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Found 69 entries in the Bibliography.
Showing entries from 1 through 50
2023 |
Small-scale EUV features as the drivers of coronal upflows in the quiet Sun Context. Coronal upflows in the quiet Sun are seen in a wide range of features, including jets and filament eruptions. The in situ measurements from Parker Solar Probe within \ensuremath\approx0.2 au have demonstrated that the solar wind is highly structured, showing abrupt and near-ubiquitous magnetic field reversals (i.e., switchbacks) on different timescales. The source of these structures has been associated with supergranular structures on the solar disc. This raises the question of whether there are additional small co ... Schwanitz, Conrad; Harra, Louise; Mandrini, Cristina; Sterling, Alphonse; Raouafi, Nour; Cormack, Cecilia; Berghmans, David; Auchère, Fr\; Barczynski, Krzysztof; Cuadrado, Regina; Buchlin, Eric; Kraaikamp, Emil; Long, David; Parenti, Susanna; Peter, Hardi; Rodriguez, Luciano; Schühle, Udo; Smith, Phil; Teriaca, Luca; Verbeeck, Cis; Zhukov, Andrei; Published by: \aap Published on: jun YEAR: 2023   DOI: 10.1051/0004-6361/202346036 Parker Data Used; Sun: corona; Solar wind; Sun: UV radiation |
\ Aims: We applied the quasi-thermal noise (QTN) method to Parker Solar Probe (PSP) observations to derive the total electron temperature (T$_e$). We combined a set of encounters to make up a 12-day period of observations around each perihelion from encounter one (E01) to ten (E10), with E08 not included. Here, the heliocentric distance varies from about 13 to 60 solar radii (R$_\ensuremath\odot$). \ Methods: The QTN technique is a reliable tool to yield accurate measurements of the electron parameters in the solar wind. We ... Liu, M.; Issautier, K.; Moncuquet, M.; Meyer-Vernet, N.; Maksimovic, M.; Huang, J.; Martinovic, M.~M.; Griton, L.; Chrysaphi, N.; Jagarlamudi, V.~K.; Bale, S.~D.; Pulupa, M.; Kasper, J.~C.; Stevens, M.~L.; Published by: \aap Published on: jun YEAR: 2023   DOI: 10.1051/0004-6361/202245450 Parker Data Used; Solar wind; Sun: heliosphere; Sun: corona; methods: data analysis; plasmas; acceleration of particles; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
Interchange reconnection dynamics in a solar coronal pseudo-streamer Context. The generation of the slow solar wind remains an open problem in heliophysics. One of the current theories among those aimed at explaining the injection of coronal plasma in the interplanetary medium is based on interchange reconnection. It assumes that the exchange of magnetic connectivity between closed and open fields allows the injection of coronal plasma in the interplanetary medium to travel along the newly reconnected open field. However, the exact mechanism underlying this effect is still poorly understood. ... Pellegrin-Frachon, T.; Masson, S.; Pariat, \; Wyper, P.~F.; DeVore, C.~R.; Published by: \aap Published on: jul YEAR: 2023   DOI: 10.1051/0004-6361/202245611 Parker Data Used; magnetic fields; Sun: corona; magnetohydrodynamics (MHD); magnetic reconnection; Solar wind |
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 |
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 |
Identifying the energy release site in a solar microflare with a jet Context. One of the main science questions of the Solar Orbiter and Parker Solar Probe missions deals with understanding how electrons in the lower solar corona are accelerated and how they subsequently access interplanetary space. \ Aims: We aim to investigate the electron acceleration and energy release sites as well as the manner in which accelerated electrons access the interplanetary space in the case of the SOL2021-02-18T18:05 event, a GOES A8 class microflare associated with a coronal jet. \ Methods: This study takes ... Battaglia, Andrea; Wang, Wen; Saqri, Jonas; Podladchikova, Tatiana; Veronig, Astrid; Collier, Hannah; Dickson, Ewan; Podladchikova, Olena; Monstein, Christian; Warmuth, Alexander; Schuller, Fr\; Harra, Louise; Krucker, Säm; Published by: \aap Published on: feb YEAR: 2023   DOI: 10.1051/0004-6361/202244996 Parker Data Used; Sun: flares; Sun: corona; Sun: X-rays; gamma rays; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
