|
Notice:
|
Found 639 entries in the Bibliography.
Showing entries from 251 through 300
| 2020 |
|
Switchbacks in the Near-Sun Magnetic Field: Long Memory and Impact on the Turbulence Cascade One of the most striking observations made by Parker Solar Probe during its first solar encounter is the omnipresence of rapid polarity reversals in a magnetic field that is otherwise mostly radial. These so-called switchbacks strongly affect the dynamics of the magnetic field. We concentrate here on their macroscopic properties. First, we find that these structures are self-similar, and have neither a characteristic magnitude, nor a characteristic duration. Their waiting time statistics show evidence of aggregation. The ... de Wit, Thierry; Krasnoselskikh, Vladimir; Bale, Stuart; Bonnell, John; Bowen, Trevor; Chen, Christopher; Froment, Clara; Goetz, Keith; Harvey, Peter; Jagarlamudi, Vamsee; Larosa, Andrea; MacDowall, Robert; Malaspina, David; Matthaeus, William; Pulupa, Marc; Velli, Marco; Whittlesey, Phyllis; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5853 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
Switchbacks (rotations of the magnetic field) are observed on the Parker Solar Probe. Their evolution, content, and plasma effects are studied in this paper. The solar wind does not receive a net acceleration from switchbacks that it encountered upstream of the observation point. The typical switchback rotation angle increased with radial distance. Significant Poynting fluxes existed inside, but not outside, switchbacks, and the dependence of the Poynting flux amplitude on the switchback radial location and rotation angle ... Mozer, F.; Agapitov, O.; Bale, S.; Bonnell, J.; Case, T.; Chaston, C.; Curtis, D.; de Wit, Dudok; Goetz, K.; Goodrich, K.; Harvey, P.; Kasper, J.; Korreck, K.; Krasnoselskikh, V.; Larson, D.; Livi, R.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Stevens, M.; Whittlesey, P.; Wygant, J.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab7196 |
|
Time Domain Structures and Dust in the Solar Vicinity: Parker Solar Probe Observations On 2019 April 5, while the Parker Solar Probe was at its 35 solar radius perihelion, the data set collected at 293 samples/s contained more than 10,000 examples of spiky electric-field-like structures with durations less than 200 milliseconds and amplitudes greater than 10 mV m-1. The vast majority of these events were caused by plasma turbulence. Defining dust events as those with similar, narrowly peaked, positive, and single-ended signatures resulted in finding 135 clear dust events, which, after correcting ... Mozer, F.; Agapitov, O.; Bale, S.; Bonnell, J.; Goetz, K.; Goodrich, K.; Gore, R.; Harvey, P.; Kellogg, P.; Malaspina, D.; Pulupa, M.; Schumm, G.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5e4b Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
Turbulence Transport Modeling and First Orbit Parker Solar Probe ( PSP ) Observations The Parker Solar Probe (PSP) achieved its first orbit perihelion on 2018 November 6, reaching a heliocentric distance of about 0.165 au (35.55 R☉). Here, we study the evolution of fully developed turbulence associated with the slow solar wind along the PSP trajectory between 35.55 R☉ and 131.64 R☉ in the outbound direction, comparing observations to a theoretical turbulence transport model. Several turbulent quantities, such as the fluctuating kinetic energy and the corresponding cor ... Adhikari, L.; Zank, G.; Zhao, L.-L.; Kasper, J.; Korreck, K.; Stevens, M.; Case, A.; Whittlesey, P.; Larson, D.; Livi, R.; Klein, K.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5852 Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
