Constraints on acoustic wave energy fluxes and radiative losses in the solar chromosphere from non-LTE inversions

We investigate the energy balance in the chromosphere by comparing deposited acoustic flux and radiative losses under quiet and active solar conditions using non–local thermodynamic equilibrium inversions with the Stockholm Inversion Code. To achieve this, we utilize spectroscopic observations from the Interferometric BIdimensional Spectrometer in the Na i 5896 Å and Ca ii 8542 Å lines and from the Interface Region Imaging Spectrograph in the Mg ii h and k lines to self-consistently derive spatially resolved velocity power spectra and cooling rates across different heights in the atmosphere.

Additionally, we use snapshots of a three-dimensional radiative magnetohydrodynamics simulation to investigate the systematic effects of the inversion approach, particularly the effect of attenuation on the velocity power spectra and the determination of the cooling rates. The results indicate that inversions potentially underestimate acoustic fluxes at all chromospheric heights while slightly overestimating the radiative losses when fitting these spectral lines.