Radiation loss and mechanical heating in the low solar chromosphere

Abstract

We discuss Ulmschneider's claim to have established that the short-period acoustic wave energy input is the only one able to balance the chromospheric radiation loss. We first review the range of uncertainty in empirical and radiative equilibrium models, on which estimates of the excess radiation coming from mechanical heating rest. We then show that Ulmschneider's estimate of this excess radiation from such models uses an over-simplified computational method. The resultant of uncertainty in models and in computational methods suggests that Ulmschneider's results on excess radiation from heating in the low chromosphere is subject to overestimation by an order of magnitude.