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Found 300 entries in the Bibliography.
Showing entries from 1 through 50
| 2021 |
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We present a major update to the 3D coronal rope ejection (3DCORE) technique for modeling coronal mass ejection flux ropes in conjunction with an approximate Bayesian computation (ABC) algorithm that is used for fitting the model to in situ magnetic field measurements. The model assumes an empirically motivated torus-like flux rope structure that expands self-similarly within the heliosphere, is influenced by a simplified interaction with the solar wind environment, and carries along an embedded analytical magnetic field. Th ... Weiss, Andreas; Moestl, Christian; Amerstorfer, Tanja; Bailey, Rachel; Reiss, Martin; Hinterreiter, Juergen; Amerstorfer, Ute; Bauer, Maike; Published by: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Published on: JAN YEAR: 2021 DOI: 10.3847/1538-4365/abc9bd |
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Parker Solar Probe observations of He/H abundance variations in SEP events inside 0.5 au Cohen, C.M.S.; Christian, E.R.; Cummings, A.C.; Davis, A.J.; Desai, M.I.; Giacalone, J.; Hill, M.E.; Joyce, C.J.; Labrador, A.W.; Leske, R.A.; Matthaeus, W.H.; McComas, D.J.; McNutt, R.L.; Mewaldt, R.A.; Mitchell, D.G.; Rankin, J.S.; Roelof, E.C.; al., et; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039299" |
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Switchbacks: Statistical properties and deviations from Alfv\ enicity Larosa, A.; Krasnoselskikh, V.; de Wit, Dudok; Agapitov, O.; Froment, C.; al., et; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039442" |
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Cattell, C.; Short, B.; Breneman, A.; Halekas, J.; Whittesley, P.; Larson, D.; Kasper, J.; Stevens, M.; Case, T.; ., al; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039550" |
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Solar wind energy flux observations in the inner heliosphere: First results from Parker Solar Probe Liu, M.; Issautier, K.; Meyer-Vernet, N.; Moncuquet, M.; Maksimovic, M.; Halekas, J.; Huang, J.; Griton, L.; Bale, S.; Bonnell, J.; Case, A.; Goetz, K.; Harvey, P.; Kasper, J.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Stevens, M.; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039615" |
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Wiedenbeck, M.; Burnham, J.; Cohen, C.; Cook, W.; Crabill, R.; Cummings, A.; Davis, A.; Kecman, B.; Labrador, A.; Leske, R.; Mewaldt, R.; Rankin, J.; Rusert, M.; Stone, E.; Christian, E.; Goodwin, P.; al., et; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039754" |
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Froment, C.; Krasnoselskikh, V.; de Wit, Dudok; Agapitov, O.; Fargette, N.; Lavraud, B.; Kretzschmar, M.; Jagarlamudi, V.; Larosa, A.; Velli, M.; Malaspina, D.; Bale, S.; Case, A.; Goetz, K.; Kasper, J.; Korreck, K.; Larson, D.; ., al; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039806" |
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Jagarlamudi, V.K.; de Wit, Dudok; Froment, C.; Krasnoselskikh, V.; Larosa, A.; Bercic, L.; Agapitov, O.; Halekas, J.S.; Kretzschmar, M.; Malaspina, D.; Moncuquet, M.; Bale, S.; Case, A.; Kasper, J.; Korreck, K.; Larson, D.; Pulupa, M.; Stevens, M.; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039808" |
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Chhiber, R.; Matthaeus, W.; Cohen, C.; Ruffolo, D.; Sonsrettee, W.; Tooprakai, P.; Seripienlert, A.; Chuychai, P.; Usmanov, A.; Goldstein, M.; McComas, D.; Leske, R.; Christian, E.; Mewaldt, R.; Labrador, A.; al., et; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039816" |
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Alfvenic versus non-Alfvenic turbulence in the inner heliosphere as observed by Parker Solar Probe Shi, C.; Velli, M.; Panasenco, O.; Tenerani, A.; eville, V.; Bale, S.; Kasper, J.; Korreck, K.; Bonnell, J.; de Wit, Dudok; Goetz, K.; Harvey, P.; MacDowall, R.; Pulupa, M.; Case, A.; Larson, D.; Verniero, J.; Livi, R.; Stevens, M.; al., et; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039818" |
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The near-Sun streamer belt solar wind: turbulence and solar wind acceleration Chen, C.; Chandran, B.; Woodham, L.; Jones, S.; Perez, J.; Bourouaine, S.; Bowen, T.; Klein, K.; Moncuquet, M.; Kasper, J.; Bale, S.; Published by: Astronomy and Astrophysics Published on: YEAR: 2021 DOI: "10.1051/0004-6361/202039872" |
| 2020 |
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DC and Low-Frequency Electric Field Measurements on the Parker Solar Probe The Parker Solar Probe successfully makes electric field measurements over the frequency range of DC-100 Hz, thanks to the remarkable symmetry of the antennas with respect to sunlight and the mostly radial magnetic field. Calibration of the electric field measurement is described. Sampled electric and magnetic field data are utilized to determine wave modes of whistlers and Alfven-ion-cyclotron waves. In the course of such determinations, the electric field effective antenna length was found to vary with frequency from simil ... Mozer, F.; Agapitov, O.; Bale, S.; Bonnell, J.; Bowen, T.; Vasko, I.; Published by: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS Published on: SEP YEAR: 2020 DOI: 10.1029/2020JA027980 |