2022 |
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 |
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 |
Context. Magnetic switchbacks in the solar wind are large deflections of the magnetic field vector, which often reverse their radial component, and are associated with a velocity spike consistent with their Alfv\ enic nature. The Parker Solar Probe (PSP) mission revealed them to be a dominant feature of the near-Sun solar wind. Where and how they are formed remains unclear and subject to discussion. \ Aims: We investigate the orientation of the magnetic field deflections in switchbacks to determine if they are characterized ... Fargette, Na; Lavraud, Benoit; Rouillard, Alexis; eville, Victor; Bale, Stuart; Kasper, Justin; Published by: \aap Published on: jul YEAR: 2022   DOI: 10.1051/0004-6361/202243537 Parker Data Used; Solar wind; Sun: magnetic fields; Sun: corona; Sun: photosphere; methods: data analysis; methods: statistical; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
An\ alisis cinem\ atico de una eyecci\ on coronal de masa de 10 a 46 radios solares Di Lorenzo, L.; Balmaceda, L.~A.; Cremades, H.; Published by: Boletin de la Asociacion Argentina de Astronomia La Plata Argentina Published on: jul Parker Data Used; Sun: coronal mass ejections (CMEs); Sun: corona; Sun: heliosphere; solar-terrestrial relations |
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 |
As a key feature, NASA s Parker Solar Probe (PSP) and ESA-NASA s Solar Orbiter (SO) missions cooperate to trace solar wind and transients from their sources on the Sun to the inner interplanetary space. The goal of this work is to accurately reconstruct the interplanetary Parker spiral and the connection between coronal features observed remotely by the Metis coronagraph on-board SO and those detected in situ by PSP at the time of the first PSP-SO quadrature of January 2021. We use the Reverse in situ and MHD Approach (RIMAP ... Biondo, Ruggero; Bemporad, Alessandro; Pagano, Paolo; Telloni, Daniele; Reale, Fabio; Romoli, Marco; Andretta, Vincenzo; Antonucci, Ester; Da Deppo, Vania; De Leo, Yara; Fineschi, Silvano; Heinzel, Petr; Moses, Daniel; Naletto, Giampiero; Nicolini, Gianalfredo; Spadaro, Daniele; Stangalini, Marco; Teriaca, Luca; Landini, Federico; Sasso, Clementina; Susino, Roberto; Jerse, Giovanna; Uslenghi, Michela; Pancrazzi, Maurizio; Published by: \aap Published on: dec YEAR: 2022   DOI: 10.1051/0004-6361/202244535 Parker Data Used; magnetohydrodynamics (MHD); methods: numerical; Solar wind; Sun: heliosphere; Sun: corona; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
2021 |
Context. In situ measurements by several spacecraft have revealed that the solar wind is frequently perturbed by transient structures that have been interpreted as magnetic folds, jets, waves, and flux ropes that propagate rapidly away from the Sun over a large range of heliocentric distances. Parker Solar Probe (PSP), in particular, has detected very frequent rotations of the magnetic field vector at small heliocentric radial distances, accompanied by surprisingly large solar wind rotation rates. The physical origin of such ... Pinto, R.~F.; Poirier, N.; Rouillard, A.~P.; Kouloumvakos, A.; Griton, L.; Fargette, N.; Kieokaew, R.; Lavraud, B.; Brun, A.~S.; Published by: \aap Published on: sep YEAR: 2021   DOI: 10.1051/0004-6361/202040180 Sun: corona; Sun: rotation; Solar wind; Astrophysics - Solar and Stellar Astrophysics |
