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The solar atmosphere is known to contain many different types of wavelike oscillation. Waves and other fluctuations (e.g., turbulent eddies) are believed to be responsible for at least some of the energy transport and dissipation that heats…

Solar and Stellar Astrophysics · Physics 2023-08-09 Steven R. Cranmer , Momchil E. Molnar

Here we investigate the contribution of surface Alfven wave damping to the heating of the solar wind in minima conditions. These waves are present in regions of strong inhomogeneities in density or magnetic field (e. g., the border between…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. M. Evans , M. Opher , V. Jatenco-Pereira , T. I. Gombosi

In the quest to solve the long-standing coronal heating problem, it has been suggested half a century ago that coronal loops could be heated by waves. Despite the accumulating observational evidence of the possible importance of coronal…

Solar and Stellar Astrophysics · Physics 2021-02-26 Mijie Shi , Tom Van Doorsselaere , Mingzhe Guo , Konstantinos Karampelas , Bo Li , Patrick Antolin

Transverse magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere and may be responsible for generating the Sun's million-degree outer atmosphere. However, direct evidence of the dissipation process and heating from these…

Solar and Stellar Astrophysics · Physics 2015-08-19 Patrick Antolin , Takenori J. Okamoto , Bart De Pontieu , Han Uitenbroek , Tom Van Doorsselaere , Takaaki Yokoyama

We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Measurements made by UVCS/SOHO have revived interest in the…

Astrophysics · Physics 2009-11-07 S. R. Cranmer , A. A. van Ballegooijen

We have measured the widths of spectral lines from a polar coronal hole using the Extreme Ultraviolet Imaging Spectrometer onboard Hinode. Polar coronal holes are regions of open magnetic field and the source of the fast solar wind. We find…

Solar and Stellar Astrophysics · Physics 2015-06-04 Michael Hahn , Enrico Landi , Daniel Wolf Savin

We analyze the evolution of shock waves in high-resolution 3D radiative MHD simulations of the quiet Sun and their synthetic emission characteristics. The simulations model the dynamics of a 12.8x12.8x15.2 Mm quiet-Sun region (including a…

Solar and Stellar Astrophysics · Physics 2021-03-16 Viacheslav M. Sadykov , Irina N. Kitiashvili , Alexander G. Kosovichev , Alan A. Wray

Spectral observations of the solar transition region (TR) and corona show broadening of spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant (5-30 km/s) and…

Solar and Stellar Astrophysics · Physics 2017-10-19 Bart De Pontieu , Scott McIntosh , Juan Martinez-Sykora , Hardi Peter , Tiago Pereira

We have measured the energy and dissipation of Alfvenic waves in the quiet Sun. A magnetic field was used to infer the location and orientation of the magnetic field lines along which the waves are expected to travel. The waves were…

Solar and Stellar Astrophysics · Physics 2015-06-22 Michael Hahn , Daniel Wolf Savin

Transverse MHD waves permeate the solar atmosphere and are a candidate for coronal heating. However, the origin of these waves is still unclear. In this work, we analyse coordinated observations from \textit{Hinode}/SOT and \textit{IRIS} of…

Solar and Stellar Astrophysics · Physics 2018-07-25 Patrick Antolin , Paolo Pagano , Ineke De Moortel , Valery M. Nakariakov

There is observational evidence of the presence of small-amplitude transverse magnetohydrodynamic (MHD) waves with a wide range of frequencies in the threads of solar prominences. It is believed that the waves are driven at the photosphere…

Solar and Stellar Astrophysics · Physics 2021-06-09 Llorenc Melis , Roberto Soler , Jose Luis Ballester

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

The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can…

Solar and Stellar Astrophysics · Physics 2015-03-12 D. B. Jess , R. J. Morton , G. Verth , V. Fedun , S. D. T. Grant , I. Giagkiozis

Acoustic waves are one of the primary suspects besides magnetic fields for the chromospheric heating process to temperatures above radiative equilibrium (RE). We derived the mechanical wave energy as seen in line-core velocities to obtain a…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Beck , E. Khomenko , R. Rezaei , M. Collados

The energy of the thermal flare plasma and the kinetic energy of the non-thermal electrons in 14 hard X-ray peaks from 9 medium-sized solar flares have been determined from RHESSI observations. The emissions have been carefully separated in…

Astrophysics · Physics 2007-05-23 Pascal Saint-Hilaire , Arnold O. Benz

The investigation of plasma motions in the solar chromosphere is crucial for understanding the transport of mechanical energy from the interior of the Sun to the outer atmosphere and into interplanetary space. We report the finding of…

Solar and Stellar Astrophysics · Physics 2024-07-17 Jongchul Chae , Michiel van Noort , Maria S. Madjarska , Kyeore Lee , Juhyung Kang , Kyuhyoun Cho

Recent observations with the Atmospheric Imaging Assembly (AIA) instrument on the SDO spacecraft have revealed the existence of decayless coronal kink oscillations. These transverse oscillations are not connected to any external phenomena…

Solar and Stellar Astrophysics · Physics 2019-06-06 K. Karampelas , T. Van Doorsselaere , D. J. Pascoe , M. Guo , P. Antolin

Magnetohydrodynamic (MHD) waves have been considered as energy sources for heating the solar chromosphere and the corona. Although MHD waves have been observed in the solar atmosphere, there are a lack of quantitative estimates on the…

Solar and Stellar Astrophysics · Physics 2016-11-01 Ryuichi Kanoh , Toshifumi Shimizu , Shinsuke Imada

Alfv\'{e}n waves are believed to play an important role in the heating and acceleration of the fast solar wind emanating from coronal holes. Nonlinear interactions between the dominant ${\bf z}_{+}$ waves and minority ${\bf z}_{-}$ waves…

Solar and Stellar Astrophysics · Physics 2017-01-25 Adriaan A. van Ballegooijen , Mahboubeh Asgari-Targhi

We investigate the interaction of magnetohydrodynamic waves with plasma density inhomogeneities. Our numerical study of the full MHD equations shows that: (A) Plasma density inhomogeneities are a source of non-linear generation of…

Astrophysics · Physics 2007-05-23 D. Tsiklauri , V. M. Nakariakov , T. D. Arber