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Trajectory Determination for Coronal Ejecta Observed by WISPR/Parker Solar Probe TheWide-field Imager for Solar Probe(WISPR) onboard theParker Solar Probe(PSP), observing in white light, has a fixed angular field of view, extending from 13.5(circle)to 108(circle)from the Sun and approximately 50(circle)in the transverse direction. Because of the highly elliptical orbit of PSP, the physical extent of the imaged coronal region varies directly as the distance from the Sun, requiring new techniques for analysis of the motions of observed density features. Here, we present a technique for determining the 3D t ... Liewer, P.; Qiu, J.; Penteado, P.; Hall, J.; Vourlidas, A.; Howard, R.; Published by: SOLAR PHYSICS Published on: OCT 22 YEAR: 2020 DOI: 10.1007/s11207-020-01715-y |
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Solar Wind Plasma Particles Organized by the Flow Speed Recent reports of the first data from Parker Solar Probe (PSP) have pointed to a series of links, correlations or anti-correlations between the solar wind bulk speed (VSW) and physical properties of plasma particles from less than 0.25 AU in the corona. In the present paper, we describe corresponding and additional links of solar wind properties, at 0.4 AU and 1.0 AU, in an attempt to complement the PSP data and understand their evolution. A detailed analysis is carried out for the main electron populations, comparing the lo ... Pierrard, Viviane; Lazar, Marian; Stverak, Stepan; Published by: SOLAR PHYSICS Published on: NOV 5 YEAR: 2020 DOI: 10.1007/s11207-020-01730-z |
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Proton core behaviour inside magnetic field switchbacks During Parker Solar Probe s first two orbits, there are widespread observations of rapid magnetic field reversals known as switchbacks. These switchbacks are extensively found in the near-Sun solar wind, appear to occur in patches, and have possible links to various phenomena such as magnetic reconnection near the solar surface. As switchbacks are associated with faster plasma flows, we questioned whether they are hotter than the background plasma and whether the microphysics inside a switchback is different to its surroundi ... Woolley, Thomas; Matteini, Lorenzo; Horbury, Timothy; Bale, Stuart; Woodham, Lloyd; Laker, Ronan; Alterman, Benjamin; Bonnell, John; Case, Anthony; Kasper, Justin; Klein, Kristopher; Martinovic, Mihailo; Stevens, Michael; Published by: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Published on: NOV YEAR: 2020 DOI: 10.1093/mnras/staa2770 |
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Reconnection between pairs of solar magnetic flux elements, one open and the other a closed loop, is theorized to be a crucial process for both maintaining the structure of the corona and producing the solar wind. This interchange reconnection is expected to be particularly active at the open-closed boundaries of coronal holes (CHs). Previous analysis of solar wind data at 1 au indicated that peaks in the flux of suprathermal electrons at slow-fast stream interfaces may arise from magnetic connection to the CH boundary, ra ... MacNeil, Allan; Owens, Mathew; Bercic, Laura; Finley, Adam; Published by: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Published on: NOV YEAR: 2020 DOI: 10.1093/mnras/staa2660 |
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Small-scale Magnetic Flux Ropes in the First Two Parker Solar Probe Encounters Small-scale magnetic flux ropes (SFRs) are a type of structure in the solar wind that possess helical magnetic field lines. In a recent report we presented the radial variations of the properties of SFRs from 0.29 to 8 au using in situ measurements from the Helios, Advanced Composition Explorer/WIND (ACE/Wind), Ulysses, and Voyager spacecrafts. With the launch of the Parker Solar Probe (PSP), we extend our previous investigation further into the inner heliosphere. We apply a Grad-Shafranov-based algorithm to identify SFRs du ... Chen, Yu; Hu, Qiang; Zhao, Lingling; Kasper, Justin; Bale, Stuart; Korreck, Kelly; Case, Anthony; Stevens, Michael; Bonnell, John; Goetz, Keith; Harvey, Peter; Klein, Kristopher; Larson, Davin; Livi, Roberto; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Whittlesey, Phyllis; Published by: ASTROPHYSICAL JOURNAL Published on: NOV YEAR: 2020 DOI: 10.3847/1538-4357/abb820 |