ORFEES - a radio spectrograph for the study of solar radio bursts and space weather applications Radio bursts are sensitive tracers of non-thermal electron populations in the solar corona. They are produced by electron beams and shock waves propagating through the corona and the heliosphere, and by trapped electron populations in coronal mass ejections (CMEs) and in quiescent active regions. Combining space-borne and ground-based radio spectrographs allows one to track disturbances between the low corona, near or at the sites of particle acceleration, and the spacecraft. Radio observations are, therefore, a significant ... Hamini, Abdallah; Auxepaules, Gabriel; ee, Lionel; Kenfack, Guy; Kerdraon, Alain; Klein, Karl-Ludwig; Lespagnol, Patrice; Masson, Sophie; Coutouly, Lucile; Fabrice, Christian; Romagnan, Renaud; Published by: Journal of Space Weather and Space Climate Published on: oct YEAR: 2021   DOI: 10.1051/swsc/2021039 Parker Data Used; Astronomical instrumentation; methods and techniques; Sun: activity; Sun: corona; Sun: coronal mass ejections (CMEs); Sun: radio radiation |
Measurement of the open magnetic flux in the inner heliosphere down to 0.13 AU Context. Robustly interpreting sets of in situ spacecraft data of the heliospheric magnetic field (HMF) for the purpose of probing the total unsigned magnetic flux in the heliosphere is critical for constraining global coronal models as well as understanding the large scale structure of the heliosphere itself. The heliospheric flux (\ensuremath\Phi$_H$) is expected to be a spatially conserved quantity with a possible secular dependence on the solar cycle and equal to the measured radial component of the HMF weighted by the s ... Badman, Samuel; Bale, Stuart; Rouillard, Alexis; Bowen, Trevor; Bonnell, John; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Published by: \aap Published on: jun YEAR: 2021   DOI: 10.1051/0004-6361/202039407 Parker Data Used; Sun: corona; Sun: magnetic fields; Sun: heliosphere; Solar wind; methods: data analysis; methods: statistical; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2 Context. We investigated the source of a type III radio burst storm during encounter 2 of NASA s Parker Solar Probe (PSP) mission. Harra, L.; Brooks, D.; Bale, S.; Mandrini, C.; Barczynski, K.; Sharma, R.; Badman, S.; Domínguez, Vargas; Pulupa, M.; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021   DOI: 10.1051/0004-6361/202039514 Sun: corona; Solar wind; Sun: radio radiation; Sun: abundances; Sun: atmosphere; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics; Parker Data Used |
Context. Periodicities have frequently been reported across many wavelengths in the solar corona. Correlated periods of ~5 min, comparable to solar p-modes, are suggestive of coupling between the photosphere and the corona. Cattell, Cynthia; Glesener, Lindsay; Leiran, Benjamin; Dombeck, John; Goetz, Keith; Oliveros, Juan; Badman, Samuel; Pulupa, Marc; Bale, Stuart; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021   DOI: 10.1051/0004-6361/202039510 Sun: radio radiation; Sun: corona; Sun: X-rays; gamma rays; Sun: oscillations; magnetic reconnection; radiation mechanisms: non-thermal; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics; Parker Data Used |
Context. Parker Solar Probe (PSP) is providing an unprecedented view of the Sun s corona as it progressively dips closer into the solar atmosphere with each solar encounter. Each set of observations provides a unique opportunity to test and constrain global models of the solar corona and inner heliosphere and, in turn, use the model results to provide a global context for interpreting such observations. Riley, Pete; Lionello, Roberto; Caplan, Ronald; Downs, Cooper; Linker, Jon; Badman, Samuel; Stevens, Michael; Published by: Astronomy and Astrophysics Published on: 06/2021 YEAR: 2021   DOI: 10.1051/0004-6361/202039815 Sun: corona; Sun: heliosphere; Sun: magnetic fields; Solar wind; Sun: evolution; Interplanetary medium; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used |
2020 |
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 |
