The height dependence of quiet-sun photospheric temperature fluctuations in observations and simulations

Abstract

We derive rms temperature fluctuations as a function of height throughout the solar photosphere for the non-magnetic photosphere and a small area of enhanced magnetic activity, through semi-empirical inversion based on response functions of a 15-minute time sequence of 118″-long slit spectrograms taken at disk center. While the observed low photosphere shows small temperature fluctuations (about ≈ 50 K), the sub-photospheric layers and the upper photosphere show larger fluctuations, with similar gradients as in 3-D radiation-hydrodynamics simulations. However, the observed rms temperature fluctuations are lower than in the simulations at all depths, which we attribute to smearing by atmospheric seeing.