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Two-time energy spectrum of weak magnetohydrodynamic turbulence In this work a weak-turbulence closure is used to determine the structure of the two-time power spectrum of weak magnetohydrodynamic (MHD) turbulence from the nonlinear equations describing the dynamics. The two-time energy spectrum is a fundamental quantity in turbulence theory from which most statistical properties of a homogeneous turbulent system can be derived. A closely related quantity, obtained via a spatial Fourier transform, is the two-point two-time correlation function describing the space-time correlations arisi ... Perez, Jean; Azelis, Augustus; Bourouaine, Sofiane; Published by: PHYSICAL REVIEW RESEARCH Published on: MAY 19 YEAR: 2020 DOI: 10.1103/PhysRevResearch.2.023189 |
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Nine Outstanding Questions of Solar Wind Physics In situ measurements of the solar wind have been available for almost 60 years, and in that time plasma physics simulation capabilities have commenced and ground-based solar observations have expanded into space-based solar observations. These observations and simulations have yielded an increasingly improved knowledge of fundamental physics and have delivered a remarkable understanding of the solar wind and its complexity. Yet there are longstanding major unsolved questions. Synthesizing inputs from the solar wind research ... Viall, Nicholeen; Borovsky, Joseph; Published by: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS Published on: JUL YEAR: 2020 DOI: 10.1029/2018JA026005 |
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On August 12, 2018, NASA launched the Parker Solar Probe (PSP) to explore regions very near the Sun. Losing enough energy and angular momentum to approach the Sun requires either an impractical amount of fuel or a maneuver called a gravity assist. A gravity assist is essentially an elastic collision with a massive, moving target-Rutherford scattering from a planet. Gravity assists are often used to gain energy in missions destined for the outer solar system, but they can also be used to lose energy. Reaching an orbit suffici ... Published by: AMERICAN JOURNAL OF PHYSICS Published on: JAN YEAR: 2020 DOI: 10.1119/10.0000145 |
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Modeling the Early Evolution of a Slow Coronal Mass Ejection Imaged by the Parker Solar Probe During its first solar encounter, the Parker Solar Probe (PSP) acquired unprecedented up-close imaging of a small coronal mass ejection (CME) propagating in the forming slow solar wind. The CME originated as a cavity imaged in extreme ultraviolet that moved very slowly (<50 km s(-1)) to 3-5 solar radii (R), where it then accelerated to supersonic speeds. We present a new model of an erupting flux rope (FR) that computes the forces acting on its expansion with a computation of its internal magnetic field in three dimensions. ... Rouillard, Alexis; Poirier, Nicolas; Lavarra, Michael; Bourdelle, Anthony; Dalmasse, Kevin; Kouloumvakos, Athanasios; Vourlidas, Angelos; Kunkel, Valbona; Hess, Phillip; Howard, Russ; Stenborg, Guillermo; Raouafi, Nour; Published by: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Published on: FEB YEAR: 2020 DOI: 10.3847/1538-4365/ab6610 |
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Operational Modeling of Heliospheric Space Weather for the Parker Solar Probe The interpretation of multi-spacecraft heliospheric observations and three-dimensional reconstruction of the structured and evolving solar wind with propagating and interacting coronal mass ejections (CMEs) is a challenging task. Numerical simulations can provide global context and suggest what may and may not be observed. The Community Coordinated Modeling Center (CCMC) provides both mission science and space weather support to all heliospheric missions. Currently, this is realized by real-time simulations of the corotating ... Odstrcil, Dusan; Mays, Leila; Hess, Phillip; Jones, Shaela; Henney, Carl; Arge, Charles; Published by: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Published on: FEB YEAR: 2020 DOI: 10.3847/1538-4365/ab77cb |
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MHD Mode Composition in the Inner Heliosphere from the Parker Solar Probe s First Perihelion Field and plasma variations during the first perihelion pass of the Parker Solar Probe (PSP) from 53 into 35 solar radii (R-S) from the Sun and over a frequency range in the spacecraft frame (f(SC)) from 0.0002 to 0.2 Hz are decomposed into constituent magnetohydrodynamic (MHD) modes. The analysis operates on measurements of the MHD variables recorded between impulsive, large amplitude rotations of the magnetic field to reveal the dominance of a broad spectrum of shear Alfven waves propagating antiparallel (backward) to the ... Chaston, C.; Bonnell, J.; Bale, S.; Kasper, J.; Pulupa, M.; de Wit, Dudok; Bowen, T.; Larson, D.; Whittlesey, P.; Wygant, J.; Salem, C.; MacDowall, R.; Livi, R.; Vech, D.; Case, A.; Stevens, M.; Korreck, K.; Goetz, K.; Harvey, P.; Malaspina, D.; Published by: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Published on: FEB YEAR: 2020 DOI: 10.3847/1538-4365/ab745c |
