 solar radii, ACE and WIND data at 1 au, and interplanetary scintillation (IPS) observations from 0.2 to 1 au. The CH-originated SW stream was observed by L1 on 2018 November 4 and by PSP on 2018 November 15. We examined the CH for nine Carrington Rotations (CR) and find that the SW stream to rea ... Karna, Nishu; Berger, Mitchell; Asgari-Targhi, Mahboubeh; Paulson, Kristoff; Fujiki, Ken; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac3c46 |
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We utilize the data from the Parker Solar Probe mission at its first perihelion to investigate the three-dimensional (3D) anisotropies and scalings of solar wind turbulence for the total, perpendicular, and parallel magnetic-field fluctuations at kinetic scales in the inner heliosphere. By calculating the five-point second-order structure functions, we find that the three characteristic lengths of turbulence eddies for the total and the perpendicular magnetic-field fluctuations in the local reference frame $(\hatL_\perp ,\ha ... Zhang, J.; Huang, S.~Y.; He, J.~S.; Wang, T.~Y.; Yuan, Z.~G.; Deng, X.~H.; Jiang, K.; Wei, Y.~Y.; Xu, S.~B.; Xiong, Q.~Y.; Lin, R.~T.; Yu, L.; Published by: \apjl Published on: jan YEAR: 2022 DOI: 10.3847/2041-8213/ac4027 |
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Simulation of Plasma Emission in Magnetized Plasmas The recent Parker Solar Probe observations of type III radio bursts show that the effects of the finite background magnetic field can be an important factor in the interpretation of data. In the present paper, the effects of the background magnetic field on the plasma-emission process, which is believed to be the main emission mechanism for solar coronal and interplanetary type III radio bursts, are investigated by means of the particle-in-cell simulation method. The effects of the ambient magnetic field are systematically s ... Lee, Sang-Yun; Yoon, Peter; Lee, Ensang; Tu, Weichao; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac32bb Parker Data Used; 1544; 1534; Astrophysics - Solar and Stellar Astrophysics |
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We report small-scale magnetic flux ropes via the in situ measurements from the Parker Solar Probe during the first six encounters, and present additional analyses to supplement our prior work in Chen et al. These flux ropes are detected by the Grad-Shafranov-based algorithm, with their durations and scale sizes ranging from 10 s to \ensuremath\lesssim1 hr and from a few hundred kilometers to 10$^-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 |
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Slow Shock Formation Upstream of Reconnecting Current Sheets The formation, development, and impact of slow shocks in the upstream regions of reconnecting current layers are explored. Slow shocks have been documented in the upstream regions of magnetohydrodynamic (MHD) simulations of magnetic reconnection as well as in similar simulations with the kglobal kinetic macroscale simulation model. They are therefore a candidate mechanism for preheating the plasma that is injected into the current layers that facilitate magnetic energy release in solar flares. Of particular interest is their ... Arnold, H.; Drake, J.~F.; Swisdak, M.; Guo, F.; Dahlin, J.~T.; Zhang, Q.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac423b Parker Data Used; 1504; 2086; 2089; 1544; Physics - Plasma Physics; Physics - Space Physics |
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Improving the Alfv\ en Wave Solar Atmosphere Model Based on Parker Solar Probe Data In van der Holst et al. (2019), we modeled the solar corona and inner heliosphere of the first encounter of NASA s Parker Solar Probe (PSP) using the Alfv\ en Wave Solar atmosphere Model (AWSoM) with Air Force Data Assimilative Photospheric flux Transport- Global Oscillation Network Group magnetograms, and made predictions of the state of the solar wind plasma for the first encounter. AWSoM uses low-frequency Alfv\ en wave turbulence to address the coronal heating and acceleration. Here, we revise our simulations, by introdu ... van der Holst, B.; Huang, J.; Sachdeva, N.; Kasper, J.~C.; Manchester, W.~B.; Borovikov, D.; Chandran, B.~D.~G.; Case, A.~W.; Korreck, K.~E.; Larson, D.; Livi, R.; Stevens, M.; Whittlesey, P.; Bale, S.~D.; Pulupa, M.; Malaspina, D.~M.; Bonnell, J.~W.; Harvey, P.~R.; Goetz, K.; MacDowall, R.~J.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac3d34 |
