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Related papers: Effects of non-WKB Alfven waves on a multicomponen…

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Plasma kinetic waves and alpha-proton differential flow are two important subjects on the topic of evolution of the solar wind. Based on the Wind data during 2005-2015, this paper reports that the occurrence of electromagnetic cyclotron…

Space Physics · Physics 2019-10-16 G. Q. Zhao , H. Li , H. Q. Feng , D. J. Wu , H. B. Li , A. Zhao

We use magnetic helicity to characterise solar wind fluctuations at proton-kinetic scales from Wind observations. For the first time, we separate the contributions to helicity from fluctuations propagating at angles quasi-parallel and…

One view of the solar-wind turbulence is that the observed highly anisotropic fluctuations at spatial scales near the proton inertial length $d_p$ may be considered as Kinetic Alfv\'en waves (KAWs). In the present paper, we show how…

Solar and Stellar Astrophysics · Physics 2015-12-09 C. L. Vasconez , F. Pucci , F. Valentini , S. Servidio , W. H. Matthaeus , F. Malara

We show that the scaling of structure functions of magnetic and velocity fields in a mostly highly Alfv\'{e}nic fast solar wind stream depends strongly on the joint distribution of the dimensionless measures of cross helicity and residual…

Fluctuations of solar wind magnetic field and plasma parameters exhibit a typical turbulence power spectrum with a spectral index ranging between $\sim -5/3$ and $\sim -3/2$. In particular, at $1$ AU, the magnetic field spectrum, observed…

Space Physics · Physics 2019-07-10 R. Bruno , D. Telloni , L. Sorriso-Valvo , R. Marino , R. De Marco , R. DAmicis

In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic (MHD) to sub-ion scales using in-situ measurements of the Wind…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sonny Lion , Olga Alexandrova , Arnaud Zaslavsky

The solar corona is a hot, dynamic, and highly magnetized plasma environment whose source of energy is not yet well understood. One leading contender for that energy source is the dissipation of magnetohydrodynamic (MHD) waves or turbulent…

Solar and Stellar Astrophysics · Physics 2018-08-01 Steven R. Cranmer

We present three-dimensional magnetic power spectra in wavevector space to investigate anisotropy and scalings of sub-Alfv\'enic solar wind turbulence at magnetohydrodynamic (MHD) scale using the Magnetospheric Multiscale spacecraft. The…

Solar and Stellar Astrophysics · Physics 2022-11-29 S. Q. Zhao , Huirong Yan , Terry Z. Liu , Mingzhe Liu , Huizi Wang

Alfven waves propagating in a vertically stratified plasma, such as those travelling from the solar photosphere to the corona, are partially reflected due to the gradient in the Alfven speed. Wave reflection naturally results in the…

Solar and Stellar Astrophysics · Physics 2025-04-15 Roberto Soler

Using advanced numerical magneto-hydrodynamic simulations of the magnetised solar photosphere, including non-grey radiative transport and a non-ideal equation of state, we analyse plasma motions in photospheric magnetic vortices. We…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Shelyag , P. S. Cally , A. Reid , M. Mathioudakis

Protons and alpha particles in the fast solar wind are only weakly collisional and exhibit a number of non-equilibrium features, including relative drifts between particle species. Two non-collisional mechanisms have been proposed for…

In a magnetised plasma on scales well above ion kinetic scales, any constant-magnitude magnetic field, accompanied by parallel Alfv\'enic flows, forms a nonlinear solution in an isobaric, constant-density background. These structures, which…

Solar and Stellar Astrophysics · Physics 2022-09-01 Jonathan Squire , Alfred Mallet

This Letter investigates the spectral characteristics of the interplanetary magnetic field fluctuations at proton scales during several time intervals chosen along the speed profile of a fast stream. The character of the fluctuations within…

Solar and Stellar Astrophysics · Physics 2015-09-30 R. Bruno , D. Telloni

Close to Earth the solar wind is usually super-Alfv\'enic, i.e. the speed of the solar wind is much larger than the Alfv\'en speed. However, in the lower coronal regions, the solar wind is mostly sub-Alfv\'enic. With the Parker Solar Probe…

The nonlinear evolution of Alfv\'en waves in the solar corona leads to the generation of Alfv\'enic turbulence. This description of the Alfv\'en waves involves parametric instabilities where the parent wave decays into slow mode waves…

Measurements of small-scale turbulent fluctuations in the solar wind find a non-zero right-handed magnetic helicity. This has been interpreted as evidence for ion cyclotron damping. However, theoretical and empirical evidence suggests that…

Earth and Planetary Astrophysics · Physics 2015-05-14 Gregory G. Howes , Eliot Quataert

We present a measurement of the energy carried and dissipated by Alfv\'en waves in a polar coronal hole. Alfv\'en waves have been proposed as the energy source that heats the corona and drives the solar wind. Previous work has shown that…

Solar and Stellar Astrophysics · Physics 2015-06-15 Michael Hahn , Daniel W. Savin

We present three-dimensional, hybrid-kinetic numerical simulations of driven Alfv\'{e}n-wave turbulence of relevance to the collisionless near-Earth solar wind. Special attention is paid to the spectral transition that occurs near the…

High Energy Astrophysical Phenomena · Physics 2019-07-10 Lev Arzamasskiy , Matthew W. Kunz , Benjamin D. G. Chandran , Eliot Quataert

Observations of the solar corona and the solar wind discover that the solar wind is unsteady and originates from the impulsive events near the surface of the Sun's atmosphere. How solar coronal activities affect the properties of the solar…

Solar and Stellar Astrophysics · Physics 2018-11-14 H. Che

M dwarf's atmosphere and wind is expected to be highly magnetized. The nonlinear propagation of Alfv\'en wave could play a key role in both heating the stellar atmosphere and driving the stellar wind. Along this Alfv\'en wave scenario, we…

Solar and Stellar Astrophysics · Physics 2021-01-20 Takahito Sakaue , Kazunari Shibata