|
Notice:
|
Found 35 entries in the Bibliography.
Showing entries from 1 through 35
| 2023 |
|
New Observations of Solar Wind 1/f Turbulence Spectrum from Parker Solar Probe The trace magnetic power spectrum in the solar wind is known to be characterized by a double power law at scales much larger than the proton gyro-radius, with flatter spectral exponents close to -1 found at the lower frequencies below an inertial range with indices closer to [-1.5, -1.67]. The origin of the 1/f range is still under debate. In this study, we selected 109 magnetically incompressible solar wind intervals (\ensuremath\delta\ensuremath\mid B \ensuremath\mid/\ensuremath\mid B \ensuremath\mid \ensuremath\ll 1) from ... Huang, Zesen; Sioulas, Nikos; Shi, Chen; Velli, Marco; Bowen, Trevor; Davis, Nooshin; Chandran, B.~D.~G.; Matteini, Lorenzo; Kang, Ning; Shi, Xiaofei; Huang, Jia; Bale, Stuart; Kasper, J.~C.; Larson, Davin; Livi, Roberto; Whittlesey, P.~L.; Rahmati, Ali; Paulson, Kristoff; Stevens, M.; Case, A.~W.; de Wit, Thierry; Malaspina, David; Bonnell, J.~W.; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Published by: \apjl Published on: jun YEAR: 2023 DOI: 10.3847/2041-8213/acd7f2 Parker Data Used; Solar wind; interplanetary turbulence; Magnetohydrodynamics; Space plasmas; Heliosphere; Alfven waves; 1534; 830; 1964; 1544; 711; 23; Astrophysics - Solar and Stellar Astrophysics; Physics - Fluid Dynamics; Physics - Geophysics; Physics - Plasma Physics; Physics - Space Physics |
|
The power spectrum of magnetic field fluctuations in the fast solar wind (V $_SW$ > 500 km s$^-1$) at magnetohydrodynamic scales is characterized by two different power laws on either side of a break frequency f $_b$. The low-frequency range at frequencies f smaller than f $_b$ is often viewed as the energy reservoir that feeds the turbulent cascade at f > f $_b$. At heliocentric distances r exceeding 60 solar radii (R $_s$), the power spectrum often has a 1/f scaling at f < f $_b$, i.e., the spectral index is close to -1. I ... Davis, Nooshin; Chandran, B.~D.~G.; Bowen, T.~A.; Badman, S.~T.; de Wit, Dudok; Chen, C.~H.~K.; Bale, S.~D.; Huang, Zesen; Sioulas, Nikos; Velli, Marco; Published by: \apj Published on: jun YEAR: 2023 DOI: 10.3847/1538-4357/acd177 Parker Data Used; Magnetohydrodynamics; Solar wind; interplanetary turbulence; 1964; 1534; 830; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
We analyze a merged Parker Solar Probe (PSP) and Solar Orbiter (SO) data set covering heliocentric distances 13 R $_\ensuremath\odot$ \ensuremath\lesssim R \ensuremath\lesssim 220 R $_\ensuremath\odot$ to investigate the radial evolution of power and spectral index anisotropy in the wavevector space of solar wind turbulence. Our results show that anisotropic signatures of turbulence display a distinct radial evolution when fast, V $_sw$ \ensuremath\geq 400 km s$^-1$, and slow, V $_sw$ \ensuremath\leq 400 km s$^-1$, wind stre ... Sioulas, Nikos; Velli, Marco; Huang, Zesen; Shi, Chen; Bowen, Trevor; Chandran, B.~D.~G.; Liodis, Ioannis; Davis, Nooshin; Bale, Stuart; Horbury, T.~S.; de Wit, Thierry; Larson, Davin; Stevens, Michael; Kasper, Justin; Owen, Christopher; Case, Anthony; Pulupa, Marc; Malaspina, David; Livi, Roberto; Goetz, Keith; Harvey, Peter; MacDowall, Robert; Bonnell, John; Published by: \apj Published on: jul YEAR: 2023 DOI: 10.3847/1538-4357/acc658 Parker Data Used; interplanetary turbulence; Solar wind; Space plasmas; Magnetohydrodynamics; Plasma astrophysics; 830; 1534; 1544; 1964; 1261; Physics - Space Physics; Astrophysics - High Energy Astrophysical Phenomena; Physics - Plasma Physics |
|
