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Related papers: Angular momentum transport in a multicomponent sol…

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The effect of solar rotation on the proton-alpha differential flow speed, $v_{\alpha p}$, and consequently on the angular momentum transport in the solar wind, is explored. It is found that the force introduced by the azimuthal components…

Astrophysics · Physics 2011-02-11 Bo Li , Shadia Rifai Habbal , Xing Li

We study correlations of the temperature ratio (which is an indicator for perpendicular ion heating) and the differential flow of the alpha particles with the power of transverse fluctuations that have wave numbers between 0.01 and 0.1…

Solar and Stellar Astrophysics · Physics 2011-11-14 S. Bourouaine , E. Marsch , F. M. Neubauer

Proton and alpha particle collisional transport coefficients (isotropization, relative deceleration frequencies and heating rates) at 1 AU are quantified using the WIND/SWE data. In agreement with previous studies the ion-ion Coulomb…

Space Physics · Physics 2016-08-04 Petr Hellinger

Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure-anisotropy-driven instabilities such as the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Sofiane Bourouaine , Daniel Verscharen , Benjamin D. G. Chandran , Bennett A. Maruca , Justin C. Kasper

The classic Weber-Davis model of the solar wind is reconsidered by incorporating alpha particles and by allowing the solar wind to flow out of the equatorial plane in an axisymmetrical configuration. In the ion momentum equations of the…

Astrophysics · Physics 2007-05-23 Bo Li , Xing Li

Protons (ionized hydrogen) in the solar wind frequently exhibit distinct temperatures ($T_{\perp p}$ and $T_{\parallel p}$) perpendicular and parallel to the plasma's background magnetic-field. Numerous prior studies of the interplanetary…

How the solar wind is accelerated to its supersonic speed is intimately related to how it is heated. Mechanisms based on ion-cyclotron resonance have been successful in explaining a large number of observations, those concerning the…

Solar and Stellar Astrophysics · Physics 2012-12-03 Bo Li , Shadia Rifai Habbal

A variety of nonthermal characteristics like kinetic, e.g., temperature, anisotropies and suprathermal populations (enhancing the high energy tails of the velocity distributions) are revealed by the in-situ observations in the solar wind…

Solar and Stellar Astrophysics · Physics 2016-12-06 S. M. Shaaban , M. Lazar , S. Poedts , A. Elhanbaly

Remote sensing observations of coronal holes show that heavy ions are hotter than protons and their temperature is anisotropic. In-situ observations of fast solar wind streams provide direct evidence for turbulent Alfv\'en wave spectrum,…

Solar and Stellar Astrophysics · Physics 2015-06-22 N. Ozak , L. Ofman , A. -F. Viñas

In-situ observations of the solar wind (SW) plasma from 0.29 to 1AU show that the protons and alpha particles are often non-Maxwellian, with evidence of kinetic instabilities, temperature anisotropies, differential ion streaming, and…

Space Physics · Physics 2019-05-15 Leon Ofman

Over decades of solar wind observations, heavy ions have been observed to have a higher temperature and flow faster than protons in the solar corona and heliosphere. Remote observations have largely been limited to the low corona ($<…

The fast solar wind is a collisionless plasma permeated by plasma waves on many different scales. A plasma wave represents the natural interplay between the periodic changes of the electromagnetic field and the associated coherent motions…

Space Physics · Physics 2011-07-29 Daniel Verscharen , Eckart Marsch

A semi-empirical, axisymmetric model of the solar minimum corona is developed by solving the equations for conservation of mass and momentum with prescribed anisotropic temperature distributions. In the high-latitude regions, the proton…

Astrophysics · Physics 2009-11-10 Alberto M. Vasquez , Adriaan A. van Ballegooijen , John C. Raymond

An accurate assessment of the Sun's angular momentum (AM) loss rate is an independent constraint for models that describe the rotation evolution of Sun-like stars. In-situ measurements of the solar wind taken by Parker Solar Probe (PSP), at…

Correlations are studied between the power density of transverse waves having frequencies between $0.01$ and $1$ normalized to the proton gyrofrequency in the plasma frame and the ratio of the perpendicular and parallel temperature of the…

Solar and Stellar Astrophysics · Physics 2010-08-04 Sofiane Bourouaine , Eckart Marsch , Fritz M. Neubauer

We perform 2.5D hybrid simulations with massless fluid electrons and kinetic particle-in-cell ions to study the temporal evolution of ion temperatures, temperature anisotropies and velocity distribution functions in relation to the…

Plasma Physics · Physics 2015-06-18 Y. G. Maneva , Adolfo F. Viñas , Pablo S. Moya , R. Wicks , S. Poedts

Where and under what conditions the transfer of energy between electromagnetic fields and particles takes place in the solar wind remains an open question. We investigate the conditions that promote the growth of kinetic instabilities…

We perform 2.5D hybrid simulations to investigate the origin and evolution of relative drift speeds between protons and $\alpha$ particles in the collisionless turbulent low-$\beta$ solar wind plasma. We study the generation of differential…

Space Physics · Physics 2015-06-11 Y. G. Maneva , L. Ofman , A. Viñas

Hybrid Vlasov-Maxwell simulations are employed to investigate the role of kinetic effects in a two-dimensional turbulent multi-ion plasma, composed of protons, alpha particles and fluid electrons. In the typical conditions of the solar-wind…

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