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Related papers: Modeling Solar Wind Variations over an 11-yr Cycle…

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Although it is widely accepted that photospheric motions provide the energy source and that the magnetic field must play a key role in the process, the detailed mechanisms responsible for heating the Sun's corona and accelerating the solar…

Solar and Stellar Astrophysics · Physics 2016-01-12 Roberto Lionello , Marco Velli , Cooper Downs , Jon A. Linker , Zoran Mikić

The solar wind upstream of Mars's bow shock can be described in terms of Alfv\'enic turbulence, with an incompressible energy cascade rate of $10^{-17}$ J m$^{-3}$ s$^{-1}$ at magnetohydrodynamics (MHD) scales. The solar wind has more…

Solar and Stellar Astrophysics · Physics 2024-06-26 Norberto Romanelli , Christopher M. Fowler , Gina A. DiBraccio , Jared R. Espley , Jasper S. Halekas

We want to study the connections between the magnetic field generated inside the Sun and the solar wind impacting Earth, especially the influence of north-south asymmetry on the magnetic and velocity fields. We study a solar-like 11-year…

Solar and Stellar Astrophysics · Physics 2018-09-11 Barbara Perri , Allan Sacha Brun , Victor Réville , Antoine Strugarek

Empirical solar wind speed models play an important role in enabling space weather forecasting with low computational cost. Among these, one model called WS model is based on the asymptotic expansion factor. However, it is known that it…

Solar and Stellar Astrophysics · Physics 2026-01-30 Kyogo Tokoro , Munehito Shoda , Shinsuke Imada

Cool stars at giant and supergiant evolutionary phases present low velocity and high density winds, responsible for the observed high mass-loss rates. Although presenting high luminosities, radiation pressure on dust particles is not…

Astrophysics · Physics 2009-11-11 D. Falceta-Goncalves , A. A. Vidotto , V. Jatenco-Pereira

Four decades have gone by since the discovery that the solar wind at 1 AU seems to exist in two relatively distinct states: slow and fast. There is still no universal agreement concerning the primary physical cause of this apparently…

Astrophysics · Physics 2007-05-23 Steven R. Cranmer

Alfv\'en waves are known to be important carriers of magnetic energy that could play a role in coronal heating and/or solar wind acceleration. As these waves are efficient energy carriers, how they are dissipated still remains one of the…

Solar and Stellar Astrophysics · Physics 2025-07-22 Anmol Kumar , Thomas A. Howson , Paolo Pagano , Ineke De Moortel

By explicitly taking into account effects of Alfven waves, I derive from a simple energetics argument a fundamental relation which predicts solar wind (SW) speeds in the vicinity of the earth from physical properties on the sun. Kojima et…

Astrophysics · Physics 2009-11-11 Takeru K. Suzuki

Observations of stellar rotation show that low-mass stars lose angular momentum during the main sequence. We simulate the winds of Sun-like stars with a range of rotation rates, covering the fast and slow magneto-rotator regimes, including…

We study the propagation, reflection, and turbulent dissipation of Alfven waves in coronal holes and the solar wind. We start with the Heinemann-Olbert equations, which describe non-compressive magnetohydrodynamic fluctuations in an…

Solar and Stellar Astrophysics · Physics 2014-11-20 Benjamin D. G. Chandran , Joseph V. Hollweg

During Parker Solar Probe's first orbit, the solar wind plasma has been observed in situ closer than ever before, the perihelion on November 6th 2018 revealing a flow that is constantly permeated by large amplitude Alfv\'enic fluctuations.…

We present multicomponent solar wind models self-consistently incorporating the contribution from dissipationless, monochromatic, finite-wavelength (non-WKB), hydromagnetic, toroidal Alfv\'en waves, which are coupled to the flow only…

Astrophysics · Physics 2009-11-13 Bo Li , Xing Li

The heating and acceleration of the solar wind remains one of the fundamental unsolved problems in heliophysics. It is usually observed that the proton temperature $T_i$ is highly correlated with the solar wind speed $V_{SW}$, while the…

We present numerical simulations of reduced magnetohydrodynamic (RMHD) turbulence in a magnetic flux tube at the center of a polar coronal hole. The model for the background atmosphere is a solution of the momentum equation, and includes…

Solar and Stellar Astrophysics · Physics 2016-04-27 A. A. van Ballegooijen , M. Asgari-Targhi

Alfv\'en waves are widely believed to play an important role in the transport of energy from the solar photosphere to the corona through the partially ionized chromosphere. In previous work, the properties of torsional Alfv\'en waves were…

Solar and Stellar Astrophysics · Physics 2026-03-25 Roberto Soler

The solar wind is the extension of the Sun's hot and ionized corona, and it exists in a state of continuous expansion into interplanetary space. The radial distance at which the wind's outflow speed exceeds the phase speed of Alfvenic and…

We review our recent results of Alfven wave-driven winds. First, we present the result of a self-consistent 1D MHD simulations for solar winds from the photosphere to interplanetary region. Here, we emphasize the importance of the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Takeru K. Suzuki

Alfv\'enic motions are ubiquitous in the solar atmosphere and their observed properties are closely linked to those of photospheric p-modes. However, it is still unclear how a predominantly acoustic wave driver can produce these transverse…

Solar and Stellar Astrophysics · Physics 2023-05-31 Samuel Skirvin , Yuhang Gao , Tom Van Doorsselaere

The solar wind is highly structured in fast and slow flows. These two dynamical regimes remarkably differ not only for the average values of magnetic field and plasma parameters but also for the type of fluctuations they transport. Fast…

Solar and Stellar Astrophysics · Physics 2017-08-04 R. Bruno , D. Telloni , D. DeIure , E. Pietropaolo

Axford and McKenzie [1992] suggested that the energy released in impulsive reconnection events generates high frequency Alfv\'en waves. The kinetic equation for spectral energy density of waves is derived in the random phase approximation.…

Space Physics · Physics 2007-05-23 A. A. Galeev A. M. Sadovski