Parker Solar Probe: Four Years of Discoveries at Solar Cycle Minimum Launched on 12 Aug. 2018, NASA s Parker Solar Probe had completed 13 of its scheduled 24 orbits around the Sun by Nov. 2022. The mission s primary science goal is to determine the structure and dynamics of the Sun s coronal magnetic field, understand how the solar corona and wind are heated and accelerated, and determine what processes accelerate energetic particles. Parker Solar Probe returned a treasure trove of science data that far exceeded quality, significance, and quantity expectations, leading to a significant number ... Raouafi, N.~E.; Matteini, L.; Squire, J.; Badman, S.~T.; Velli, M.; Klein, K.~G.; Chen, C.~H.~K.; Matthaeus, W.~H.; Szabo, A.; Linton, M.; Allen, R.~C.; Szalay, J.~R.; Bruno, R.; Decker, R.~B.; Akhavan-Tafti, M.; Agapitov, O.~V.; Bale, S.~D.; Bandyopadhyay, R.; Battams, K.; Ber\vci\vc, L.; Bourouaine, S.; Bowen, T.~A.; Cattell, C.; Chandran, B.~D.~G.; Chhiber, R.; Cohen, C.~M.~S.; Amicis, R.; Giacalone, J.; Hess, P.; Howard, R.~A.; Horbury, T.~S.; Jagarlamudi, V.~K.; Joyce, C.~J.; Kasper, J.~C.; Kinnison, J.; Laker, R.; Liewer, P.; Malaspina, D.~M.; Mann, I.; McComas, D.~J.; Niembro-Hernandez, T.; Nieves-Chinchilla, T.; Panasenco, O.; y, Pokorn\; Pusack, A.; Pulupa, M.; Perez, J.~C.; Riley, P.; Rouillard, A.~P.; Shi, C.; Stenborg, G.; Tenerani, A.; Verniero, J.~L.; Viall, N.; Vourlidas, A.; Wood, B.~E.; Woodham, L.~D.; Woolley, T.; Published by: ßr Published on: feb YEAR: 2023 DOI: 10.1007/s11214-023-00952-4 Parker Data Used; Sun; Corona; Solar wind; plasma; magnetic fields; coronal mass ejections; parker solar probe; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
| 2022 |
|
In Situ Signature of Cyclotron Resonant Heating in the Solar Wind Bowen, Trevor; Chandran, Benjamin; Squire, Jonathan; Bale, Stuart; Duan, Die; Klein, Kristopher; Larson, Davin; Mallet, Alfred; McManus, Michael; Meyrand, Romain; Verniero, Jaye; Woodham, Lloyd; Published by: \prl Published on: oct YEAR: 2022 DOI: 10.1103/PhysRevLett.129.165101 |
|
In this Letter, we report observations of magnetic switchback (SB) features near 1 au using data from the Wind spacecraft. These features appear to be strikingly similar to the ones observed by the Parker Solar Probe mission closer to the Sun: namely, one- sided spikes (or enhancements) in the solar-wind bulk speed V that correlate/anticorrelate with the spikes seen in the radial- field component B $_ R $. In the solar-wind streams that we analyzed, these specific SB features near 1 au are associated with large-amplitude Alf ... Bourouaine, Sofiane; Perez, Jean; Raouafi, Nour; Chandran, Benjamin; Bale, Stuart; Velli, Marco; Published by: \apjl Published on: jun YEAR: 2022 DOI: 10.3847/2041-8213/ac67d9 Parker Data Used; Heliosphere; Solar wind; 711; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
Strong Perpendicular Velocity-space Diffusion in Proton Beams Observed by Parker Solar Probe The SWEAP instrument suite on Parker Solar Probe (PSP) has detected numerous proton beams associated with coherent, circularly polarized, ion-scale waves observed by PSP s FIELDS instrument suite. Measurements during PSP Encounters 4-8 revealed pronounced complex shapes in the proton velocity distribution functions (VDFs), in which the tip of the beam undergoes strong perpendicular diffusion, resulting in VDF level contours that resemble a hammerhead. We refer to these proton beams, with their attendant hammerhead fe ... Verniero, J.~L.; Chandran, B.~D.~G.; Larson, D.~E.; Paulson, K.; Alterman, B.~L.; Badman, S.; Bale, S.~D.; Bonnell, J.~W.; Bowen, T.~A.; de Wit, Dudok; Kasper, J.~C.; Klein, K.~G.; Lichko, E.; Livi, R.; McManus, M.~D.; Rahmati, A.; Verscharen, D.; Walters, J.; Whittlesey, P.~L.; Published by: \apj Published on: jan YEAR: 2022 DOI: 10.3847/1538-4357/ac36d5 Parker Data Used; 1544; 23; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