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A Fundamental Instability for the Solar Wind As has been known nearly since the beginning of space research with satellites and rockets that the temperature of the atmosphere of our Sun rises rapidly from the photosphere at about 6000 K to the order of 10$^6$ K. The major heating of the solar wind apparently occurs in a narrow region, the transition region, just above the chromosphere, a region where remote sensing of atomic energy levels shows a temperature of 10$^6$ deg. However, since the early days of the recognition of the solar wind it has been recognized that th ... Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac32e0 |
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Parker Solar Probe Imaging of the Night Side of Venus We present images of Venus from the Wide-Field Imager for Parker Solar Probe (WISPR) telescope on board the Parker Solar Probe (PSP) spacecraft, obtained during PSP s third and fourth flybys of Venus on 2020 July 11 and 2021 February 20, respectively. Thermal emission from the surface is observed on the night side, representing the shortest wavelength observations of this emission ever, the first detection of the Venusian surface by an optical telescope observing below 0.8 \ensuremath\mum. Consistent with previous observatio ... Wood, Brian; Hess, Phillip; Lustig-Yaeger, Jacob; Gallagher, Brendan; Korwan, Daniel; Rich, Nathan; Stenborg, Guillermo; Thernisien, Arnaud; Qadri, Syed; Santiago, Freddie; Peralta, Javier; Arney, Giada; Izenberg, Noam; Vourlidas, Angelos; Linton, Mark; Howard, Russell; Raouafi, Nour; Published by: \grl Published on: feb YEAR: 2022 DOI: 10.1029/2021GL096302 |
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Alpha-Proton Differential Flow of the Young Solar Wind: Parker Solar Probe Observations The velocity of alpha particles relative to protons can vary depending on the solar wind type and distance from the Sun. Measurements from the previous spacecraft provided the alpha-proton differential velocities down to 0.3 au. The Parker Solar Probe (PSP) now enables insights into differential flows of the newly accelerated solar wind closer to the Sun for the first time. Here we study the difference between proton and alpha bulk velocities near PSP perihelia of encounters 3-7 when the core solar wind is in the field of vi ... Mostafavi, P.; Allen, R.~C.; McManus, M.~D.; Ho, G.~C.; Raouafi, N.~E.; Larson, D.~E.; Kasper, J.~C.; Bale, S.~D.; Published by: \apjl Published on: feb YEAR: 2022 DOI: 10.3847/2041-8213/ac51e1 Parker Data Used; 1534; 1544; 1492; 1476; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
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Turbulence in the Sub-Alfv\ enic Solar Wind The Parker Solar Probe (PSP) entered a region of sub-Alfv\ enic solar wind during encounter 8, and we present the first detailed analysis of low-frequency turbulence properties in this novel region. The magnetic field and flow velocity vectors were highly aligned during this interval. By constructing spectrograms of the normalized magnetic helicity, cross-helicity, and residual energy, we find that PSP observed primarily Alfv\ enic fluctuations, a consequence of the highly field-aligned flow that renders quasi-2D fluctuation ... Zank, G.~P.; Zhao, L.; Adhikari, L.; Telloni, D.; Kasper, J.~C.; Stevens, M.; Rahmati, A.; Bale, S.~D.; Published by: \apjl Published on: feb YEAR: 2022 DOI: 10.3847/2041-8213/ac51da |
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An Improved Technique for Measuring Plasma Density to High Frequencies on the Parker Solar Probe The correlation between the plasma density measured in space and the surface potential of an electrically conducting satellite body with biased electric field detectors has been recognized and used to provide density proxies. However, for Parker Solar Probe, this correlation has not produced quantitative density estimates over extended periods of time because it depends on the energy-dependent exponential variation of the photoemission spectrum, the electron temperature, the ratio of the biased surface area to the conducting ... Mozer, F.~S.; Bale, S.~D.; Kellogg, P.~J.; Larson, D.; Livi, R.; Romeo, O.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac4f42 Parker Data Used; 1534; 1476; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