Alfv\ enic fluctuations in solar wind are an intrinsic property of fast streams, while slow intervals typically have a very low degree of Alfv\ enicity, with much more variable parameters. However, sometimes a slow wind can be highly Alfv\ enic. Here we compare three different regimes of solar wind, in terms of Alfv\ enic content and spectral properties, during a minimum phase of the solar activity and at 0.3 au. We show that fast and Alfv\ enic slow intervals share some common characteristics. This would suggest a simila ... Perrone, D.; D\textquoterightAmicis, R.; De Marco, R.; Matteini, L.; Stansby, D.; Bruno, R.; Horbury, T.; Published by: Astronomy \& Astrophysics Published on: 01/2020 YEAR: 2020   DOI: 10.1051/0004-6361/201937064 parker solar probe; plasmas; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere; turbulence |
2019 |
Self-induced Scattering of Strahl Electrons in the Solar Wind We investigate the scattering of strahl electrons by microinstabilities as a mechanism for creating the electron halo in the solar wind. We develop a mathematical framework for the description of electron-driven microinstabilities and discuss the associated physical mechanisms. We find that an instability of the oblique fast-magnetosonic/whistler (FM/W) mode is the best candidate for a microinstability that scatters strahl electrons into the halo. We derive approximate analytic expressions for the FM/W instability thresho ... Verscharen, Daniel; Chandran, Benjamin; Jeong, Seong-Yeop; Salem, Chadi; Pulupa, Marc; Bale, Stuart; Published by: The Astrophysical Journal Published on: 12/2019 YEAR: 2019   DOI: 10.3847/1538-4357/ab4c30 Astrophysics - Solar and Stellar Astrophysics; instabilities; parker solar probe; Physics - Geophysics; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; Sun: corona; turbulence; waves |
Magnetic Field Line Twisting by Photospheric Vortices: Energy Storage and Release Rappazzo, A.~F.; Velli, M.; Dahlburg, R.~B.; Einaudi, G.; Published by: \apj Published on: 10/2019 YEAR: 2019   DOI: 10.3847/1538-4357/ab3c69 Parker Data Used; magnetohydrodynamics: MHD; Sun: corona; Sun: coronal mass ejections: CMEs; Astrophysics - Solar and Stellar Astrophysics |
A strong correlation between speed and proton temperature has been observed, across many years, on hourly averaged measurements in the solar wind. Here, we show that this relationship is also observed at a smaller scale on intervals of a few days, within a single stream. Following the radial evolution of a well-defined stream of coronal-hole plasma, we show that the temperature-speed (T-V) relationship evolves with distance, implying that the T-V relationship at 1 au cannot be used as a proxy for that near the Sun. We sug ... Perrone, Denise; Stansby, D; Horbury, T; Matteini, L; Published by: Monthly Notices of the Royal Astronomical Society Published on: 09/2019 YEAR: 2019   DOI: 10.1093/mnras/stz1877 parker solar probe; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere |
NASA\textquoterights Parker Solar Probe (PSP) spacecraft reached its first perihelion of 35.7 solar radii on 2018 November 5. To aid in mission planning, and in anticipation of the unprecedented measurements to be returned, in late October, we developed a three-dimensional magnetohydrodynamic (MHD) solution for the solar corona and inner heliosphere, driven by the then available observations of the Sun\textquoterights photospheric magnetic field. Our model incorporates a wave-turbulence-driven model to heat the corona. He ... Riley, Pete; Downs, Cooper; Linker, Jon; Mikic, Zoran; Lionello, Roberto; Caplan, Ronald; Published by: The Astrophysical Journal Published on: 04/2019 YEAR: 2019   DOI: 10.3847/2041-8213/ab0ec3 Astrophysics - Solar and Stellar Astrophysics; magnetohydrodynamics: MHD; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere; Sun: magnetic fields; waves |