WISPR Imaging of a Pristine CME The Wide-field Imager for Solar Probe (WISPR) on board the Parker Solar Probe (PSP) observed a coronal mass ejection (CME) on 2018 November 1, the first day of the initial PSP encounter. The speed of the CME, approximately 200-300 km s-1 in the WISPR field of view, is typical of slow, streamer blowout CMEs. This event was also observed by the Large Angle and Spectrometric Coronagraph Experiment (LASCO) coronagraphs. WISPR and LASCO view remarkably similar structures that enable useful cross-comparison between t ... Hess, Phillip; Rouillard, Alexis; Kouloumvakos, Athanasios; Liewer, Paulett; Zhang, Jie; Dhakal, Suman; Stenborg, Guillermo; Colaninno, Robin; Howard, Russell; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab4ff0 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
Tsurutani, Bruce; Lakhina, Gurbax; Hajra, Rajkumar; Published by: Nonlinear Processes in Geophysics Published on: 02/2020 YEAR: 2020 DOI: 10.5194/npg-27-75-2020 |
|
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: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab74e0 |
|
In this paper, we present an analysis of the internal structure of a coronal mass ejection (CME) detected by in situ instruments on board the Parker Solar Probe (PSP) spacecraft during its first solar encounter. On 2018 November 11 at 23:53 UT, the FIELDS magnetometer measured an increase in strength of the magnetic field as well as a coherent change in the field direction. The SWEAP instrument simultaneously detected a low proton temperature and signatures of bidirectionality in the electron pitch angle distribution (PAD ... Nieves-Chinchilla, Teresa; Szabo, Adam; Korreck, Kelly; Alzate, Nathalia; Balmaceda, Laura; Lavraud, Benoit; Paulson, Kristoff; Narock, Ayris; Wallace, Samantha; Jian, Lan; Luhmann, Janet; Morgan, Huw; Higginson, Aleida; Arge, Charles; Bale, Stuart; Case, Anthony; de Wit, Thierry; Giacalone, Joe; Goetz, Keith; Harvey, Peter; Jones-Melosky, Shaela; Kasper, J.; Larson, Davin; Livi, Roberto; McComas, David; MacDowall, Robert; Malaspina, David; Pulupa, Marc; Raouafi, Nour; Schwadron, Nathan; Stevens, Michael; Whittlesey, Phyllis; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab61f5 |
|
We discuss the solar wind electron temperatures Te as measured in the nascent solar wind by Parker Solar Probe during its first perihelion pass. The measurements have been obtained by fitting the high-frequency part of quasi-thermal noise spectra recorded by the Radio Frequency Spectrometer. In addition we compare these measurements with those obtained by the electrostatic analyzer discussed in Halekas et al. These first electron observations show an anticorrelation between Te and the wind bulk speed ... Maksimovic, M.; Bale, S.; c, Ber\v; Bonnell, J.; Case, A.; de Wit, Dudok; Goetz, K.; Halekas, J.; Harvey, P.; Issautier, K.; Kasper, J.; Korreck, K.; Jagarlamudi, Krishna; Lahmiti, N.; Larson, D.; Lecacheux, A.; Livi, R.; MacDowall, R.; Malaspina, D.; c, M.; Meyer-Vernet, N.; Moncuquet, M.; Pulupa, M.; Salem, C.; Stevens, M.; ak, \v; Velli, M.; Whittlesey, P.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab61fc |
|
During the Parker Solar Probe\textquoterights (PSP) first perihelion pass, the spacecraft reached within a heliocentric distance of ̃37 R☉ and observed numerous magnetic and flow structures characterized by sharp gradients. To better understand these intermittent structures in the young solar wind, an important property to examine is their degree of correlation in time and space. To this end, we use the well-tested partial variance of increments (PVI) technique to identify intermittent events in FIELDS and S ... Chhiber, Rohit; Goldstein, M; Maruca, B.; Chasapis, A.; Matthaeus, W.; Ruffolo, D.; Bandyopadhyay, R.; Parashar, T.; Qudsi, R.; de Wit, Dudok; Bale, S.; Bonnell, J.; Goetz, K.; Harvey, P.; MacDowall, R.; Malaspina, D.; Pulupa, M.; Kasper, J.; Korreck, K.; Case, A.; Stevens, M.; Whittlesey, P.; Larson, D.; Livi, R.; Velli, M.; Raouafi, N.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab53d2 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
