Chromospheric Heating by Acoustic Waves Compared to Radiative Cooling. II. Revised Grid of Models
Abstract
Acoustic and magnetoacoustic waves are considered to be possible agents of chromospheric heating. We present a comparison of deposited acoustic energy flux with total integrated radiative losses in the middle chromosphere of the quiet Sun and a weak plage. The comparison is based on a consistent set of high-resolution observations acquired by the Interferometric Bidimensional Spectrometer instrument in the Ca II 854.2 nm line. The deposited acoustic-flux energy is derived from Doppler velocities observed in the line core and a set of 1737 non-local thermodynamic equilibrium 1D hydrostatic semi-empirical models, which also provide the radiative losses. The models are obtained by scaling the temperature and column mass of five initial models by Vernazza et al. (1981; VAL) B-F to get the best fit of synthetic to observed profiles. We find that the deposited acoustic-flux energy in the quiet-Sun chromosphere balances 30%-50% of the energy released by radiation. In the plage, it contributes by 50%-60% in locations with vertical magnetic field and 70%-90% in regions where the magnetic field is inclined more than 50° to the solar surface normal.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2020
- DOI:
- arXiv:
- arXiv:2001.03413
- Bibcode:
- 2020ApJ...890...22A
- Keywords:
-
- Solar chromospheric heating;
- Plages;
- Solar chromosphere;
- 1987;
- 1240;
- 1479;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 9 pages, 8 figures