|
Improving the Alfv\ en Wave Solar Atmosphere Model Based on Parker Solar Probe Data In van der Holst et al. (2019), we modeled the solar corona and inner heliosphere of the first encounter of NASA s Parker Solar Probe (PSP) using the Alfv\ en Wave Solar atmosphere Model (AWSoM) with Air Force Data Assimilative Photospheric flux Transport- Global Oscillation Network Group magnetograms, and made predictions of the state of the solar wind plasma for the first encounter. AWSoM uses low-frequency Alfv\ en wave turbulence to address the coronal heating and acceleration. Here, we revise our simulations, by introdu ... van der Holst, B.; Huang, J.; Sachdeva, N.; Kasper, J.~C.; Manchester, W.~B.; Borovikov, D.; Chandran, B.~D.~G.; Case, A.~W.; Korreck, K.~E.; Larson, D.; Livi, R.; Stevens, M.; Whittlesey, P.; Bale, S.~D.; Pulupa, M.; Malaspina, D.~M.; Bonnell, J.~W.; Harvey, P.~R.; Goetz, K.; MacDowall, R.~J.; Published by: \apj Published on: feb YEAR: 2022 DOI: 10.3847/1538-4357/ac3d34 |
| 2021 |
|
Motivated by recent Parker Solar Probe (PSP) observations of switchbacks (abrupt, large-amplitude reversals in the radial magnetic field, which exhibit Alfv\ enic correlations), we examine the dynamics of large-amplitude Alfv\ en waves in the expanding solar wind. We develop an analytic model that makes several predictions: switchbacks should preferentially occur in regions where the solar wind plasma has undergone a greater expansion, the switchback fraction at radii comparable to PSP should be an increasing function of ... Mallet, Alfred; Squire, Jonathan; Chandran, Benjamin; Bowen, Trevor; Bale, Stuart; Published by: \apj Published on: sep YEAR: 2021 DOI: 10.3847/1538-4357/ac0c12 Alfven waves; Magnetohydrodynamics; Solar wind; Space plasmas; 23; 1964; 1534; 1544; Parker Data Used |
|
The near-Sun streamer belt solar wind: turbulence and solar wind acceleration The fourth orbit of Parker Solar Probe (PSP) reached heliocentric distances down to 27.9 R$_\ensuremath\odot$, allowing solar wind turbulence and acceleration mechanisms to be studied in situ closer to the Sun than previously possible. The turbulence properties were found to be significantly different in the inbound and outbound portions of PSP s fourth solar encounter, which was likely due to the proximity to the heliospheric current sheet (HCS) in the outbound period. Near the HCS, in the streamer belt wind, the turbulence ... 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: jun YEAR: 2021 DOI: "10.1051/0004-6361/202039872" |
|
Turbulent Generation of Magnetic Switchbacks in the Alfv\ enic Solar Wind One of the most important early results from the Parker Solar Probe (PSP) is the ubiquitous presence of magnetic switchbacks, whose origin is under debate. Using a three-dimensional direct numerical simulation of the equations of compressible magnetohydrodynamics from the corona to 40 solar radii, we investigate whether magnetic switchbacks emerge from granulation-driven Alfv\ en waves and turbulence in the solar wind. The simulated solar wind is an Alfv\ enic slow-solar- wind stream with a radial profile consistent with var ... Shoda, Munehito; Chandran, Benjamin; Cranmer, Steven; Published by: \apj Published on: jul YEAR: 2021 DOI: 10.3847/1538-4357/abfdbc Space plasmas; Solar wind; interplanetary turbulence; Parker Data Used; Magnetohydrodynamical simulations; Alfven waves; 1544; 1534; 830; 1966; 23; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics |
|
One of the striking observations from the Parker Solar Probe (PSP) spacecraft is the prevalence in the inner heliosphere of large amplitude, Alfv\ enic magnetic field reversals termed switchbacks. These $\delta B_R/B\sim \mathcal O (1$ ) fluctuations occur over a range of timescales and in patches separated by intervals of quiet, radial magnetic field. We use measurements from PSP to demonstrate that patches of switchbacks are localized within the extensions of plasma structures originating at the base of the corona. These ... Bale, S.~D.; Horbury, T.~S.; Velli, M.; Desai, M.~I.; Halekas, J.~S.; McManus, M.~D.; Panasenco, O.; Badman, S.~T.; Bowen, T.~A.; Chandran, B.~D.~G.; Drake, J.~F.; Kasper, J.~C.; Laker, R.; Mallet, A.; Matteini, L.; Phan, T.~D.; Raouafi, N.~E.; Squire, J.; Woodham, L.~D.; Woolley, T.; Published by: \apj Published on: dec YEAR: 2021 DOI: 10.3847/1538-4357/ac2d8c Parker Data Used; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
|
The Parker Solar Probe (PSP) routinely observes magnetic field deflections in the solar wind at distances less than 0.3 au from the Sun. These deflections are related to structures commonly called "switchbacks" (SBs), whose origins and characteristic properties are currently debated. Here, we use a database of visually selected SB intervals—and regions of solar wind plasma measured just before and after each SB—to examine plasma parameters, turbulent spectra from inertial to dissipation scales, and intermittency ... Martinovic, Mihailo; Klein, Kristopher; Huang, Jia; Chandran, Benjamin; Kasper, Justin; Lichko, Emily; Bowen, Trevor; Chen, Christopher; Matteini, Lorenzo; Stevens, Michael; Case, Anthony; Bale, Stuart; Published by: The Astrophysical Journal Published on: 05/2021 YEAR: 2021 DOI: 10.3847/1538-4357/abebe5 Parker Data Used; Space plasmas; interplanetary turbulence; Solar wind; 1544; 830; 1534; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
Between the base of the solar corona at $r=r_\textrm b$ and the Alfvén critical point at $r=r_\textrm A$, where $r$ is heliocentric distance, the solar-wind density decreases by a factor $ \mathop > \limits_∼ 10^5$, but the plasma temperature varies by a factor of only a few. In this paper, I show that such quasi-isothermal evolution out to $r=r_\textrm A$ is a generic property of outflows powered by reflection-driven Alfvén-wave (AW) turbulence, in which outward-propagating AWs partially reflect, and counter-propagating ... Published by: Journal of Plasma Physics Published on: 05/2021 YEAR: 2021 DOI: 10.1017/S0022377821000052 astrophysical plasmas; space plasma physics; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics; Parker Data Used |
|
How Alfvén waves energize the solar wind: heat versus work A growing body of evidence suggests that the solar wind is powered to a large extent by an Alfvén-wave (AW) energy flux. AWs energize the solar wind via two mechanisms: heating and work. We use high-resolution direct numerical simulations of reflection-driven AW turbulence (RDAWT) in a fast-solar-wind stream emanating from a coronal hole to investigate both mechanisms. In particular, we compute the fraction of the AW power at the coronal base ($P_\textrm AWb$) that is transferred to solar-wind particles via heating between ... Perez, Jean; Chandran, Benjamin; Klein, Kristopher; Martinovic, Mihailo; Published by: Journal of Plasma Physics Published on: 04/2021 YEAR: 2021 DOI: 10.1017/S0022377821000167 Parker Data Used; astrophysical plasmas; space plasma physics; plasma nonlinear phenomena; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