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Recent in situ observations from the Parker Solar Probe (PSP) mission in the inner heliosphere near perihelia show evidence of ion beams, temperature anisotropies, and kinetic wave activity, which are likely associated with kinetic heating and acceleration processes of the solar wind. In particular, the proton beams were detected by PSP/Solar Probe Analyzers-Ion (SPAN-I) and related magnetic fluctuation spectra associated with ion-scale waves were observed by the FIELDS instrument. We present the ion velocity distribution fu ... Ofman, Leon; Boardsen, Scott; Jian, Lan; Verniero, Jaye; Larson, Davin; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac402c Parker Data Used; 1534; 1545; 1544; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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Using the Parker Solar Probe measurements, this Letter reports two new types of multiband electrostatic waves in and near the heliospheric current sheet. They are classified into the f < f $_ce$ and f > f $_ce$ multiband electrostatic waves, in which most (or all) of the bands in the former type are lower than f $_ce$, and all of the bands in the latter type are higher than f $_ce$, where f and f $_ce$ denotes the wave frequency and the electron cyclotron frequency, respectively. This Letter also exhibits observational evide ... Shi, Chen; Zhao, Jinsong; Malaspina, David; Bale, Stuart; Dong, Xiangcheng; Wang, Tieyan; Wu, Dejin; Published by: \apjl Published on: feb YEAR: 2022 DOI: 10.3847/2041-8213/ac4d37 |
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The von K\ arm\ an-Howarth equations give a starting basis for the classical turbulence theory. The formula for the magnetohydrodynamics von K\ arm\ an decay rate represents an energy source in many solar wind models with turbulence as the driver. However, it still lacks the radial trend comparison between the von K\ arm\ an decay rate, the energy supply rate, and the perpendicular heating rate based on direct observations of the solar wind. Here we carry out this kind of comparison for the first time using Parker Solar Prob ... Wu, Honghong; Tu, Chuanyi; He, Jiansen; Wang, Xin; Yang, Liping; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac4413 |
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Double-power-law Feature of Energetic Particles Accelerated at Coronal Shocks Recent observations have shown that in many large solar energetic particle (SEP) events the event-integrated differential spectra resemble double power laws. We perform numerical modeling of particle acceleration at coronal shocks propagating through a streamer-like magnetic field by solving the Parker transport equation, including protons and heavier ions. We find that for all ion species the energy spectra integrated over the simulation domain can be described by a double power law, and the break energy depends on the ion ... Yu, Feiyu; Kong, Xiangliang; Guo, Fan; Liu, Wenlong; Jiang, Zelong; Chen, Yao; Giacalone, Joe; Published by: \apjl Published on: feb YEAR: 2022 DOI: 10.3847/2041-8213/ac4cb3 1491; 1517; 1997; 1486; Astrophysics - Solar and Stellar Astrophysics |
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We analyze the micro-kinetic stability of the electron strahl in the solar wind depending on heliocentric distance. The oblique fast- magnetosonic/whistler (FM/W) instability has emerged in the literature as a key candidate mechanism for the effective scattering of the electron strahl into the electron halo population. Using data from the Parker Solar Probe (PSP) and Helios, we compare the measured strahl properties with the analytical thresholds for the oblique FM/W instability in the low- and high-\ensuremath\beta $_\ensur ... Jeong, Seong-Yeop; Abraham, Joel; Verscharen, Daniel; Ber\vci\vc, Laura; Stansby, David; Nicolaou, Georgios; Owen, Christopher; Wicks, Robert; Fazakerley, Andrew; Rueda, Jeffersson; Bakrania, Mayur; Published by: \apjl Published on: feb YEAR: 2022 DOI: 10.3847/2041-8213/ac4dff Parker Data Used; 1534; 1544; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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Flux Rope Merging and the Structure of Switchbacks in the Solar Wind A major discovery of Parker Solar Probe (PSP) was the presence of large numbers of localized increases in the radial solar wind speed and associated sharp deflections of the magnetic field- switchbacks (SBs). A possible generation mechanism of SBs is through magnetic reconnection between open and closed magnetic flux near the solar surface, termed interchange reconnection, that leads to the ejection of flux ropes (FRs) into the solar wind. Observations also suggest that SBs undergo merging, consistent with an FR picture of t ... Agapitov, O.~V.; Drake, J.~F.; Swisdak, M.; Bale, S.~D.; Horbury, T.~S.; Kasper, J.~C.; MacDowall, R.~J.; Mozer, F.~S.; Phan, T.~D.; Pulupa, M.; Raouafi, N.~E.; Velli, M.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac4016 Parker Data Used; 711; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