Cross Helicity Reversals in Magnetic Switchbacks We consider 2D joint distributions of normalized residual energy, σr(s, t), and cross helicity, σc(s, t), during one day of Parker Solar Probe\textquoterights (PSP\textquoterights) first encounter as a function of wavelet scale s. The broad features of the distributions are similar to previous observations made by Helios in slow solar wind, namely well-correlated and fairly Alfv\ enic wind, except for a population with negative cross helicity that is seen at shorter wavelet scales. We show that thi ... McManus, Michael; Bowen, Trevor; Mallet, Alfred; Chen, Christopher; Chandran, Benjamin; Bale, Stuart; Larson, Davin; de Wit, Thierry; Kasper, J.; Stevens, Michael; Whittlesey, Phyllis; Livi, Roberto; Korreck, Kelly; Goetz, Keith; Harvey, Peter; Pulupa, Marc; MacDowall, Robert; Malaspina, David; Case, Anthony; Bonnell, J.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab6dce Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
Density Fluctuations in the Solar Wind Based on Type III Radio Bursts Observed by Parker Solar Probe Radio waves are strongly scattered in the solar wind, so that their apparent sources seem to be considerably larger and shifted than the actual ones. Since the scattering depends on the spectrum of density turbulence, a better understanding of the radio wave propagation provides indirect information on the relative density fluctuations, ϵ=⟨δn⟩/⟨n⟩\ ϵ=⟨δn⟩/⟨n⟩ , at the effective turbulence scale length. Here, we analyzed 30 type III bursts detected by Parker Sola ... Krupar, Vratislav; Szabo, Adam; Maksimovic, Milan; Kruparova, Oksana; Kontar, Eduard; Balmaceda, Laura; Bonnin, Xavier; Bale, Stuart; Pulupa, Marc; Malaspina, David; Bonnell, John; Harvey, Peter; Goetz, Keith; de Wit, Thierry; MacDowall, Robert; Kasper, Justin; Case, Anthony; Korreck, Kelly; Larson, Davin; Livi, Roberto; Stevens, Michael; Whittlesey, Phyllis; Hegedus, Alexander; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab65bd Astrophysics - Earth and Planetary Astrophysics; Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
|
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: 02/2019 YEAR: 2020 DOI: 10.3847/1538-4365/ab6610 |
|
Exploring the innermost solar atmosphere The Parker Solar Probe spacecraft completed the first two of its 24 scheduled orbits around the Sun on 18 June 2019, making history by flying halfway between Mercury and the Sun. Published by: Nature Astronomy Published on: 01/2020 YEAR: 2020 DOI: 10.1038/s41550-019-0985-7 |
|
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 |
|
Spectral signatures of recursive magnetic field reconnection Published by: \mnras Published on: 01/2020 YEAR: 2020 DOI: 10.1093/mnras/stz3310 Parker Data Used; magnetic reconnection; MHD; plasmas; turbulence; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics |
|
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\textemdashRutherford 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 ... Published by: American Journal of Physics Published on: 01/2020 YEAR: 2020 DOI: 10.1119/10.0000145 |
|
NASA probe reveals solar-wind secrets Published by: Physics World Published on: 01/2020 YEAR: 2020 DOI: 10.1088/2058-7058/33/1/6 |
|
Parker solar probe mission design A mission to the sun originally called Solar Probe was first considered in 1958 and stayed in concept and feasibility studies for five decades until 2007, when a new mission design was created that changed the original mission architecture. The re-designed mission was named Solar Probe Plus due to significant advantages in technical implementation and science return, and it was renamed Parker Solar Probe (PSP) in 2017. PSP was launched on August 12, 2018 as the first mission to touch the Sun. This paper presents an overview ... Published by: Advances in the Astronautical Sciences Published on: Astrophysics; Atomic absorption spectrometry; Interplanetary flight; Parker Engineering |