Combined geometrical modelling and white-light mass determination of coronal mass ejections Pluta, Adam; Mrotzek, Niclas; Vourlidas, Angelos; Bothmer, Volker; Savani, Neel; Published by: \aap Published on: 03/2019 YEAR: 2019   DOI: 10.1051/0004-6361/201833829 Parker Data Used; Sun: coronal mass ejections (CMEs); solar-terrestrial relations; Sun: heliosphere; Sun: corona |
Large-scale Magnetic Funnels in the Solar Corona Panasenco, Olga; Velli, Marco; Panasenco, Aram; Published by: \apj Published on: 03/2019 YEAR: 2019   DOI: 10.3847/1538-4357/ab017c Parker Data Used; Solar wind; Sun: activity; Sun: corona; Sun: coronal mass ejections: CMEs; Sun: filaments; prominences; Sun: magnetic fields |
Contextual Predictions for the Parker Solar Probe . I. Critical Surfaces and Regions The solar corona and young solar wind may be characterized by critical surfaces\textemdashthe sonic, Alfv\ en, and first plasma-β unity surfaces\textemdashthat demarcate regions where the solar wind flow undergoes certain crucial transformations. Global numerical simulations and remote sensing observations offer a natural mode for the study of these surfaces at large scales, thus providing valuable context for the high-resolution in situ measurements expected from the recently launched Parker Solar Probe (PSP). The prese ... Chhiber, Rohit; Usmanov, Arcadi; Matthaeus, William; Goldstein, Melvyn; Published by: The Astrophysical Journal Supplement Series Published on: 03/2019 YEAR: 2019   DOI: 10.3847/1538-4365/ab0652 Astrophysics - Solar and Stellar Astrophysics; magnetohydrodynamics: MHD; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus; Solar wind; Sun: corona; turbulence |
Dissipation Scale Lengths of Solar Wind Turbulence Raja, Sasikumar; Subramanian, Prasad; Ingale, Madhusudan; Ramesh, R.; Published by: \apj Published on: 02/2019 YEAR: 2019   DOI: 10.3847/1538-4357/aafd33 occultations; scattering; Solar wind; Sun: corona; turbulence; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
2018 |
Dependence of Coronal Loop Temperature on Loop Length and Magnetic Field Strength Dahlburg, R.~B.; Einaudi, G.; Ugarte-Urra, I.; Rappazzo, A.~F.; Velli, M.; Published by: \apj Published on: 12/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aae535 Parker Data Used; magnetohydrodynamics: MHD; Sun: activity; Sun: corona; turbulence |
Magnetic Helicity Reversal in the Corona at Small Plasma Beta Solar and stellar dynamos shed small-scale and large-scale magnetic helicity of opposite signs. However, solar wind observations and simulations have shown that some distance above the dynamo both the small-scale and large-scale magnetic helicities have reversed signs. With realistic simulations of the solar corona above an active region now being available, we have access to the magnetic field and current density along coronal loops. We show that a sign reversal in the horizontal averages of the magnetic helicity occurs ... Bourdin, Philippe; Singh, Nishant; Brandenburg, Axel; Published by: The Astrophysical Journal Published on: 12/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aae97a Astrophysics - Solar and Stellar Astrophysics; dynamo; magnetohydrodynamics: MHD; methods: numerical; parker solar probe; Physics - Plasma Physics; Solar Probe Plus; Solar wind; Sun: corona; Sun: magnetic fields |
Deep-space exploration of the inner heliosphere is in an unprecedented golden age, with the recent and forthcoming launches of the Parker Solar Probe (PSP) and Solar Orbiter (SolO) missions, respectively. In order to both predict and understand the prospective observations by PSP and SolO, we perform forward MHD modeling of the 3D inner heliosphere at solar minimum, and synthesize the white-light (WL) emission that would result from Thomson scattering of sunlight from the coronal and heliospheric plasmas. Both solar rotat ... Xiong, Ming; Davies, Jackie; Feng, Xueshang; Li, Bo; Yang, Liping; Xia, Lidong; Harrison, Richard; Hayashi, Keiji; Li, Huichao; Zhou, Yufen; Published by: The Astrophysical Journal Published on: 12/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aae978 magnetohydrodynamics: MHD; methods: numerical; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere |
In situ spacecraft observations provide much-needed constraints on theories of solar wind formation and release, particularly the highly variable slow solar wind, which dominates near-Earth space. Previous studies have shown an association between local inversions in the heliospheric magnetic field (HMF) and solar wind released from the vicinity of magnetically closed coronal structures. We here show that in situ properties of inverted HMF are consistent with the same hot coronal source regions as the slow solar wind. We ... Owens, Mathew; Lockwood, Mike; Barnard, Luke; Macneil, Allan; Published by: The Astrophysical Journal Published on: 11/2018 YEAR: 2018   DOI: 10.3847/2041-8213/aaee82 parker solar probe; Solar Probe Plus; Solar wind; Sun: activity; Sun: corona; Sun: magnetic fields |
Spatial Expansion and Speeds of Type III Electron Beam Sources in the Solar Corona A component of space weather, electron beams are routinely accelerated in the solar atmosphere and propagate through interplanetary space. Electron beams interact with Langmuir waves resulting in type III radio bursts. They expand along the trajectory and, using kinetic simulations, we explore the expansion as the electrons propagate away from the Sun. Specifically, we investigate the front, peak, and back of the electron beam in space from derived radio brightness temperatures of fundamental type III emission. The front ... Published by: The Astrophysical Journal Published on: 11/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aae5d4 Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Solar Probe Plus; Solar wind; Sun: corona; Sun: flares; Sun: particle emission; Sun: radio radiation |
Simulated Encounters of the Parker Solar Probe with a Coronal-hole Jet Solar coronal jets are small, transient, collimated ejections most easily observed in coronal holes (CHs). The upcoming Parker Solar Probe (PSP) mission provides the first opportunity to encounter CH jets in situ near the Sun and examine their internal structure and dynamics. Using projected mission orbital parameters, we have simulated PSP encounters with a fully three-dimensional magnetohydrodynamic (MHD) model of a CH jet. We find that three internal jet regions, featuring different wave modes and levels of compressibi ... Roberts, Merrill; Uritsky, Vadim; DeVore, Richard; Karpen, Judith; Published by: The Astrophysical Journal Published on: 10/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aadb41 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Solar Probe Plus; Solar wind; Sun: activity; Sun: corona; Sun: heliosphere; Sun: magnetic fields |
Usmanov, Arcadi; Matthaeus, William; Goldstein, Melvyn; Chhiber, Rohit; Published by: \apj Published on: 09/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aad687 Parker Data Used; magnetohydrodynamics: MHD; methods: numerical; Solar wind; Sun: corona; Sun: rotation; turbulence |
Stenborg, Guillermo; Howard, Russell; Stauffer, Johnathan; Published by: \apj Published on: 08/2018 YEAR: 2018   DOI: 10.3847/1538-4357/aacea3 Parker Data Used; methods: data analysis; scattering; Sun: corona; techniques: image processing; zodiacal dust |
Short, large-amplitude speed enhancements in the near-Sunfast solar wind We report the presence of intermittent, short discrete enhancements in plasma speed in the near-Sun high-speed solar wind. Lasting tens of seconds to minutes in spacecraft measurements at 0.3 au, speeds inside these enhancements can reach 1000 km s-1, corresponding to a kinetic energy up to twice that of the bulk high-speed solar wind. These events, which occur around 5 per cent of the time, are Alfv\ enic in nature with large magnetic field deflections and are the same temperature as the surrounding plasma, in ... Horbury, T; Matteini, L; Stansby, D; Published by: Monthly Notices of the Royal Astronomical Society Published on: 08/2018 YEAR: 2018   DOI: 10.1093/mnras/sty953 parker solar probe; Solar Probe Plus; Solar wind; Sun: corona |
