Constraining Poynting flux in the quiet Sun photosphere using observations and simulations

The flux of magnetic energy, or Poynting flux, is usually thought to be responsible for the heating of the solar chromosphere and corona. Quantifying it is important in order to understand the energy budget at different heights in the solar atmosphere, but doing so requires computing several intermediate quantities, particularly full magnetic and velocity vectors. This requires, among other problems, to address the issue of 180º magnetic field azimuthal ambiguity. Poynting flux has been computed for active regions and plage, but the quiet Sun (QS) is a difficult and insufficiently studied target due to inherently weak, compact, and transient magnetic field concentrations. In this talk, we will discuss our efforts to compute Poynting fluxes using Sunrise/IMaX magnetograms of QS. We find that the magnetic energy flux from the photosphere is insufficient to explain chromospheric and coronal heating. However, using MURaM radiative MHD simulations, we find strong biases that likely lower the observable flux. Due to the same biases, we find that the choice of azimuth disambiguation method does not significantly affect Poynting flux values. Finally, we use MURaM simulations to test the sensitivity of our methods to various observational constraints. With this we hope to develop observing strategies that would minimize biases and allow us to recover Poynting flux accurately.