| 2020 |
|
Electron heat flux in the near-Sun environment \ Aims: We survey the electron heat flux observed by the Parker Solar Probe (PSP) in the near-Sun environment at heliocentric distances of 0.125-0.25 AU. \ Methods: We utilized measurements from the Solar Wind Electrons Alphas and Protons and FIELDS experiments to compute the solar wind electron heat flux and its components and to place these in context. \ Results: The PSP observations reveal a number of trends in the electron heat flux signatures near the Sun. The magnitude of the heat flux is anticorrelated with solar wind ... Halekas, J.; Whittlesey, P.; Larson, D.; McGinnis, D.; Bale, S.; Berthomier, M.; Case, A.; Chandran, B.; Kasper, J.; Klein, K.; Korreck, K.; Livi, R.; MacDowall, R.; Maksimovic, M.; al., et; Published by: Astronomy and Astrophysics Published on: jun YEAR: 2020 DOI: "10.1051/0004-6361/202039256" |
|
Constraining Ion-Scale Heating and Spectral Energy Transfer in Observations of Plasma Turbulence We perform a statistical study of the turbulent power spectrum at inertial and kinetic scales observed during the first perihelion encounter of the Parker Solar Probe. We find that often there is an extremely steep scaling range of the power spectrum just above the ion-kinetic scales, similar to prior observations at 1 A.U., with a power-law index of around -4 . Based on our measurements, we demonstrate that either a significant (\>50 \%) fraction of the total turbulent energy flux is dissipated in this range of scales ... Bowen, Trevor; Mallet, Alfred; Bale, Stuart; Bonnell, J.; Case, Anthony; Chandran, Benjamin; Chasapis, Alexandros; Chen, Christopher; Duan, Die; de Wit, Thierry; Goetz, Keith; Halekas, Jasper; Harvey, Peter; Kasper, J.; Korreck, Kelly; Larson, Davin; Livi, Roberto; MacDowall, Robert; Malaspina, David; McManus, Michael; Pulupa, Marc; Stevens, Michael; Whittlesey, Phyllis; Published by: Physical Review Letters Published on: 07/2020 YEAR: 2020 DOI: 10.1103/PhysRevLett.125.025102 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
|
In-situ Switchback Formation in the Expanding Solar Wind Recent near-Sun solar-wind observations from Parker Solar Probe have found a highly dynamic magnetic environment, permeated by abrupt radial-field reversals, or "switchbacks." We show that many features of the observed turbulence are reproduced by a spectrum of Alfv\ enic fluctuations advected by a radially expanding flow. Starting from simple superpositions of low-amplitude outward-propagating waves, our expanding-box compressible magnetohydrodynamic simulations naturally develop switchbacks because (i) the normalized am ... Squire, J.; Chandran, B.; Meyrand, R.; Published by: The Astrophysical Journal Published on: 03/2020 YEAR: 2020 DOI: 10.3847/2041-8213/ab74e1 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; 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 |
|
The Enhancement of Proton Stochastic Heating in the Near-Sun Solar Wind Stochastic heating (SH) is a nonlinear heating mechanism driven by the violation of magnetic moment invariance due to large-amplitude turbulent fluctuations producing diffusion of ions toward higher kinetic energies in the direction perpendicular to the magnetic field. It is frequently invoked as a mechanism responsible for the heating of ions in the solar wind. Here, we quantify for the first time the proton SH rate Q⊥ at radial distances from the Sun as close as 0.16 au, using measurements from the first tw ... Martinovic, Mihailo; Klein, Kristopher; Kasper, Justin; Case, Anthony; Korreck, Kelly; Larson, Davin; Livi, Roberto; Stevens, Michael; Whittlesey, Phyllis; Chandran, Benjamin; Alterman, Ben; Huang, Jia; Chen, Christopher; Bale, Stuart; Pulupa, Marc; Malaspina, David; Bonnell, John; Harvey, Peter; Goetz, Keith; de Wit, Thierry; MacDowall, Robert; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab527f Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Solar Probe Plus |