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At the end of 2020 September, the Parker Solar Probe (PSP) and BepiColombo were radially aligned: PSP was orbiting near 0.17 au and BepiColombo near 0.6 au. This geometry is of particular interest for investigating the evolution of solar wind properties at different heliocentric distances by observing the same solar wind plasma parcels. In this work, we use the magnetic field observations from both spacecraft to characterize both the topology of the magnetic field at different heliocentric distances (scalings, high-order sta ... Alberti, Tommaso; Milillo, Anna; Heyner, Daniel; Hadid, Lina; Auster, Hans-Ulrich; Richter, Ingo; Narita, Yasuhito; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac478d Parker Data Used; 1534; 994; 1964; 830 |
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In the lower solar coronal regions where the magnetic field is dominant, the Alfv\ en speed is much higher than the wind speed. In contrast, the near-Earth solar wind is strongly super- Alfv\ enic, i.e., the wind speed greatly exceeds the Alfv\ en speed. The transition between these regimes is classically described as the Alfv\ en point but may in fact occur in a distributed Alfv\ en critical region. NASA s Parker Solar Probe (PSP) mission has entered this region, as it follows a series of orbits that gradually approach ... Bandyopadhyay, R.; Matthaeus, W.~H.; McComas, D.~J.; Chhiber, R.; Usmanov, A.~V.; Huang, J.; Livi, R.; Larson, D.~E.; Kasper, J.~C.; Case, A.~W.; Stevens, M.; Whittlesey, P.; Romeo, O.~M.; Bale, S.~D.; Bonnell, J.~W.; de Wit, Dudok; Goetz, K.; Harvey, P.~R.; MacDowall, R.~J.; Malaspina, D.~M.; Pulupa, M.; Published by: \apjl Published on: feb YEAR: 2022 DOI: 10.3847/2041-8213/ac4a5c Parker Data Used; 1544; 1534; 824; 23; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
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In this paper we examine a low-energy solar energetic particle (SEP) event observed by IS\ensuremath\odotIS s Energetic Particle Instrument-Low (EPI-Lo) inside 0.18 au on 2020 September 30. This small SEP event has a very interesting time profile and ion composition. Our results show that the maximum energy and peak in intensity are observed mainly along the open radial magnetic field. The event shows velocity dispersion, and strong particle anisotropies are observed throughout the event, showing that more particles are stre ... Getachew, T.; McComas, D.~J.; Joyce, C.~J.; Palmerio, E.; Christian, E.~R.; Cohen, C.~M.~S.; Desai, M.~I.; Giacalone, J.; Hill, M.~E.; Matthaeus, W.~H.; McNutt, R.~L.; Mitchell, D.~G.; Mitchell, J.~G.; Rankin, J.~S.; Roelof, E.~C.; Schwadron, N.~A.; Szalay, J.~R.; Zank, G.~P.; Zhao, L.; Lynch, B.~J.; Phan, T.~D.; Bale, S.~D.; Whittlesey, P.~L.; Kasper, J.~C.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac408f Parker Data Used; 1491; 310; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
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The Turbulent Properties of the Sub-Alfv\ enic Solar Wind Measured by the Parker Solar Probe For the first time, Parker Solar Probe (PSP) observed the sub- Alfv\ enic solar wind where the solar wind bulk speed drops below the local Alfv\ en speed for an extended period of time. Here, we report on the turbulent properties of the sub- Alfv\ enic region. We analyze the turbulence correlation length and the energy transfer and compare the results with nearby super-Alfv\ enic regions. As the Alfv\ en speed is larger or comparable to the solar wind speed in the intervals studied, we use a modified Taylor s hypothesis to a ... Zhao, L.; Zank, G.~P.; Telloni, D.; Stevens, M.; Kasper, J.~C.; Bale, S.~D.; Published by: \apjl Published on: apr YEAR: 2022 DOI: 10.3847/2041-8213/ac5fb0 Parker Data Used; Solar wind; interplanetary turbulence; 1534; 830 |
