English
Related papers

Related papers: An approximate analytic solution to the coupled pr…

200 papers

The origins of the hot solar corona and the supersonically expanding solar wind are still the subject of much debate. This paper summarizes some of the essential ingredients of realistic and self-consistent models of solar wind…

Solar and Stellar Astrophysics · Physics 2015-05-19 Steven R. Cranmer

We solve the problem of propagation and dissipation of Alfvenic turbulence in a model solar atmosphere consisting of a static photosphere and chromosphere, transition region, and open corona and solar wind, using a phenomenological model…

Astrophysics · Physics 2011-02-11 A. Verdini , M. Velli

We develop a 1D solar-wind model that includes separate energy equations for the electrons and protons, proton temperature anisotropy, collisional and collisionless heat flux, and an analytical treatment of low-frequency, reflection-driven,…

Solar and Stellar Astrophysics · Physics 2012-01-10 Benjamin D. G. Chandran , Timothy J. Dennis , Eliot Quataert , Stuart D. Bale

Protons in the solar corona and heliosphere exhibit anisotropic velocity distributions, violation of magnetic moment conservation, and a general lack of thermal equilibrium with the other particle species. There is no agreement about the…

Solar and Stellar Astrophysics · Physics 2015-06-19 Steven R. Cranmer

In this work we analyze plasma and magnetic field data provided by the Parker Solar Probe (\emph{PSP}) and Solar Orbiter (\emph{SO}) missions to investigate the radial evolution of the heating of Alfv\'enic slow wind (ASW) by imbalanced…

In magnetized, stratified astrophysical environments such as the Sun's corona and solar wind, Alfv\'enic fluctuations ''reflect'' from background gradients, enabling nonlinear interactions and thus dissipation of their energy into heat.…

Solar and Stellar Astrophysics · Physics 2023-08-22 Romain Meyrand , Jonathan Squire , Alfred Mallet , Benjamin D. G. Chandran

A likely candidate mechanism to heat the solar corona and solar wind is low-frequency "Alfv\'enic" turbulence sourced by magnetic fluctuations near the solar surface. Depending on its properties, such turbulence can heat different species…

Solar and Stellar Astrophysics · Physics 2024-09-17 Jonathan Squire , Romain Meyrand , Matthew W. Kunz

Chapman's (1957) conductive model of the solar corona is characterized by a temperature varying as r**(-2/7) with heliocentric distance r. The density distribution in this non-isothermal hydrostatic model has a minimum value at 123 RS, and…

Solar and Stellar Astrophysics · Physics 2015-06-05 Joseph Lemaire

State-of-the-art MHD calculations reveal acceptable agreement with observational data for the height profile of the temperature $T(h)$ in the transition region of solar corona. Simultaneously, the velocity of the solar wind $U(h)$ has also…

Plasma Physics · Physics 2020-07-29 A. M. Varonov

Parker's initial insights from 1958 provided a key causal link between the heating of the solar corona and the acceleration of the solar wind. However, we still do not know what fraction of the solar wind's mass, momentum, and energy flux…

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

The dynamical response of the solar corona to surface and sub-surface perturbations depends on the chromospheric stratification, and specifically on how efficiently these layers reflect or transmit incoming Alfv\'en waves. While it would be…

Solar and Stellar Astrophysics · Physics 2015-06-12 R. F. Pinto , R. Grappin , M. Velli , A. Verdini

Alfv\'enic waves are considered a key contributor to the energy flux that powers the Sun's corona, with theoretical models demonstrating their potential to explain coronal EUV and X-ray emission and the acceleration of the solar wind.…

Solar and Stellar Astrophysics · Physics 2025-05-14 R. J. Morton , R. Soler

Minor ions in the solar corona are heated to extreme temperatures, far in excess of those of the electrons and protons that comprise the bulk of the plasma. These highly non-thermal distributions make minor ions sensitive probes of the…

Solar and Stellar Astrophysics · Physics 2024-11-21 Michael F. Zhang , Matthew W. Kunz , Jonathan Squire , Kristopher G. Klein

The analysis of energy balance of coronal holes gives that to accelerate the fast solar wind streams the energy flux of the order of 800 erg/cm$^2$ s is needed. Axford and McKenzie suggested that the energy source, necessary to accelerate…

Plasma Physics · Physics 2007-05-23 Andrei Sadovski

We present an updated global model of the solar corona, including the transition region. We simulate the realistic tree-dimensional (3D) magnetic field using the data from the photospheric magnetic field measurements and assume the…

We investigate possibilities of solar coronal heating by acoustic waves generated not at the photosphere but in the corona, aiming at heating in the mid- to low-latitude corona where the low-speed wind is expected to come from. Acoustic…

Astrophysics · Physics 2009-11-07 Takeru Ken Suzuki

The propagation of dissipationless, hydromagnetic, non-WKB, purely toroidal Alfv\'en waves in a realistic background three-fluid solar wind with axial symmetry and differential proton-alpha flow is investigated. The wave equations are…

Astrophysics · Physics 2011-02-11 Bo Li , Xing Li

In the corona, plasma is accelerated to hundreds of kilometers per second, and heated to temperatures hundreds of times hotter than the Sun's surface, before it escapes to form the solar wind. Decades of space-based experiments have shown…

Identifying the heating mechanisms of the solar corona and the driving mechanisms of solar wind are key challenges in understanding solar physics. A full three-dimensional compressible magnetohydrodynamic (MHD) simulation was conducted to…

Solar and Stellar Astrophysics · Physics 2020-11-25 Takuma Matsumoto

Ultraviolet spectroscopy of the extended solar corona is a powerful tool for measuring the properties of protons, electrons, and heavy ions in the accelerating solar wind. The large coronal holes that expand up from the north and south…

Solar and Stellar Astrophysics · Physics 2020-07-28 Steven R. Cranmer