|
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 ... 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: The Astrophysical Journal Published on: YEAR: 2020 DOI: 10.3847/1538-4357/abb820 Solar wind; interplanetary turbulence; Magnetohydrodynamics; Astronomy data analysis; Astronomy databases; Parker Data Used |
| 2019 |
|
Scattering of Energetic Electrons by Heat-flux-driven Whistlers in Flares Roberg-Clark, G.~T.; Agapitov, O.; Drake, J.~F.; Swisdak, M.; Published by: \apj Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab5114 Parker Data Used; solar flares; Plasma physics; 1496; 2089; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
|
No Evidence for Critical Balance in Field-aligned Alfv\ enic Solar Wind Turbulence Telloni, Daniele; Carbone, Francesco; Bruno, Roberto; Sorriso-Valvo, Luca; Zank, Gary; Adhikari, Laxman; Hunana, Peter; Published by: \apj Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab517b Parker Data Used; interplanetary turbulence; Solar wind; Space plasmas; Alfven waves; Interplanetary medium; Magnetohydrodynamics; 830; 1534; 1544; 23; 825; 1964 |
|
Alfv\ enic velocity spikes and rotational flows in the near-Sun solar wind Kasper, J.~C.; Bale, S.~D.; Belcher, J.~W.; Berthomier, M.; Case, A.~W.; Chandran, B.~D.~G.; Curtis, D.~W.; Gallagher, D.; Gary, S.~P.; Golub, L.; Halekas, J.~S.; Ho, G.~C.; Horbury, T.~S.; Hu, Q.; Huang, J.; Klein, K.~G.; Korreck, K.~E.; Larson, D.~E.; Livi, R.; Maruca, B.; Lavraud, B.; Louarn, P.; Maksimovic, M.; Martinovic, M.; McGinnis, D.; Pogorelov, N.~V.; Richardson, J.~D.; Skoug, R.~M.; Steinberg, J.~T.; Stevens, M.~L.; Szabo, A.; Velli, M.; Whittlesey, P.~L.; Wright, K.~H.; Zank, G.~P.; MacDowall, R.~J.; McComas, D.~J.; McNutt, R.~L.; Pulupa, M.; Raouafi, N.~E.; Schwadron, N.~A.; Published by: \nat Published on: 12/2019 YEAR: 2019 DOI: 10.1038/s41586-019-1813-z |
|
The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPW on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts have been observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of space missions to derive dust fluxes. Here, we consider the details of dust impacts, subsequent development of the impact gene ... Mann, Ingrid; ak, Libor; Vaverka, Jakub; Antonsen, Tarjei; Fredriksen, \r; Issautier, Karine; Malaspina, David; Meyer-Vernet, Nicole; u, Ji\v; Sternovsky, Zoltan; Stude, Joan; Ye, Shengyi; Zaslavsky, Arnaud; Published by: Annales Geophysicae Published on: 12/2019 YEAR: 2019 DOI: 10.5194/angeo-37-1121-2019 |
|
Electron Energy Partition across Interplanetary Shocks. II. Statistics A statistical analysis of 15,210 electron velocity distribution function (VDF) fits, observed within \textpm2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented. This is the second in a three-part series on electron VDFs near IP shocks. The electron velocity moment statistics for the dense, low-energy core, tenuous, hot halo, and field-aligned beam/strahl are a statistically significant list of values illustrated with both histograms and tabular lists for reference and baselines in future w ... Wilson, Lynn; Chen, Li-Jen; Wang, Shan; Schwartz, Steven; Turner, Drew; Stevens, Michael; Kasper, Justin; Osmane, Adnane; Caprioli, Damiano; Bale, Stuart; Pulupa, Marc; Salem, Chadi; Goodrich, Katherine; Published by: The Astrophysical Journal Supplement Series Published on: 12/2019 YEAR: 2019 DOI: 10.3847/1538-4365/ab5445 Astrophysics - Solar and Stellar Astrophysics; Interplanetary particle acceleration; Interplanetary shocks; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Plasma astrophysics; Plasma physics; Solar coronal mass ejection shocks; Solar coronal mass ejections; Solar Probe Plus; Solar wind; Space plasmas |
