# Energy Input Flux in the Global Quiet-Sun Corona

## TL;DR

This paper introduces a new technique combining EUV tomography and magnetic field models to estimate the energy flux at the quiet-Sun coronal base, providing constraints for coronal heating theories.

## Contribution

It presents the first global-scale constraints on energy input flux at the quiet-Sun coronal base using a novel combined tomography and magnetic modeling approach.

## Key findings

- Energy input flux ranges from 0.5 to 2.0 x 10^5 erg/sec/cm^2.
- A significant portion of the energy may be supplied by Alfvén waves.
- Technique applied to data from STEREO/EUVI and SDO/AIA for different solar activity levels.

## Abstract

We present first results of a novel technique that provides, for the first time, constraints on the energy input flux at the coronal base ($r\sim\,1.025\,{\rm R}_\odot$) of the quiet-Sun at a global scale. By combining differential emission measure tomography (DEMT) of EUV images, with global models of the coronal magnetic field, we estimate the energy input flux at the coronal base that is required to maintain thermodynamically stable structures. The technique is described in detail and first applied to data provided by the Extreme Ultraviolet Imager (EUVI) instrument, on board the Solar TErrestrial RElations Observatory (STEREO) mission, and the Atmospheric Imaging Assembly (AIA) instrument, on board the Solar Dynamics Observatory (SDO) mission, for two solar rotations with different levels of activity. Our analysis indicates that the typical energy input flux at the coronal base of magnetic loops in the quiet-Sun is in the range $\sim\,0.5-2.0\times 10^5\,{\rm (erg\,sec^{-1}\,{\rm cm}^{-2})}$, depending on the structure size and level of activity. A large fraction of this energy input, or even its totality, could be accounted for by Alfv\'en waves, as shown by recent independent observational estimates derived from determinations of the non-thermal broadening of spectral lines in the coronal base of quiet-Sun regions. This new tomography product will be useful for validation of coronal heating models in magnetohydrodinamic simulations of the global corona.