Approximations for radiative cooling and heating in the solar chromosphere
By M. Carlsson, J. Leenaarts. 2012
160 citations recorded by the source corpus.
Context. The radiative energy balance in the solar chromosphere is dominated by strong spectral lines that are formed out of LTE. It is computationally prohibitive to solve the full equations of radiative transfer and statistical equilibrium in 3D time dependent MHD simulations. Aims. We look for simple recipes to compute the radiative energy balance in the dominant lines under solar chromospheric conditions. Methods. We use detailed calculations in time-dependent and 2D MHD snapshots to derive empirical formulae for the radiative cooling and heating. Results. The radiative cooling in neutral hydrogen lines and the Lyman continuum, the H and K and intrared triplet lines of singly ionized calcium and the h and k lines of singly ionized magnesium can be written as a product of an optically thin emission (dependent on temperature), an escape probability (dependent on column mass) and an ionization fraction (dependent on temperature). In the cool pockets of the chromosphere the same transitions contribute to the heating of the gas and similar formulae can be derived for these processes. We finally derive a simple recipe for the radiative heating of the chromosphere from incoming coronal radiation. We compare our recipes with the detailed results and comment on the accuracy and applicability of the recipes.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/267668c949d35b1b1d205a1dab499e0f57a6b386
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In Astronomy and Astrophysics
Citations in the corpus
- A publicly available simulation of an enhanced network region of the Sun (2015, methodology): “Chromospheric radiative losses are calculated in nonLTE using simplified recipes (Carlsson & Leenaarts 2012) based on detailed 1D full non-LTE radiative transfer simulations using the RADYN code (Carlsson & Stein 1992, 1995, 1997, 2002).”
- THE FORMATION OF IRIS DIAGNOSTICS. II. THE FORMATION OF THE Mg ii h&k LINES IN THE SOLAR ATMOSPHERE (2013, background): “…(Nordlund 1982; Skartlien 2000; Hayek et al. 2010) parametrized radiative losses in the upper chromosphere, transition region and corona (Carlsson & Leenaarts 2012), thermal conduction along magnetic field lines (Gudiksen et al. 2011) and an equation of state that includes the effects…”
- Multiwavelength Studies of MHD Waves in the Solar Chromosphere (2015, background): “However, as time progressed, it became clear that even 2D non-LTE models (e.g., van Noort et al. 2002; Carlsson and Leenaarts 2012) of the solar atmosphere were not entirely representative of the observed chromospheric structures (de la Cruz Rodríguez et al. 2012; Leenaarts et al. 2012).”