|
Highly structured slow solar wind emerging from an equatorial coronal hole During the solar minimum, when the Sun is at its least active, the solar wind is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfv\ enic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain; theories and observations suggest that they may originate at the tips of ... Bale, S.; Badman, S.; Bonnell, J.; Bowen, T.; Burgess, D.; Case, A.; Cattell, C.; Chandran, B.; Chaston, C.; Chen, C.; Drake, J.; de Wit, Dudok; Eastwood, J.; Ergun, R.; Farrell, W.; Fong, C.; Goetz, K.; Goldstein, M.; Goodrich, K.; Harvey, P.; Horbury, T.; Howes, G.; Kasper, J.; Kellogg, P.; Klimchuk, J.; Korreck, K.; Krasnoselskikh, V.; Krucker, S.; Laker, R.; Larson, D.; MacDowall, R.; Maksimovic, M.; Malaspina, D.; Martinez-Oliveros, J.; McComas, D.; Meyer-Vernet, N.; Moncuquet, M.; Mozer, F.; Phan, T.; Pulupa, M.; Raouafi, N.; Salem, C.; Stansby, D.; Stevens, M.; Szabo, A.; Velli, M.; Woolley, T.; Wygant, J.; Published by: Nature Published on: 12/2019 YEAR: 2019 DOI: 10.1038/s41586-019-1818-7 |
|
Near-Sun observations of an F-corona decrease and K-corona fine structure Remote observations of the solar photospheric light scattered by electrons (the K-corona) and dust (the F-corona or zodiacal light) have been made from the ground during eclipses and from space at distances as small as 0.3 astronomical units to the Sun. Previous observations of dust scattering have not confirmed the existence of the theoretically predicted dust-free zone near the Sun. The transient nature of the corona has been well characterized for large events, but questions still remain (for example, about the initiat ... Howard, R.; Vourlidas, A.; Bothmer, V.; Colaninno, R.; Deforest, C.; Gallagher, B.; Hall, J.; Hess, P.; Higginson, A.; Korendyke, C.; Kouloumvakos, A.; Lamy, P.; Liewer, P.; Linker, J.; Linton, M.; Penteado, P.; Plunkett, S.; Poirier, N.; Raouafi, N.; Rich, N.; Rochus, P.; Rouillard, A.; Socker, D.; Stenborg, G.; Thernisien, A.; Viall, N.; Published by: Nature Published on: 12/2019 YEAR: 2019 DOI: 10.1038/s41586-019-1807-x |
|
Probing the energetic particle environment near the Sun NASA\textquoterights Parker Solar Probe mission recently plunged through the inner heliosphere of the Sun to its perihelia, about 24 million kilometres from the Sun. Previous studies farther from the Sun (performed mostly at a distance of 1 astronomical unit) indicate that solar energetic particles are accelerated from a few kiloelectronvolts up to near-relativistic energies via at least two processes: "impulsive" events, which are usually associated with magnetic reconnection in solar flares and are typically enriched in ... McComas, D.; Christian, E.; Cohen, C.; Cummings, A.; Davis, A.; Desai, M.; Giacalone, J.; Hill, M.; Joyce, C.; Krimigis, S.; Labrador, A.; Leske, R.; Malandraki, O.; Matthaeus, W.; McNutt, R.; Mewaldt, R.; Mitchell, D.; Posner, A.; Rankin, J.; Roelof, E.; Schwadron, N.; Stone, E.; Szalay, J.; Wiedenbeck, M.; Bale, S.; Kasper, J.; Case, A.; Korreck, K.; MacDowall, R.; Pulupa, M.; Stevens, M.; Rouillard, A.; Published by: Nature Published on: 12/2019 YEAR: 2019 DOI: 10.1038/s41586-019-1811-1 |
|
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 |
|
A step closer to the Sun\textquoterights secrets NASA\textquoterights Parker Solar Probe is currently making a series of close encounters with the Sun. Initial observations from the spacecraft have improved our understanding of both the Sun and its environment. Published by: Nature Published on: 12/2019 YEAR: 2019 DOI: 10.1038/d41586-019-03665-3 |
|