Chhiber, Rohit; Usmanov, Arcadi; DeForest, Craig; Matthaeus, William; Parashar, Tulasi; Goldstein, Melvyn; Published by: \apjl Published on: 04/2018 YEAR: 2018   DOI: 10.3847/2041-8213/aab843 Parker Data Used; magnetohydrodynamics: MHD; Solar wind; Sun: corona; turbulence |
Radial evolution of the solar wind in pure high-speed streams: HELIOS revised observations Spacecraft observations have shown that the proton temperature in the solar wind falls off with radial distance more slowly than expected for an adiabatic prediction. Usually, previous studies have been focused on the evolution of the solar-wind plasma by using the bulk speed as an order parameter to discriminate different regimes. In contrast, here, we study the radial evolution of pure and homogeneous fast streams (i.e. well-defined streams of coronal-hole plasma that maintain their identity during several solar rotatio ... Perrone, Denise; Stansby, D; Horbury, T; Matteini, L; Published by: Monthly Notices of the Royal Astronomical Society Published on: 03/2019 YEAR: 2018   DOI: 10.1093/mnras/sty3348 parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere |
Solar-wind predictions for the Parker Solar Probe Orbit Context. The Parker Solar Probe (PSP; formerly Solar Probe Plus) mission will be humanitys first in situ exploration of the solar corona with closest perihelia at 9.86 solar radii (R☉) distance to the Sun. It will help answer hitherto unresolved questions on the heating of the solar corona and the source and acceleration of the solar wind and solar energetic particles. The scope of this study is to model the solar-wind environment for PSPs unprecedented distances in its prime mission phase during the years 20 ... Published by: Astronomy \& Astrophysics Published on: 03/2018 YEAR: 2018   DOI: 10.1051/0004-6361/201731831 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere |
Spectroscopic Measurements of the Ion Velocity Distribution at the Base of the Fast Solar Wind In situ measurements of the fast solar wind reveal non-thermal distributions of electrons, protons, and minor ions extending from 0.3 au to the heliopause. The physical mechanisms responsible for these non-thermal properties and the location where these properties originate remain open questions. Here, we present spectroscopic evidence, from extreme ultraviolet spectroscopy, that the velocity distribution functions (VDFs) of minor ions are already non-Gaussian at the base of the fast solar wind in a coronal hole, at altit ... Jeffrey, Natasha; Hahn, Michael; Savin, Daniel; Fletcher, Lyndsay; Published by: The Astrophysical Journal Published on: 03/2018 YEAR: 2018   DOI: 10.3847/2041-8213/aab08c Astrophysics - Solar and Stellar Astrophysics; line: profiles; parker solar probe; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere; Sun: UV radiation; techniques: spectroscopic |
2017 |
Recent observations have shown that coronal shocks driven by coronal mass ejections can develop and accelerate particles within several solar radii in large solar energetic particle (SEP) events. Motivated by this, we present an SEP acceleration study that including the process in which a fast shock propagates through a streamer-like magnetic field with both closed and open field lines in the low corona region. The acceleration of protons is modeled by numerically solving the Parker transport equation with spatial diffusi ... Kong, Xiangliang; Guo, Fan; Giacalone, Joe; Li, Hui; Chen, Yao; Published by: The Astrophysical Journal Published on: 12/2017 YEAR: 2017   DOI: 10.3847/1538-4357/aa97d7 acceleration of particles; Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics; shock waves; Solar Probe Plus; Sun: corona; Sun: coronal mass ejections: CMEs; Sun: magnetic fields; Sun: particle emission |