|
The Evolution and Role of Solar Wind Turbulence in the Inner Heliosphere The first two orbits of the Parker Solar Probe spacecraft have enabled the first in situ measurements of the solar wind down to a heliocentric distance of 0.17 au (or 36 R\ ⊙\ \ R⊙ ). Here, we present an analysis of this data to study solar wind turbulence at 0.17 au and its evolution out to 1 au. While many features remain similar, key differences at 0.17 au include increased turbulence energy levels by more than an order of magnitude, a magnetic field spectral index of -3/2 matching that of t ... Chen, C.; Bale, S.; Bonnell, J.; Borovikov, D.; Bowen, T.; Burgess, D.; Case, A.; Chandran, B.; de Wit, Dudok; Goetz, K.; Harvey, P.; Kasper, J.; Klein, K.; Korreck, K.; Larson, D.; Livi, R.; MacDowall, R.; Malaspina, D.; Mallet, A.; McManus, M.; Moncuquet, M.; Pulupa, M.; Stevens, M.; Whittlesey, P.; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab60a3 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; Solar Probe Plus |
|
Ion-scale Electromagnetic Waves in the Inner Heliosphere Understanding the physical processes in the solar wind and corona that actively contribute to heating, acceleration, and dissipation is a primary objective of NASA\textquoterights Parker Solar Probe (PSP) mission. Observations of circularly polarized electromagnetic waves at ion scales suggest that cyclotron resonance and wave-particle interactions are dynamically relevant in the inner heliosphere. A wavelet-based statistical study of circularly polarized events in the first perihelion encounter of PSP demonstrates that t ... Bowen, Trevor; Mallet, Alfred; Huang, Jia; Klein, Kristopher; Malaspina, David; Stevens, Michael; Bale, Stuart; Bonnell, J.; Case, Anthony; Chandran, Benjamin; Chaston, C.; Chen, Christopher; de Wit, Thierry; Goetz, Keith; Harvey, Peter; Howes, Gregory; Kasper, J.; Korreck, Kelly; Larson, Davin; Livi, Roberto; MacDowall, Robert; McManus, Michael; Pulupa, Marc; Verniero, J.; Whittlesey, Phyllis; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab6c65 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Space Physics; Solar Probe Plus |
|
Sharp Alfv\ enic Impulses in the Near-Sun Solar Wind Measurements of the near-Sun solar wind by the Parker Solar Probe have revealed the presence of large numbers of discrete Alfv\ enic impulses with an anti-sunward sense of propagation. These are similar to those previously observed near 1 au, in high speed streams over the Sun\textquoterights poles and at 60 solar radii. At 35 solar radii, however, they are typically shorter and sharper than seen elsewhere. In addition, these spikes occur in "patches" and there are also clear periods within the same stream when they do no ... Horbury, Timothy; Woolley, Thomas; Laker, Ronan; Matteini, Lorenzo; Eastwood, Jonathan; Bale, Stuart; Velli, Marco; Chandran, Benjamin; Phan, Tai; Raouafi, Nour; Goetz, Keith; Harvey, Peter; Pulupa, Marc; Klein, K.; de Wit, Thierry; Kasper, Justin; Korreck, Kelly; Case, A.; Stevens, Michael; Whittlesey, Phyllis; Larson, Davin; MacDowall, Robert; Malaspina, David; Livi, Roberto; Published by: The Astrophysical Journal Supplement Series Published on: 02/2020 YEAR: 2020 DOI: 10.3847/1538-4365/ab5b15 |
| 2019 |
|