Sun-bombing spacecraft uncovers secrets of the solar wind Surprise magnetic reversals and an unexpectedly fast rotating wind mark the first findings from NASA\textquoterights Parker Solar Probe. Published by: Nature Published on: 12/2019 YEAR: 2019 DOI: 10.1038/d41586-019-03684-0 |
|
Ion Cyclotron Waves in Field-aligned Solar Wind Turbulence Telloni, Daniele; Carbone, Francesco; Bruno, Roberto; Zank, Gary; Sorriso-Valvo, Luca; Mancuso, Salvatore; Published by: \apjl Published on: 11/2019 YEAR: 2019 DOI: 10.3847/2041-8213/ab4c44 Parker Data Used; Magnetohydrodynamics; Space plasmas; Solar wind; interplanetary turbulence; Alfven waves; 1964; 1544; 1534; 830; 23 |
|
The Long-standing Closure Crisis in Coronal Plasmas Coronal and solar wind physics have long used plasma fluid models to motivate physical explanations of observations; the hypothesized model is introduced into a fluid simulation to see if observations are reproduced. This procedure is called Verification of Mechanism (VoM) modeling; it is contingent on the self consistency of the closure that made the simulation possible. Inner corona VoMs typically assume weak gradient Spitzer-Braginskii closures. Four prominent coronal VoMs in place for decades are shown to contradict t ... Published by: The Astrophysical Journal Published on: 11/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab48e0 Astrophysical fluid dynamics; parker solar probe; Solar corona; Solar coronal heating; Solar Probe Plus; Solar wind |
|
Validation of MHD Model Predictions of the Corona with LASCO-C2 Polarized Brightness Images Progress in our understanding of the solar corona requires that the results of advanced magnetohydrodynamic models driven by measured magnetic fields, and particularly the underlying heating models, be thoroughly compared with coronal observations. The comparison has so far mainly concerned the global morphology of the corona, synthetic images calculated from the models being compared with observed images. We go one step further by performing detailed quantitative comparisons between the calculated polarized radiance p B ... Lamy, Philippe; Floyd, Olivier; Mikic, Zoran; Riley, Pete; Published by: Solar Physics Published on: 11/2019 YEAR: 2019 DOI: 10.1007/s11207-019-1549-9 Corona; Eclipses; LASCO; Magnetohydrodynamics; Observations; Parker Data Used; parker solar probe; quiet; Solar Probe Plus |
|
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 |
|
Large-scale parallel electric fields and return currents in a global simulation model Arnold, H.; Drake, J.~F.; Swisdak, M.; Dahlin, J.; Published by: Physics of Plasmas Published on: 10/2019 YEAR: 2019 DOI: 10.1063/1.5120373 Parker Data Used; Physics - Plasma Physics; Physics - Space Physics |
|
Zhang, Qile; Drake, J.~F.; Swisdak, M.; Published by: Physics of Plasmas Published on: 10/2019 YEAR: 2019 DOI: 10.1063/1.5121782 Parker Data Used; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
The evolution of the magnetic field and plasma quantities inside a coronal mass ejection (CME) with distance are known from statistical studies using data from 1 au monitors, planetary missions, Helios, and Ulysses. This does not cover the innermost heliosphere, below 0.29 au, where no data are yet publicly available. Here, we describe the evolution of the properties of simulated CMEs in the inner heliosphere using two different initiation mechanisms. We compare the radial evolution of these properties with that found fro ... Al-Haddad, Nada; Lugaz, No\; Poedts, Stefaan; Farrugia, Charles; Nieves-Chinchilla, Teresa; Roussev, Ilia; Published by: The Astrophysical Journal Published on: 10/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab4126 Astrophysics - Solar and Stellar Astrophysics; Ejecta; interplanetary magnetic fields; Interplanetary physics; parker solar probe; Solar coronal mass ejections; Solar Probe Plus |