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We present a technique for deriving the temperature anisotropy of solar wind protons observed by the Parker Solar Probe (PSP) mission in the near-Sun solar wind. The radial proton temperature measured by the Solar Wind Electrons, Alphas, and Protons (SWEAP) Solar Probe Cup is compared with the orientation of local magnetic field measured by the FIELDS fluxgate magnetometer, and the proton temperatures parallel and perpendicular to the magnetic field are extracted. This procedure is applied to different data products, and the ... Huang, Jia; Kasper, J.; Vech, D.; Klein, K.; Stevens, M.; Martinovic, Mihailo; Alterman, B.; Durovcova, Tereza; Paulson, Kristoff; Maruca, Bennett; Qudsi, Ramiz; Case, A.; Korreck, K.; Jian, Lan; Velli, Marco; Lavraud, B.; Hegedus, A.; Bert, C.; Holmes, J.; Bale, Stuart; Larson, Davin; Livi, Roberto; Whittlesey, P.; Pulupa, Marc; MacDowall, Robert; Malaspina, David; Bonnell, John; Harvey, Peter; Goetz, Keith; de Wit, Thierry; Published by: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Published on: FEB YEAR: 2020 DOI: 10.3847/1538-4365/ab74e0 |
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Seed Population Preconditioning and Acceleration Observed by the Parker Solar Probe A series of solar energetic particle (SEP) events was observed by the Integrated Science Investigation of the Sun (ISeIS) on the Parker Solar Probe (PSP) during the period from 2019 April 18 through 24. The PSP spacecraft was located near 0.48 au from the Sun on Parker spiral field lines that projected out to 1 au within similar to 25 degrees of the near-Earth spacecraft. These SEP events, though small compared to historically large SEP events, were among the largest observed thus far in the PSP mission and provide critical ... Schwadron, N.; Bale, S.; Bonnell, J.; Case, A.; Christian, E.; Cohen, C.; Cummings, A.; Davis, A.; de Wit, Dudok; de Wet, W.; Desai, M.; Joyce, C.; Goetz, K.; Giacalone, J.; Gorby, M.; Harvey, P.; Heber, B.; Hill, M.; Karavolos, M.; Kasper, J.; Korreck, K.; Larson, D.; Livi, R.; Leske, R.; Malandraki, O.; MacDowall, R.; Malaspina, D.; Matthaeus, W.; McComas, D.; McNutt, R.; Mewaldt, R.; Mitchell, D.; Mays, L.; Niehof, J.; Odstrcil, D.; Pulupa, M.; Poduval, B.; Rankin, J.; Roelof, E.; Stevens, M.; Stone, E.; Szalay, J.; Wiedenbeck, M.; Winslow, R.; Whittlesey, P.; Published by: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Published on: FEB YEAR: 2020 DOI: 10.3847/1538-4365/ab5527 |
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Turbulence Characteristics of Switchback and Nonswitchback Intervals Observed by Parker Solar Probe We use Parker Solar Probe (PSP) in situ measurements to analyze the characteristics of solar wind turbulence during the first solar encounter covering radial distances between 35.7R and 41.7R. In our analysis we isolate so-called switchback (SB) intervals (folded magnetic field lines) from nonswitchback (NSB) intervals, which mainly follow the Parker spiral field. Using a technique based on conditioned correlation functions, we estimate the power spectra of Elsasser, magnetic, and bulk velocity fields separately in the SB an ... Bourouaine, Sofiane; Perez, Jean; Klein, Kristopher; Chen, Christopher; Martinovic, Mihailo; Bale, Stuart; Kasper, Justin; Raouafi, Nour; Published by: ASTROPHYSICAL JOURNAL LETTERS Published on: DEC YEAR: 2020 DOI: 10.3847/2041-8213/abbd4a |
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Radio Signature of a Distant behind-the-limb CME on 2017 September 6 We discuss properties of a Type IV burst, which was observed on 2017 September 6, as a result of the powerful flare X 9.3. At decameter wavelengths this burst was observed by the radio telescopes STEREO A, URAN-2, and the Nancay Decameter Array at frequencies 5-35 MHz. This moving Type IV burst was associated with a coronal mass ejection (CME) propagating in the southwest direction with a speed of 1570 km s(-1). The maximum radio flux of this burst was about 300 s.f.u. and the polarization was more than 40\%. In the frequenc ... Melnik, V.; Rucker, H.; Brazhenko, I.; Panchenko, M.; Konovalenko, A.; , Frantsuzenko; Dorovskyy, V.; , Shevchuk; Published by: ASTROPHYSICAL JOURNAL Published on: DEC YEAR: 2020 DOI: 10.3847/1538-4357/abbfb3 |
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The Parker Solar Probe mission has shown the ubiquitous presence of strong magnetic field deflections, namely switchbacks, during its first perihelion where it was embedded in a highly Alfvenic slow stream. Here, we study the turbulent magnetic fluctuations around ion scales in three intervals characterized by a different switchback activity, identified by the behavior of the magnetic field radial component, B-r. Quiet (B-r does not show significant fluctuations), weakly disturbed (B-r has strong fluctuations but no reversal ... Perrone, Denise; Bruno, Roberto; Amicis, Raffaella; Telloni, Daniele; De Marco, Rossana; Stangalini, Marco; Perri, Silvia; Pezzi, Oreste; Alexandrova, Olga; Bale, Stuart; Published by: ASTROPHYSICAL JOURNAL Published on: DEC YEAR: 2020 DOI: 10.3847/1538-4357/abc480 |
