Results 31 to 40 of about 1,455,996 (195)
Diagnostics of active and eruptive prominences through hydrogen and helium lines modelling [PDF]
, 2008 In this study we show how hydrogen and helium lines modelling can be used to make a diagnostic of active and eruptive prominences. One motivation for this work is to identify the physical conditions during prominence activation and eruption. Hydrogen and
Labrosse, N. +2 more
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The Heating of the Quiet Solar Chromosphere [PDF]
Symposium - International Astronomical Union, 1990 The quiet solar chromosphere shows three distinct regions. Ordered according to the strength of the emission from the low and middle chromosphere they are (1) the magnetic elements on the boundary of supergranulation cells, (2) the bright points in the cell interior, and (3) the truly quiet chromosphere, also in the cell interior. The magnetic elements
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Chromospheric seismology above sunspot umbrae [PDF]
, 2015 Context: The acoustic resonator is an important model for explaining the three-minute oscillations in the chromosphere above sunspot umbrae. The steep temperature gradients at the photosphere and transition region provide the cavity for the acoustic ...
G. J. J. Botha +5 more
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ON THE SPATIAL SCALES OF WAVE HEATING IN THE SOLAR CHROMOSPHERE
The Astrophysical Journal, 2015 Dissipation of magnetohydrodynamic (MHD) wave energy has been proposed as a viable heating mechanism in the solar chromospheric plasma. Here, we use a simplified one-dimensional model of the chromosphere to theoretically investigate the physical processes and the spatial scales that are required for the efficient dissipation of Alfvén waves and slow ...
Roberto Soler +2 more
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HEATING OF THE SOLAR CHROMOSPHERE AND CORONA BY ALFVÉN WAVE TURBULENCE [PDF]
The Astrophysical Journal, 2011 A three-dimensional MHD model for the propagation and dissipation of Alfven waves in a coronal loop is developed. The model includes the lower atmospheres at the two ends of the loop. The waves originate on small spatial scales (less than 100 km) inside the kilogauss flux elements in the photosphere.
van Ballegooijen, A. A. +3 more
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Astronomy & AstrophysicsContext. The solar chromosphere is a dynamic and crucial interface between the solar interior and its interplanetary environment, regulating how energy is locally deposited into heat and transported into the upper atmospheric layers.
Noraz Q., Carlsson M., Aulanier G.
doaj +3 more sources
Model solar chromosphere with prescribed heating
The Astrophysical Journal, 1989 Computed model solar chromospheres for prescribed departures from radiative equilibrium are specified in terms of the local mechanical (nonradiative) heat input. The computations are fully non-LTE and include millions of spectral lines. From the variety of models considered, the requirements on the heat input for a positive temperature gradient, dT/dh,
Lawrence S. Anderson, R. Grant Athay
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Heating of the solar chromosphere through current dissipation
Astronomy & Astrophysics, 2022 Context.The solar chromosphere is heated to temperatures higher than predicted by radiative equilibrium. This excess heating is greater in active regions where the magnetic field is stronger.Aims.We aim to investigate the magnetic topology associated with an area of enhanced millimeter (mm) brightness temperatures in a solar active region mapped by the
J. M. da Silva Santos +7 more
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Solar Atmospheric Heating Due to Small-scale Events in an Emerging Flux Region
The Astrophysical Journal, 2023 We investigate the thermal, kinematic, and magnetic structure of small-scale heating events in an emerging flux region (EFR). We use high-resolution multiline observations (including Ca ii 8542 Å, Ca ii K, and the Fe i 6301 Å line pair) of an EFR located
Rahul Yadav +4 more
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Heating and dynamics of the quiet solar chromosphere [PDF]
Proceedings of the International Astronomical Union, 2007 AbstractThe quiet solar chromosphere in regions with negligible magnetic field is believed to be heated by acoustic waves. But their energy flux, measured in the upper photosphere with the Transition Region And Coronal Explorer (TRACE), has been found to be insufficient to account for the radiative emission from the chromosphere. Wedemeyer-Böhm et al. (
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