|
By assuming that the solar wind flow is spherically symmetric and that the flow speed becomes constant beyond some critical distance r = R 0 (neglecting solar gravitation and acceleration by high coronal temperature), the large-scale solar wind magnetic field lines are distorted into a Parker spiral configuration, which is usually simplified to an Archimedes spiral. Using magnetic field observations near Mercury, Venus, and Earth during solar maximum of Solar Cycle 24, we statistically surveyed the Parker spira ... Chang, Qing; Xu, Xiaojun; Xu, Qi; Zhong, Jun; Xu, Jiaying; Wang, Jing; Zhang, Tielong; Published by: The Astrophysical Journal Published on: 10/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab412a parker solar probe; planets and satellites: magnetic fields; Solar Probe Plus; Solar wind; Sun: activity; Sun: magnetic fields |
|
The large-scale features of the solar wind are examined in order to predict small-scale features of turbulence in unexplored regions of the heliosphere. The strategy is to examine how system size, or effective Reynolds number Re, varies, and then how this quantity influences observable statistical properties, including intermittency properties of solar wind turbulence. The expectation based on similar hydrodynamics scalings is that the kurtosis, of the small-scale magnetic field increments, will increase with increasing R ... Parashar, T.; Cuesta, M.; Matthaeus, W.; Published by: The Astrophysical Journal Published on: 10/2019 YEAR: 2019 DOI: 10.3847/2041-8213/ab4a82 Heliosphere; interplanetary turbulence; parker solar probe; Physics - Space Physics; Plasma astrophysics; Solar Probe Plus; Solar wind; Space plasmas |
|
Solar Wind Temperature Isotropy Reliable models of the solar wind in the near-Earth space environment may constrain conditions close to the Sun. This is relevant to NASA\textquoterights contemporary innerheliospheric mission Parker Solar Probe. Among the outstanding issues is how to explain the solar wind temperature isotropy. Perpendicular and parallel proton and electron temperatures near 1 AU are theoretically predicted to be unequal, but in situ observations show quasi-isotropy sufficiently below the instability threshold condition. This has not bee ... Yoon, P.; Seough, J.; Salem, C.; Klein, K.; Published by: Physical Review Letters Published on: 10/2019 YEAR: 2019 DOI: 10.1103/PhysRevLett.123.145101 |
|
Velocity distributions of particles are key elements in the study of solar wind. The physical mechanisms that regulate their many features are a matter of debate. The present work addresses the subject with a fully analytical method in order to establish the shape of particle velocity distributions in solar wind. The method consists of solving the steady-state kinetic equation for particles and the related fluid equations, with spatial profiles for density and temperature that match general observational data. The model i ... Published by: The Astrophysical Journal Published on: 09/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab2fcd Interplanetary particle acceleration; Kappa mechanism; Parallel field; parker solar probe; Solar coronal transients; Solar Probe Plus; Solar wind |
|
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 |
|
Correcting Parker Solar Probe Electron Measurements for Spacecraft Magnetic and Electric Fields The spacecraft body of the Parker Solar Probe may interfere with electron measurements in two ways. The first is the presence of several permanent magnets near the Solar Probe Analyzers (SPAN) instruments. The second is the widely varying spacecraft potential. We estimate the effect of these interferences by performing particle tracing simulations on electrons of various energies using a simplified model of the spacecraft potential and measurements of the magnetic fields. From this we can (1) estimate the individual and comb ... McGinnis, Daniel; Halekas, Jasper; Whittlesey, Phyllis; Larson, Davin; Kasper, Justin; Published by: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS Published on: 09/2019 YEAR: 2019 DOI: 10.1029/2019JA026823 |