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Dust sputtering within the inner heliosphere: a modelling study The aim of this study is to investigate through modelling how sputtering by impacting solar wind ions influences the lifetime of dust particles in the inner heliosphere near the Sun. We consider three typical dust materials, silicate, Fe0.4Mg0.6O, and carbon, and describe their sputtering yields based on atomic yields given by the Stopping and Range of Ions in Matter (SRIM) package. The influence of the solar wind is characterized by plasma density, solar wind speed, and solar wind composition, and we assume for these parame ... Baumann, Carsten; Myrvang, Margaretha; Mann, Ingrid; Published by: ANNALES GEOPHYSICAE Published on: AUG 3 YEAR: 2020 DOI: 10.5194/angeo-38-919-2020 |
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Energy Supply for Heating the Slow Solar Wind Observed by Parker Solar Probe between 0.17 and 0.7 au Energy supply sources for the heating process in the slow solar wind remain unknown. The Parker Solar Probe (PSP) mission provides a good opportunity to study this issue. Recently, PSP observations have found that the slow solar wind experiences stronger heating inside 0.24 au. Here for the first time we measure in the slow solar wind the radial gradient of the low-frequency breaks on the magnetic trace power spectra and evaluate the associated energy supply rate. We find that the energy supply rate is consistent with the ob ... Wu, Honghong; Tu, Chuanyi; Wang, Xin; He, Jiansen; Yang, Liping; Published by: The Astrophysical Journal Published on: 11/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abc5b6 Parker data used; Slow solar wind; Interplanetary turbulence; Solar coronal heating |
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The Parker Solar Probe (PSP) and Solar Orbiter missions are designed to make groundbreaking observations of the Sun and interplanetary space within this decade. We show that a particularly interesting in situ observation of an interplanetary coronal mass ejection (ICME) by PSP may arise during close solar flybys (<0.1 au). During these times, the same magnetic flux rope inside an ICME could be observed in situ by PSP twice, by impacting its frontal part as well as its leg. Investigating the odds of this situation, we forecas ... Möstl, Christian; Weiss, Andreas; Bailey, Rachel; Reiss, Martin; Amerstorfer, Tanja; Hinterreiter, Jürgen; Bauer, Maike; McIntosh, Scott; Lugaz, No\; Stansby, David; Published by: The Astrophysical Journal Published on: 11/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb9a1 |
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We present results of a two-dimensional fully kinetic particle-in-cell simulation in order to shed light on the role of whistler waves in the scattering of strahl electrons and in the heat-flux regulation in the solar wind. We model the electron velocity distribution function as initially composed of core and strahl populations as typically encountered in the near-Sun solar wind as observed by Parker Solar Probe. We demonstrate that, as a consequence of the evolution of the electron velocity distribution function (VDF), two ... Micera, A.; Zhukov, A.; opez, R.; Innocenti, M.; Lazar, M.; Boella, E.; Lapenta, G.; Published by: The Astrophysical Journal Published on: 11/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abc0e8 parker Data Used; Solar wind; Space plasmas; Plasma astrophysics |
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Shear-driven Transition to Isotropically Turbulent Solar Wind Outside the Alfv\ en Critical Zone Motivated by prior remote observations of a transition from striated\ solar\ coronal structures to more isotropic "flocculated" fluctuations, we propose that the dynamics of the inner\ solar\ wind just outside the Alfven critical zone, and in the vicinity of the first beta = 1 surface, is powered by the relative velocities of adjacent coronal magnetic flux tubes. We suggest that large-amplitude flow contrasts are magnetically constrained at lower altitude but shear-driven dynamics are triggered as such ... Ruffolo, D.; Matthaeus, W.; Chhiber, R.; Usmanov, A.; Yang, Y.; Bandyopadhyay, R.; Parashar, T.; Goldstein, M.; DeForest, C.; Wan, M.; Chasapis, A.; Maruca, B.; Velli, M.; Kasper, J.; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb594 |
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Small Electron Events Observed by Parker Solar Probe/IS⊙IS during Encounter 2 The current understanding of the characteristics of\ solar\ and inner heliospheric electron events is inferred almost entirely from observations made by spacecraft located at 1 astronomical unit (au). Previous observations within 1 au of the Sun, by the Helios spacecraft at similar to 0.3-1 au, indicate the presence of electron events that are not detected at 1 au or may have merged during transport from the Sun.\ Parker\ Solar\ Probe\textquoterights close proximity to the Sun at perihelion provid ... Mitchell, J.; de Nolfo, G.; Hill, M.; Christian, E.; McComas, D.; Schwadron, N.; Wiedenbeck, M.; Bale, S.; Case, A.; Cohen, C.; Joyce, C.; Kasper, J.; Labrador, A.; Leske, R.; MacDowall, R.; Mewaldt, R.; Mitchell, D.; Pulupa, M.; Richardson, I.; Stevens, M.; Szalay, J.; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb2a4 Parker Data Used; parker solar probe; Radio bursts; Solar energetic particles; solar flares; Solar particle emission; Solar Physics; Solar Probe Plus |