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 |
|
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 |
|
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 |
|
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 |
| 2018 |
|
Parametric instability, inverse cascade and the range of solar-wind turbulence In this paper, weak-turbulence theory is used to investigate the nonlinear evolution of the parametric instability in three-dimensional low-β plasmas at wavelengths much greater than the ion inertial length under the assumption that slow magnetosonic waves are strongly damped. It is shown analytically that the parametric instability leads to an inverse cascade of Alfv\ en wave quanta, and several exact solutions to the wave kinetic equations are presented. The main results of the paper concern the parametric decay of Alf ... Published by: Journal of Plasma Physics Published on: 02/2018 YEAR: 2018 DOI: 10.1017/S0022377818000016 astrophysical plasmas; Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; plasma nonlinear phenomena; plasma waves; Solar Probe Plus |
| 2016 |
|
The FIELDS Instrument Suite for Solar Probe Plus NASA\textquoterights Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument conce ... Bale, S.; Goetz, K.; Harvey, P.; Turin, P.; Bonnell, J.; de Wit, T.; Ergun, R.; MacDowall, R.; Pulupa, M.; Andre, M.; Bolton, M.; Bougeret, J.-L.; Bowen, T.; Burgess, D.; Cattell, C.; Chandran, B.; Chaston, C.; Chen, C.; Choi, M.; Connerney, J.; Cranmer, S.; Diaz-Aguado, M.; Donakowski, W.; Drake, J.; Farrell, W.; Fergeau, P.; Fermin, J.; Fischer, J.; Fox, N.; Glaser, D.; Goldstein, M.; Gordon, D.; Hanson, E.; Harris, S.; Hayes, L.; Hinze, J.; Hollweg, J.; Horbury, T.; Howard, R.; Hoxie, V.; Jannet, G.; Karlsson, M.; Kasper, J.; Kellogg, P.; Kien, M.; Klimchuk, J.; Krasnoselskikh, V.; Krucker, S.; Lynch, J.; Maksimovic, M.; Malaspina, D.; Marker, S.; Martin, P.; Martinez-Oliveros, J.; McCauley, J.; McComas, D.; McDonald, T.; Meyer-Vernet, N.; Moncuquet, M.; Monson, S.; Mozer, F.; Murphy, S.; Odom, J.; Oliverson, R.; Olson, J.; Parker, E.; Pankow, D.; Phan, T.; Quataert, E.; Quinn, T.; Ruplin, S.; Salem, C.; Seitz, D.; Sheppard, D.; Siy, A.; Stevens, K.; Summers, D.; Szabo, A.; Timofeeva, M.; Vaivads, A.; Velli, M.; Yehle, A.; Werthimer, D.; Wygant, J.; Published by: Space Science Reviews Published on: 12/2016 YEAR: 2016 DOI: 10.1007/s11214-016-0244-5 Coronal heating; Parker Data Used; parker solar probe; Solar Probe Plus |
|
EVOLUTION OF THE PROTON VELOCITY DISTRIBUTION DUE TO STOCHASTIC HEATING IN THE NEAR-SUN SOLAR WIND We investigate how the proton distribution function evolves when the protons undergo stochastic heating by strong, low-frequency, Alfv\ en-wave turbulence under the assumption that β is small. We apply our analysis to protons undergoing stochastic heating in the supersonic fast solar wind and obtain proton distributions at heliocentric distances ranging from 4 to 30 solar radii. We find that the proton distribution develops non-Gaussian structure with a flat core and steep tail. For r\gt 5 RS, the proton distr ... Klein, Kristopher; Chandran, Benjamin; Published by: The Astrophysical Journal Published on: 03/2016 YEAR: 2016 DOI: 10.3847/0004-637X/820/1/47 Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics - Plasma Physics; plasmas; Solar Probe Plus; Solar wind; turbulence; waves |
| 2015 |
|