|
Reflection-driven magnetohydrodynamic turbulence in the solar atmosphere and solar wind Chandran, Benjamin; Perez, Jean; Published by: Journal of Plasma Physics Published on: 08/2019 YEAR: 2019 DOI: 10.1017/S0022377819000540 Parker Data Used; astrophysical plasmas; plasma nonlinear phenomena; space plasma physics; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
|
Singh, K.~A.~P.; Pucci, Fulvia; Tenerani, Anna; Shibata, Kazunari; Hillier, Andrew; Velli, Marco; Published by: \apj Published on: 08/2019 YEAR: 2019 DOI: 10.3847/1538-4357/ab2b99 Parker Data Used; magnetic reconnection; magnetohydrodynamics: MHD; plasmas; Physics - Plasma Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
Role of magnetic field curvature in magnetohydrodynamic turbulence Yang, Yan; Wan, Minping; Matthaeus, William; Shi, Yipeng; Parashar, Tulasi; Lu, Quanming; Chen, Shiyi; Published by: Physics of Plasmas Published on: 08/2019 YEAR: 2019 DOI: 10.1063/1.5099360 Parker Data Used; Physics - Space Physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
|
The UltraViolet Coronagraph Spectrometer (UVCS) on board the SOlar and Heliospheric Observatory has almost continuously observed, throughout the whole solar cycle 23, the UV solar corona. This work addresses the first-ever statistical analysis of the daily UVCS observations, performed in the O VI channel, of the northern polar coronal hole, between 1.5 and 3 R ☉, during the period of low solar activity from 1996 April to 1997 December. The study is based on the investigation, at different heights, of the corr ... Telloni, Daniele; Giordano, Silvio; Antonucci, Ester; Published by: The Astrophysical Journal Published on: 08/2019 YEAR: 2019 DOI: 10.3847/2041-8213/ab3731 parker solar probe; Solar corona; Solar coronal heating; Solar Probe Plus; Solar wind; The Sun |
|
The first definitely interstellar object 1I/\textquoterightOumuamua (previously A/2017 U1) observed in our solar system provides the opportunity to directly study material from an other star system. Can such objects be intercepted? The challenge of reaching the object within a reasonable timeframe is formidable due to its high heliocentric hyperbolic excess velocity of about 26 km/s; much faster than any vehicle yet launched. This paper presents a high-level analysis of potential near-term options for a mission to 1I/\tex ... Hein, Andreas; Perakis, Nikolaos; Eubanks, Marshall; Hibberd, Adam; Crowl, Adam; Hayward, Kieran; Kennedy, Robert; Osborne, Richard; Published by: Acta Astronautica Published on: 08/2019 YEAR: 2019 DOI: 10.1016/j.actaastro.2018.12.042 |
|
Single-spacecraft Identification of Flux Tubes and Current Sheets in the Solar Wind A novel technique is presented for describing and visualizing the local topology of the magnetic field using single-spacecraft data in the solar wind. The approach merges two established techniques: the Grad-Shafranov (GS) reconstruction method, which provides a plausible regional two-dimensional magnetic field surrounding the spacecraft trajectory, and the Partial Variance of Increments (PVI) technique that identifies coherent magnetic structures, such as current sheets. When applied to one month of Wind magnetic field d ... Pecora, Francesco; Greco, Antonella; Hu, Qiang; Servidio, Sergio; Chasapis, Alexandros; Matthaeus, William; Published by: The Astrophysical Journal Published on: 08/2019 YEAR: 2019 DOI: 10.3847/2041-8213/ab32d9 interplanetary turbulence; magnetic fields; parker solar probe; Solar Probe Plus; Solar wind |