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We propose a turbulence-driven\ solar\ wind model for a fast\ solar\ wind flow in an open coronal hole where the\ solar\ wind flow and the magnetic field are highly aligned. We compare the numerical results of our model with\ Parker\ Solar\ Probe\ measurements of the fast\ solar\ wind flow and find good agreement between them. We find that (1) the majority quasi-2D turbulence is mainly responsible for coronal heating, raising the temperature to about similar to 1 ... Adhikari, L.; Zank, G.; Zhao, L.-L.; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb132 |
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The Solar Wind Angular Momentum Flux as Observed by Parker Solar Probe he long-term evolution of the Sun\textquoterights rotation period cannot be directly observed, and is instead inferred from trends in the measured rotation periods of other Sun-like stars. Assuming the Sun spins down as it ages, following rotation rate proportional to age(-1/2), requires the current\ solar\ angular momentum (AM) loss rate to be around 6 x 10(30)erg. Magnetohydrodynamic models, and previous observations of the\ solar\ wind (from the Helios and Wind spacecraft), generally predict a value ... Finley, Adam; Matt, Sean; eville, Victor; Pinto, Rui; Owens, Mathew; Kasper, Justin; Korreck, Kelly; Case, A.; Stevens, Michael; Whittlesey, Phyllis; Larson, Davin; Livi, Roberto; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abb9a5 Parker Data Used; parker solar probe; Solar evolution; Solar Physics; Solar Probe Plus; Solar rotation; Solar wind; Stellar evolution; Stellar physics; Stellar rotation |
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The Origin of Switchbacks in the Solar Corona: Linear Theory The origin, structure, and propagation characteristics of a switchback are compelling questions posed by Parker Solar Probe (PSP) observations of velocity spikes and magnetic field reversals. By assuming interchange reconnection between coronal loop and open magnetic field, we show that this results in the generation of upward (into the heliosphere) and downward complex structures propagating at the fast magnetosonic speed (i.e., the Alfvén speed in the low plasma beta corona) that can have an arbitrary radial magnetic fiel ... Zank, G.; Nakanotani, M.; Zhao, L.-L.; Adhikari, L.; Kasper, J.; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb828 Parker Data Used ; Active Solar Corona; Solar Coronal Waves; Interplanetary Turbulence; |
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Large-amplitude, Wideband, Doppler-shifted, Ion Acoustic Waves Observed on the Parker Solar Probe Electric field spectra measured on the\ Parker\ Solar\ Probe\ typically contain upwards of 1000 large-amplitude (similar to 15 mV m(-1)), wideband (similar to 100-15,000 Hz), few-second-duration, electric field waveforms per day. The satellite also collected about 85 three-second bursts of electric field waveforms per day at a data rate of similar to 150,000 samples per second. Eight such bursts caught these waves, all of which were located in switchbacks of the magnetic field. A wave burst on 2019 Sep ... Mozer, F.; Bonnell, J.; Bowen, T.; Schumm, G.; . Y. Vasko, I; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abafb4 Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind |
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On the Scaling Properties of Magnetic-field Fluctuations through the Inner Heliosphere Although the interplanetary magnetic-field variability has been extensively investigated in situ using data from several space missions, newly launched missions providing high-resolution measures and approaching the Sun offer the possibility to study the multiscale variability in the innermost\ solar\ system. Here, using\ Parker\ Solar\ Probe\ measurements, we investigate the scaling properties of\ solar\ wind magnetic-field fluctuations at different heliocentric distances. The resu ... Alberti, Tommaso; Laurenza, Monica; Consolini, Giuseppe; Milillo, Anna; Marcucci, Maria; Carbone, Vincenzo; Bale, Stuart; Published by: The Astrophysical Journal Published on: 10/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abb3d2 Chaos; interplanetary magnetic fields; interplanetary turbulence; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Time series analysis |
