Chromospheric heating by acoustic waves compared to radiative cooling
| Autor: | Michal Švanda, Jan Jurčák, Francesco Berrilli, D. Del Moro, P. Heinzel, Michal Sobotka |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
010504 meteorology & atmospheric sciences
Radiative cooling FOS: Physical sciences Flux Astrophysics plages 01 natural sciences Spectral line Settore FIS/05 - Astronomia e Astrofisica 0103 physical sciences Radiative transfer Astrophysics::Solar and Stellar Astrophysics Sun: oscillations 010303 astronomy & astrophysics Chromosphere Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences Line (formation) Physics Plage Sun: chromosphere Astronomy and Astrophysics Acoustic wave Sun: faculae Sun: faculae plages Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics::Earth and Planetary Astrophysics Settore FIS/06 - Fisica per il Sistema Terra e Il Mezzo Circumterrestre |
| Popis: | Acoustic and magnetoacoustic waves are among the possible candidate mechanisms that heat the upper layers of solar atmosphere. A weak chromospheric plage near a large solar pore NOAA 11005 was observed on October 15, 2008 in the lines Fe I 617.3 nm and Ca II 853.2 nm with the Interferometric Bidimemsional Spectrometer (IBIS) attached to the Dunn Solar Telescope. Analyzing the Ca II observations with spatial and temporal resolutions of 0.4" and 52 s, the energy deposited by acoustic waves is compared with that released by radiative losses. The deposited acoustic flux is estimated from power spectra of Doppler oscillations measured in the Ca II line core. The radiative losses are calculated using a grid of seven 1D hydrostatic semi-empirical model atmospheres. The comparison shows that the spatial correlation of maps of radiative losses and acoustic flux is 72 %. In quiet chromosphere, the contribution of acoustic energy flux to radiative losses is small, only of about 15 %. In active areas with photospheric magnetic field strength between 300 G and 1300 G and inclination of 20-60 degrees, the contribution increases from 23 % (chromospheric network) to 54 % (a plage). However, these values have to be considered as lower limits and it might be possible that the acoustic energy flux is the main contributor to the heating of bright chromospheric network and plages. 9 pages, 10 figures. Accepted for publication in The Astrophysical Journal |
| Databáze: | OpenAIRE |
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