Results 21 to 30 of about 3,072 (224)

Rotational Characteristics of the Solar Transition Region Using SDO/AIA 304 Å Images

open access: yesThe Astrophysical Journal, 2023
To date, the rotational characteristics of the solar transition region remain unclear. In this work, by applying the flux modulation method to the images derived from the Solar Dynamics Observatory/Atmospheric Imaging Assembly between 2011 and 2022 at ...
Qian-Rui Wu   +6 more
doaj   +1 more source

Ionisation in the Solar Chromosphere [PDF]

open access: yesNature, 1920
IT is well known that the spectrum of the upper layers of the solar chromosphere is chiefly composed of those lines which are relatively more strengthened in the spark than in the arc, and which Sir Norman Lockyer originally styled enhanced lines. The best-known examples are the calcium H and K and the strontium pair (4216, 4077).
openaire   +1 more source

MHD turbulence and heating of the open field-line solar corona [PDF]

open access: yes, 2003
This paper discusses the possibility that heating of the solar corona in open field-line regions emanating from coronal holes is due to a nonlinear cascade, driven by low-frequency or quasi-static magnetohydrodynamic fluctuations.
Dmitruk, Pablo   +13 more
core   +1 more source

Propagating and Stationary Bright Knots in the Quiet Sun

open access: yesThe Astrophysical Journal Letters, 2022
The question of what heats the solar chromosphere and corona remains one of the most important puzzles in solar physics and astrophysics. Up to now, two mechanisms are considered to work in heating the chromosphere and corona: magnetic reconnection and ...
Jun Zhang   +9 more
doaj   +1 more source

Investigating Alfvénic wave propagation in coronal open-field regions [PDF]

open access: yes, 2015
The physical mechanisms behind accelerating solar and stellar winds are a long-standing astrophysical mystery, although recent breakthroughs have come from models invoking the turbulent dissipation of Alfvén waves.
Morton, Richard   +2 more
core   +1 more source

The influence of the magnetic field on running penumbral waves in the solar chromosphere [PDF]

open access: yes, 2013
We use images of high spatial and temporal resolution, obtained using both ground- and space-based instrumentation, to investigate the role magnetic field inclination angles play in the propagation characteristics of running penumbral waves in the solar ...
Jess, D.B.; id_orcid   +12 more
core   +1 more source

Chromospheric Heating from Local Magnetic Growth and Ambipolar Diffusion under Nonequilibrium Conditions

open access: yesThe Astrophysical Journal Letters, 2023
The heating of the chromosphere in internetwork regions remains one of the foremost open questions in solar physics. In the present study, we tackle this old problem by using a very-high-spatial-resolution simulation of quiet-Sun conditions performed ...
Juan Martínez-Sykora   +5 more
doaj   +1 more source

Photospheric magnetic vortex structures [PDF]

open access: yes, 2011
Using direct numerical magneto-hydrodynamic (MHD) simulations, we demonstrate the evidence of two physically different types of vortex motions in the solar photosphere.
Shelyag, S.   +14 more
core   +1 more source

Magnetoacoustic Heating of the Solar Chromosphere

open access: yesThe Astrophysical Journal, 1991
Long-period acoustic waves generated in the solar convection zone can propagate radially outward through the overlying atmosphere and get resonantly absorbed in the magnetic arches of the low-lying chromospheric canopy. The resulting Poynting and acoustic flux that enters the magnetic canopy in the network regions is demonstrated to be adequate to ...
Joseph M. Davila, S. M. Chitre
openaire   +1 more source

Collisional dissipation of Alfvén waves in a partially ionised solar chromosphere [PDF]

open access: yes, 2005
Certain regions of the solar atmosphere are at sufficiently low temperatures to be only partially ionised. The lower chromosphere contains neutral atoms, the existence of which greatly increases the efficiency of the damping of waves due to collisional ...
J. E. Leake   +5 more
core   +1 more source

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