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Context. The launch of\ Parker\ Solar\ Probe\ (PSP) in 2018, followed by\ Solar\ Orbiter (SO) in February 2020, has opened a new window in the exploration of\ solar\ magnetic activity and the origin of the heliosphere. These missions, together with other space observatories dedicated to\ solar\ observations, such as the\ Solar\ Dynamics Observatory, Hinode, IRIS, STEREO, and SOHO, with complementary in situ observations from WIND and ACE, and ground based multi-w ... Velli, M.; Harra, L.; Vourlidas, A.; Schwadron, N.; Panasenco, O.; Liewer, P.; Müller, D.; Zouganelis, I.; St Cyr, O.; Gilbert, H.; Nieves-Chinchilla, T.; Auchère, F.; Berghmans, D.; Fludra, A.; Horbury, T.; Howard, R.; Krucker, S.; Maksimovic, M.; Owen, C.; iguez-Pacheco, Rodr\; Romoli, M.; Solanki, S.; Wimmer-Schweingruber, R.; Bale, S.; Kasper, J.; McComas, D.; Raouafi, N.; Martinez-Pillet, V.; Walsh, A.; De Groof, A.; Williams, D.; Published by: Astronomy \& Astrophysics Published on: 09/2020 YEAR: 2020 DOI: 10.1051/0004-6361/202038245 Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; solar-terrestrial relations; Sun: atmosphere; Sun: corona; Sun: heliosphere; Sun: magnetic fields |
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Turbulence, a ubiquitous phenomenon in interplanetary space, is crucial for the energy conversion of space plasma at multiple scales. This work focuses on the propagation, polarization, and wave composition properties of the\ solar\ wind turbulence within 0.3 au, and its variation with heliocentric distance at magnetohydrodynamic scales (from 10 s to 1000 s in the spacecraft frame). We present the probability density function of propagation wavevectors (PDF (k(parallel to),k)) for\ solar\ wind turbulen ... Zhu, Xingyu; He, Jiansen; Verscharen, Daniel; Duan, Die; Bale, Stuart; Published by: The Astrophysical Journal Published on: 09/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abb23e Alfv\ en waves; Heliosphere; interplanetary turbulence; Parker Data Used; parker solar probe; Slow solar wind; Solar Probe Plus |
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Analysis of the Helical Kink Stability of Differently Twisted Magnetic Flux Ropes Magnetic flux ropes (MFRs) are usually considered to be the magnetic structure that dominates the transport of helicity from the Sun into the heliosphere. They entrain a confined plasma within a helically organized magnetic structure and are able to cause geomagnetic activity. The formation, evolution, and twist distribution of MFRs are issues subject to strong debate. Although different twist profiles have been suggested so far, none of them has been thoroughly explored yet. The aim of this work is to present a theoretic ... Florido-Llinas, M.; Nieves-Chinchilla, T.; Linton, M.; Published by: Solar Physics Published on: 09/2020 YEAR: 2020 DOI: 10.1007/s11207-020-01687-z coronal mass ejections; Flux ropes; Kink instability; magnetic fields; parker solar probe; Solar Probe Plus; Twist distribution |
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Cross Helicity of the 2018 November Magnetic Cloud Observed by the Parker Solar Probe Magnetic clouds are large-scale transient structures in the solar wind with low plasma-beta, low-amplitude magnetic field fluctuations, and twisted field lines with both ends often connected to the Sun. Their inertial-range turbulent properties have not been examined in detail. In this Letter, we analyze the normalized cross helicity, sigma(c), and residual energy, sigma(r), of plasma fluctuations in the 2018 November magnetic cloud observed at 0.25.au by the Parker Solar Probe. A low value of |sigma(c)| was present in th ... Good, S.; Kilpua, E.; Ala-Lahti, M.; Osmane, A.; Bale, S.; Zhao, L.-L.; Published by: The Astrophysical Journal Published on: 09/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abb021 interplanetary magnetic fields; interplanetary turbulence; Parker Data Used; parker solar probe; Solar coronal mass ejections; Solar Probe Plus; Solar wind |
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Microinstabilities and waves excited at moderate-Mach-number perpendicular shocks in the near-Sun solar wind are investigated by full particle-in-cell simulations. By analyzing the dispersion relation of fluctuating field components directly issued from the shock simulation, we obtain key findings concerning wave excitations at the shock front: (1) at the leading edge of the foot, two types of electrostatic (ES) waves are observed. The relative drift of the reflected ions versus the electrons triggers an electron cyclotro ... Yang, Zhongwei; Liu, Ying; Matsukiyo, Shuichi; Lu, Quanming; Guo, Fan; Liu, Mingzhe; Xie, Huasheng; Gao, Xinliang; Guo, Jun; Published by: The Astrophysical Journal Published on: 09/2020 YEAR: 2020 DOI: 10.3847/2041-8213/abaf59 Interplanetary shocks; parker solar probe; Plasma astrophysics; Plasma physics; Solar Probe Plus; Space plasmas |
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Polytropic Behavior of Solar Wind Protons Observed by Parker Solar Probe A polytropic process describes the transition of a fluid from one state to another through a specific relationship between the fluid density and temperature. The value of the polytropic index that governs this relationship determines the heat transfer and the effective degrees of freedom during a specific process. In this study, we analyze\ solar\ wind proton plasma measurements, obtained by the Faraday cup instrument on board the\ Parker\ Solar\ Probe. We examine the large-scale variations of the ... Nicolaou, Georgios; Livadiotis, George; Wicks, Robert; Verscharen, Daniel; Maruca, Bennett; Published by: The Astrophysical Journal Published on: 09/2020 YEAR: 2020 DOI: 10.3847/1538-4357/abaaae Parker Data Used; parker solar probe; Solar Physics; Solar Probe Plus; Solar wind; Space plasmas |
