scholarly journals How important are the alpha-proton relative drift and the electron heat flux for the proton heating of the solar wind in the inner heliosphere?

2014 ◽  
Vol 119 (7) ◽  
pp. 5210-5219 ◽  
Author(s):  
Joseph E. Borovsky ◽  
S. Peter Gary
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat ◽  
Inner Heliosphere

scholarly journals The electron heat flux in the polar solar wind: Ulysses observations

1999 ◽  
Vol 26 (14) ◽  
pp. 2129-2132 ◽  
Author(s):  
Earl E. Scime ◽  
Allen E. Badeau ◽  
J. E. Littleton
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat

Regulation of the solar wind electron heat flux from 1 to 5 AU: Ulysses observations

1994 ◽  
Vol 99 (A12) ◽  
pp. 23401 ◽  
Author(s):  
Earl E. Scime ◽  
Samuel J. Bame ◽  
William C. Feldman ◽  
S. Peter Gary ◽  
John L. Phillips ◽  
...  
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat ◽  
Solar Wind Electron

Electron heat flux constraints in the solar wind

1999 ◽  
Vol 6 (6) ◽  
pp. 2607-2612 ◽  
Author(s):  
S. Peter Gary ◽  
Ruth M. Skoug ◽  
William Daughton
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat

Bidirectional solar wind electron heat flux and hemispherically symmetric polar rain

1986 ◽  
Vol 91 (A10) ◽  
pp. 11352 ◽  
Author(s):  
J. T. Gosling ◽  
D. N. Baker ◽  
S. J. Bame ◽  
R. D. Zwickl
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat ◽  
Polar Rain ◽  
Solar Wind Electron

Skew-Kappa distribution functions & whistler-heat flux instability in the solar wind

2021 ◽  
Author(s):  
Bea Zenteno-Quinteros ◽  
Adolfo F. Viñas ◽  
Pablo S. Moya
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Velocity ◽  
Marginal Stability ◽  
Threshold Condition ◽  
Kappa Distribution ◽  
Particle Interactions ◽  
Whistler Mode ◽  
Electron Heat ◽  
Wave Particle Interactions

<p>Electron velocity distributions in the solar wind are known to have field-aligned skewness, which has been observationally characterized by the presence of secondary populations such as the halo and strahl electron components. This non-thermal feature provides energy for the excitation of electromagnetic instabilities that may play a role in regulating the electron heat flux in the solar wind by wave-particle interactions. Among the wave modes excited in regulating the electron non-thermal features is the whistler-mode and its so-called whistler heat-flux instability (WHFI). In this work, we use kinetic linear theory to analyze the stability of the WHFI in a solar wind like plasma where the electrons are described as a single population modeled by a Kappa distribution to which an asymmetry term has been added. We solve the dispersion relation numerically for the parallel propagating whistler-mode and study its linear stability for different plasma parameters. We also show the marginal stability thresholds for this instability as a function of the electron beta and the parallel electron heat flux and present a threshold condition for instability that can be modeled to compare with observational data. The principal result is that the WHFI can develop in this system; however, the heat flux parameter is not a good predictor of how unstable this wave mode will be. This is because different plasma states, with different stability to WHFI, can have the same initial heat flux. Thus, systems with high <img title="This is the rendered form of the equation. You can not edit this directly. Right click will give you the option to save the image, and in most browsers you can drag the image onto your desktop or another program." src="https://latex.codecogs.com/gif.latex?q_%7B%5Cparallel%20e%7D/q_0"> can be stable enough to WHFI so that it cannot effectively modify the heat flux values through wave-particle interactions</p>

Role of Whistler Waves in Regulation of the Heat Flux in the Solar Wind

2020 ◽  
Author(s):  
Ilya Kuzichev ◽  
Ivan Vasko ◽  
Angel Rualdo Soto-Chavez ◽  
Anton Artemyev
Keyword(s):  
Magnetic Field ◽  
Heat Flux ◽  
Solar Wind ◽  
Particle Interaction ◽  
Solar Wind Plasma ◽  
Whistler Waves ◽  
Particle In Cell ◽  
Electron Heat ◽  
Background Magnetic Field ◽  
Institute Of Technology

<p>The electron heat flux is one of the leading terms in energy flow processes in the collisionless or weakly-collisional solar wind plasma. The very first observations demonstrated that the collisional Spitzer-HÓ“rm law could not describe the heat flux in the solar wind well. In particular, in-situ observations at 1AU showed that the heat flux was suppressed below the collisional value. Different mechanisms of the heat flux regulation in the solar wind were proposed. One of these possible mechanisms is the wave-particle interaction with whistler-mode waves produced by the so-called whistler heat flux instability (WHFI). This instability operates in plasmas with at least two counter-streaming electron populations. Recent observations indicated that the WHFI operates in the solar wind producing predominantly quasi-parallel whistler waves with the amplitudes up to several percent of the background magnetic field. But whether such whistler waves can regulate the heat flux still remained an open question.</p><p>We present the results of simulation of the whistler generation and nonlinear evolution using the 1D full Particle-in-Cell code TRISTAN-MP. This code models self-consistent dynamics of ions and two counter-streaming electron populations:  warm (core) electrons and hot (halo) electrons. We performed two sets of simulations. In the first set, we studied the wave generation for the classical WHFI, so both core and halo electron distributions were taken to be isotropic. We found a positive correlation between the plasma beta and the saturated wave amplitude. For the heat flux, the correlation changes from positive to a negative one at some value of the heat flux. The observed wave amplitudes and correlations are consistent with the observations. Our calculations show that the electron heat flux does not change substantially in the course of the WHFI development; hence such waves are unlikely to contribute significantly to the heat flux regulation in the solar wind.</p><p>The classical WHFI drives only those whistler waves that propagate along the halo electron drift direction (consequently, parallel with respect to background magnetic field). Such waves interact resonantly with electrons that move in the opposite direction; hence, only a relatively small fraction of hot halo electrons is affected by these waves. On the contrary, anti-parallel whistler waves would interact with a substantial fraction of halo electrons. Thus, they could influence the heat flux more significantly. To test this hypothesis, we performed the second set of simulations with anisotropic halo electrons. Anisotropic distribution drives both parallel and anti-parallel waves. Our calculations demonstrate that anti-parallel whistler waves can decrease the heat flux. This indicates that the waves generated via combined whistler anisotropy and heat flux instabilities might contribute to regulation of the heat flux in the solar wind.</p><p>The work was supported by NSF grant 1502923. I. Kuzichev would also like to acknowledge the support of the RBSPICE Instrument project by JHU/APL sub-contract 937836 to the New Jersey Institute of Technology under NASA Prime contract NAS5-01072. Computational facility: Cheyenne supercomputer (doi:10.5065/D6RX99HX) provided by NCAR’s Computational and Information Systems Laboratory, sponsored by NSF</p>

Electron heat flux instabilities in the solar wind

1975 ◽  
Vol 2 (3) ◽  
pp. 79-82 ◽  
Author(s):  
S. Peter Gary ◽  
W. C. Feldman ◽  
D. W. Forslund ◽  
M. D. Montgomery
Keyword(s):  
Heat Flux ◽  
Solar Wind ◽  
Electron Heat
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