A Zone of Preferential Ion Heating Extends Tens of Solar Radii from the Sun The extreme temperatures and nonthermal nature of the solar corona and solar wind arise from an unidentified physical mechanism that preferentially heats certain ion species relative to others. Spectroscopic indicators of unequal temperatures commence within a fraction of a solar radius above the surface of the Sun, but the outer reach of this mechanism has yet to be determined. Here we present an empirical procedure for combining interplanetary solar wind measurements and a modeled energy equation including Coulomb relax ... Kasper, J.; Klein, K.; Weber, T.; Maksimovic, M.; Zaslavsky, A.; Bale, S.; Maruca, B.; Stevens, M.; Case, A.; Published by: The Astrophysical Journal Published on: 11/2017 YEAR: 2017   DOI: 10.3847/1538-4357/aa84b1 acceleration of particles; Astrophysics - Solar and Stellar Astrophysics; magnetic fields; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; Sun: corona; turbulence |
Stenborg, Guillermo; Howard, Russell; Published by: \apj Published on: 10/2017 YEAR: 2017   DOI: 10.3847/1538-4357/aa8ef0 Parker Data Used; methods: data analysis; Sun: corona; techniques: image processing |
Coronal Heating Topology: The Interplay of Current Sheets and Magnetic Field Lines Rappazzo, A.~F.; Matthaeus, W.~H.; Ruffolo, D.; Velli, M.; Servidio, S.; Published by: \apj Published on: 07/2017 YEAR: 2017   DOI: 10.3847/1538-4357/aa79f2 Parker Data Used; magnetohydrodynamics: MHD; Solar wind; Sun: activity; Sun: corona; Sun: magnetic fields; turbulence; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
White-light coronal and heliospheric imagers observe scattering of photospheric light from both dust particles (the F-Corona) and free electrons in the corona (the K-corona). The separation of the two coronae is thus vitally important to reveal the faint K-coronal structures (e.g., streamers, co-rotating interaction regions, coronal mass ejections, etc.). However, the separation of the two coronae is very difficult, so we are content in defining a background corona that contains the F- and as little K- as possible. For bo ... Stenborg, Guillermo; Howard, Russell; Published by: The Astrophysical Journal Published on: 04/2017 YEAR: 2017   DOI: 10.3847/1538-4357/aa6a12 methods: data analysis; parker solar probe; Solar Probe Plus; Sun: corona; Sun: coronal mass ejections: CMEs; techniques: image processing |
Reconnection-Driven Coronal-Hole Jets with Gravity and Solar Wind Karpen, J.~T.; DeVore, C.~R.; Antiochos, S.~K.; Pariat, E.; Published by: \apj Published on: 01/2017 YEAR: 2017   DOI: 10.3847/1538-4357/834/1/62 Parker Data Used; magnetic reconnection; magnetohydrodynamics: MHD; Solar wind; stars: jets; Sun: activity; Sun: corona; Astrophysics - Solar and Stellar Astrophysics |
2016 |
Closed-field Coronal Heating Driven by Wave Turbulence Downs, Cooper; Lionello, Roberto; c, Zoran; Linker, Jon; Velli, Marco; Published by: \apj Published on: 12/2016 YEAR: 2016   DOI: 10.3847/0004-637X/832/2/180 Parker Data Used; magnetohydrodynamics: MHD; Sun: corona; Sun: magnetic fields; turbulence; Astrophysics - Solar and Stellar Astrophysics |
Fading Coronal Structure and the Onset of Turbulence in the Young Solar Wind DeForest, C.~E.; Matthaeus, W.~H.; Viall, N.~M.; Cranmer, S.~R.; Published by: \apj Published on: 09/2016 YEAR: 2016   DOI: 10.3847/0004-637X/828/2/66 Parker Data Used; Solar wind; Sun: corona; Sun: fundamental parameters; techniques: image processing; Astrophysics - Solar and Stellar Astrophysics |
Tenerani, Anna; Velli, Marco; DeForest, Craig; Published by: \apjl Published on: 07/2016 YEAR: 2016   DOI: 10.3847/2041-8205/825/1/L3 Parker Data Used; magnetic reconnection; magnetohydrodynamics: MHD; Solar wind; Sun: corona; waves |
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