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The Solar Origin of Particle Events Measured by Parker Solar Probe During the second solar encounter phase of Parker Solar Probe (PSP), two small solar energetic particle (SEP) events were observed by the Integrated Science Investigation of the Sun, on 2019 April 2 and 4. At the time, PSP was approaching its second perihelion at a distance of \~24.8 million kilometers from the solar center, it was in near-radial alignment with STEREO-A and in quadrature with Earth. During the two SEP events multiple narrow ejections and a streamer-blowout coronal mass ejection (SBO-CME) originated from a ... Kouloumvakos, Athanasios; Vourlidas, Angelos; Rouillard, Alexis; Roelof, Edmond; Leske, Rick; Pinto, Rui; Poirier, Nicolas; Published by: The Astrophysical Journal Published on: 08/2020 YEAR: 2020 DOI: 10.3847/1538-4357/aba5a1 Parker Data Used; parker solar probe; Solar coronal mass ejection shocks; Solar coronal mass ejections; Solar energetic particles; Solar particle emission; Solar Probe Plus |
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Spectral Features in Field-aligned Solar Wind Turbulence from Parker Solar Probe Observations Parker Solar Probe (PSP) observed a large variety of Alfv\ enic fluctuations in the fast and slow solar wind flow during its two perihelia. The properties of Alfv\ enic solar wind turbulence have been studied for decades in the near-Earth environment. A spectral index of -5/3 or -2 for magnetic field fluctuations has been observed using spacecraft measurements, which can be explained by turbulence theories of nearly incompressible magnetohydrodynamics (NI MHD) or critical balance. In this study, a rigorous search of field ... Zhao, L.-L.; Zank, G.; Adhikari, L.; Nakanotani, M.; Telloni, D.; Carbone, F.; Published by: The Astrophysical Journal Published on: 08/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab9b7e interplanetary turbulence; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Spectral index |
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The Electromagnetic Signature of Outward Propagating Ion-scale Waves First results from the Parker Solar Probe (PSP) mission have revealed ubiquitous coherent ion-scale waves in the inner heliosphere, which are signatures of kinetic wave-particle interactions and fluid instabilities. However, initial studies of the circularly polarized ion-scale waves observed by PSP have only thoroughly analyzed magnetic field signatures, precluding a determination of solar wind frame propagation direction and intrinsic wave polarization. A comprehensive determination of wave properties requires measureme ... Bowen, Trevor; Bale, Stuart; Bonnell, J.; Larson, Davin; Mallet, Alfred; McManus, Michael; Mozer, Forrest; Pulupa, Marc; Vasko, Ivan; Verniero, J.; Published by: The Astrophysical Journal Published on: 08/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab9f37 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar Probe Plus; Solar wind; Space plasmas |
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Magnetic Field Dropouts at Near-Sun Switchback Boundaries: A Superposed Epoch Analysis During Parker Solar Probe\textquoterights first close encounter with the Sun in early 2018 November, a large number of impulsive rotations in the magnetic field were detected within 50 Rs; these also occurred in association with short-lived impulsive solar wind bursts in speed. These impulsive features are now called "switchback" events. We examined a set of these switchbacks where the boundary transition into and out of the switchback was abrupt, with fast B rotations and simultaneous solar wind speed changes ... Farrell, W.; MacDowall, R.; Gruesbeck, J.; Bale, S.; Kasper, J.; Published by: The Astrophysical Journal Supplement Series Published on: 08/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab9eba Parker Data Used; parker solar probe; Solar Physics; Solar Probe Plus; Solar wind; The Sun |
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On the Shape of SEP Electron Spectra: The Role of Interplanetary Transport We address the effect of particle scattering on the energy spectra of solar energetic electron events using (I) an observational and (II) a modeling approach. (I) We statistically study observations of the STEREO spacecraft, using directional electron measurements made with the Solar Electron and Proton Telescope in the range of 45-425 keV. We compare the energy spectra of the anti-Sunward propagating beam with that of the backward-scattered population and find that, on average, the backward-scattered population shows a h ... Strauss, R.; Dresing, N.; Kollhoff, A.; Brüdern, M.; Published by: The Astrophysical Journal Published on: 07/2020 YEAR: 2020 DOI: 10.3847/1538-4357/ab91b0 |