The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on Solar Probe Plus is a four sensor instrument suite that provides complete measurements of the electrons and ionized helium and hydrogen that constitute the bulk of solar wind and coronal plasma. SWEAP consists of the Solar Probe Cup (SPC) and the Solar Probe Analyzers (SPAN). SPC is a Faraday Cup that looks directly at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic ... Kasper, Justin; Abiad, Robert; Austin, Gerry; Balat-Pichelin, Marianne; Bale, Stuart; Belcher, John; Berg, Peter; Bergner, Henry; Berthomier, Matthieu; Bookbinder, Jay; Brodu, Etienne; Caldwell, David; Case, Anthony; Chandran, Benjamin; Cheimets, Peter; Cirtain, Jonathan; Cranmer, Steven; Curtis, David; Daigneau, Peter; Dalton, Greg; Dasgupta, Brahmananda; DeTomaso, David; Diaz-Aguado, Millan; Djordjevic, Blagoje; Donaskowski, Bill; Effinger, Michael; Florinski, Vladimir; Fox, Nichola; Freeman, Mark; Gallagher, Dennis; Gary, Peter; Gauron, Tom; Gates, Richard; Goldstein, Melvin; Golub, Leon; Gordon, Dorothy; Gurnee, Reid; Guth, Giora; Halekas, Jasper; Hatch, Ken; Heerikuisen, Jacob; Ho, George; Hu, Qiang; Johnson, Greg; Jordan, Steven; Korreck, Kelly; Larson, Davin; Lazarus, Alan; Li, Gang; Livi, Roberto; Ludlam, Michael; Maksimovic, Milan; McFadden, James; Marchant, William; Maruca, Bennet; McComas, David; Messina, Luciana; Mercer, Tony; Park, Sang; Peddie, Andrew; Pogorelov, Nikolai; Reinhart, Matthew; Richardson, John; Robinson, Miles; Rosen, Irene; Skoug, Ruth; Slagle, Amanda; Steinberg, John; Stevens, Michael; Szabo, Adam; Taylor, Ellen; Tiu, Chris; Turin, Paul; Velli, Marco; Webb, Gary; Whittlesey, Phyllis; Wright, Ken; Wu, S.; Zank, Gary; Published by: Space Science Reviews Published on: 10/2015 YEAR: 2015 DOI: 10.1007/s11214-015-0206-3 Acceleration; Corona; Heating; Parker Data Used; Solar Probe Plus; Solar wind plasma; SWEAP |
|
Intermittency and Alignment in Strong RMHD Turbulence Chandran, B.~D.~G.; Schekochihin, A.~A.; Mallet, A.; Published by: \apj Published on: 07/2015 YEAR: 2015 DOI: 10.1088/0004-637X/807/1/39 Parker Data Used; magnetohydrodynamics: MHD; plasmas; Solar wind; Sun: chromosphere; Sun: corona; turbulence; Astrophysics - Solar and Stellar Astrophysics; Physics - Space Physics |
|
A MODIFIED VERSION OF TAYLOR\textquoterightS HYPOTHESIS FOR SOLAR PROBE PLUS OBSERVATIONS The Solar Probe Plus (SPP) spacecraft will explore the near-Sun environment, reaching heliocentric distances less than 10 R☉ . Near Earth, spacecraft measurements of fluctuating velocities and magnetic fields taken in the time domain are translated into information about the spatial structure of the solar wind via Taylor\textquoterights \textquotedblleftfrozen turbulence\textquotedblright hypothesis. Near the perihelion of SPP, however, the solar-wind speed is comparable to the Alfv\ en speed, and Taylor\text ... Klein, Kristopher; Perez, Jean; Verscharen, Daniel; Mallet, Alfred; Chandran, Benjamin; Published by: The Astrophysical Journal Published on: 03/2015 YEAR: 2015 DOI: 10.1088/2041-8205/801/1/L18 Astrophysics - Solar and Stellar Astrophysics; Parker Data Used; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; Sun: corona; turbulence |
| 2013 |
|
Stochastic Heating, Differential Flow, and the Alpha-to-proton Temperature Ratio in the Solar Wind Chandran, B.~D.~G.; Verscharen, D.; Quataert, E.; Kasper, J.~C.; Isenberg, P.~A.; Bourouaine, S.; Published by: \apj Published on: 10/2013 YEAR: 2013 DOI: 10.1088/0004-637X/776/1/45 Parker Data Used; plasmas; Solar wind; Sun: corona; turbulence; waves; Astrophysics - Solar and Stellar Astrophysics; Physics - Plasma Physics; Physics - Space Physics |
|
Perez, Jean; Chandran, Benjamin; Published by: \apj Published on: 10/2013 YEAR: 2013 DOI: 10.1088/0004-637X/776/2/124 Parker Data Used; magnetohydrodynamics: MHD; Solar wind; Sun: corona; turbulence; waves |
1
