PSP Bibliography



Found 12 entries in the Bibliography.


Showing entries from 1 through 12


2020

The evolution of inverted magnetic fields through the inner heliosphereABSTRACT

Local inversions are often observed in the heliospheric magnetic field (HMF), but their origins and evolution are not yet fully understood. Parker Solar Probe has recently observed rapid, Alfv\ enic, HMF inversions in the inner heliosphere, known as \textquoterightswitchbacks\textquoteright, which have been interpreted as the possible remnants of coronal jets. It has also been suggested that inverted HMF may be produced by near-Sun interchange reconnection; a key process in mechanisms proposed for slow solar wind release. ...

Macneil, Allan; Owens, Mathew; Wicks, Robert; Lockwood, Mike; Bentley, Sarah; Lang, Matthew;

YEAR: 2020     DOI: 10.1093/mnras/staa951

Astrophysics - Solar and Stellar Astrophysics; magnetic fields; parker solar probe; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; Sun: heliosphere

Highly Alfv\ enic slow solar wind at 0.3 au during a solar minimum: Helios insights for Parker Solar Probe and Solar Orbiter

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.;

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;

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

2018

Investigating the Effect of IMF Path Length on Pitch-angle Scattering of Strahl within 1 au

Strahl is the strongly field-aligned, beam-like population of electrons in the solar wind. Strahl width is observed to increase with distance from the Sun, and hence strahl electrons must be subject to in-transit scattering effects. Different energy relations have been both observed and modeled for both strahl width and the width increase with radial distance. Thus, there is much debate regarding what mechanism(s) scatter strahl. In this study, we use a novel method to investigate strahl evolution within 1 au by estimatin ...

Graham, G.; Rae, I.; Owen, C.; Walsh, A.;

YEAR: 2018     DOI: 10.3847/1538-4357/aaaf1b

parker solar probe; plasmas; scattering; Solar Probe Plus; Solar wind; Sun: heliosphere

2017

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.;

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

2016

MEASURING COLLISIONLESS DAMPING IN HELIOSPHERIC PLASMAS USING FIELD\textendashPARTICLE CORRELATIONS

An innovative field-particle correlation technique is proposed that uses single-point measurements of the electromagnetic fields and particle velocity distribution functions to investigate the net transfer of energy from fields to particles associated with the collisionless damping of turbulent fluctuations in weakly collisional plasmas, such as the solar wind. In addition to providing a direct estimate of the local rate of energy transfer between fields and particles, it provides vital new information about the distribut ...

Klein, K.; Howes, G.;

YEAR: 2016     DOI: 10.3847/2041-8205/826/2/L30

Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; turbulence; waves

SOLAR WIND COLLISIONAL AGE FROM A GLOBAL MAGNETOHYDRODYNAMICS SIMULATION

Simple estimates of the number of Coulomb collisions experienced by the interplanetary plasma to the point of observation, I.e., the \textquotedblleftcollisional age\textquotedblright, can be usefully employed in the study of non-thermal features of the solar wind. Usually these estimates are based on local plasma properties at the point of observation. Here we improve the method of estimation of the collisional age by employing solutions obtained from global three-dimensional magnetohydrodynamics simulations. This enable ...

Chhiber, R; Usmanov, AV; Matthaeus, WH; Goldstein, ML;

YEAR: 2016     DOI: 10.3847/0004-637X/821/1/34

magnetohydrodynamics: MHD; methods: numerical; parker solar probe; plasmas; scattering; Solar Probe Plus; Solar wind; turbulence

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;

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

ION-SCALE TURBULENCE IN THE INNER HELIOSPHERE: RADIAL DEPENDENCE

The evolution of the ion-scale plasma turbulence in the inner heliosphere is studied by associating the plasma parameters for hybrid-code turbulence simulations to the radial distance from the Sun via a Solar wind model based mapping procedure. Using a mapping based on a one-dimensional solar wind expansion model, the resulting ion-kinetic scale turbulence is related to the solar wind distance from the Sun. For this purpose the mapping is carried out for various values of ion beta that correspond to the heliocentric dista ...

sel, H.; Motschmann, U.; üchner, J.; Narita, Y.; Nariyuki, Y.;

YEAR: 2015     DOI: 10.1088/0004-637X/812/2/175

parker solar probe; plasmas; Solar Probe Plus; Solar wind; turbulence; waves

KINETIC EVOLUTION OF CORONAL HOLE PROTONS BY IMBALANCED ION-CYCLOTRON WAVES: IMPLICATIONS FOR MEASUREMENTS BY SOLAR PROBE PLUS

We extend the kinetic guiding-center model of collisionless coronal hole protons presented in Isenberg \& Vasquez to consider driving by imbalanced spectra of obliquely propagating ion-cyclotron waves. These waves are assumed to be a small by-product of the imbalanced turbulent cascade to high perpendicular wavenumber, and their total intensity is taken to be 1\% of the total fluctuation energy. We also extend the kinetic solutions for the proton distribution function in the resulting fast solar wind to heliocentric d ...

Isenberg, Philip; Vasquez, Bernard;

YEAR: 2015     DOI: 10.1088/0004-637X/808/2/119

parker solar probe; plasmas; Solar Probe Plus; Solar wind; Sun: corona; turbulence; waves

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;

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

2014

THE VIOLATION OF THE TAYLOR HYPOTHESIS IN MEASUREMENTS OF SOLAR WIND TURBULENCE

Motivated by the upcoming Solar Orbiter and Solar Probe Plus missions, qualitative and quantitative predictions are made for the effects of the violation of the Taylor hypothesis on the magnetic energy frequency spectrum measured in the near-Sun environment. The synthetic spacecraft data method is used to predict observational signatures of the violation for critically balanced Alfv\ enic turbulence or parallel fast/whistler turbulence. The violation of the Taylor hypothesis can occur in the slow flow regime, leading to a ...

Klein, K.; Howes, G.; TenBarge, J.;

YEAR: 2014     DOI: 10.1088/2041-8205/790/2/L20

Astrophysics - Solar and Stellar Astrophysics; parker solar probe; Physics - Plasma Physics; Physics - Space Physics; plasmas; Solar Probe Plus; Solar wind; turbulence; waves



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