Acoustic waves in the solar atmosphere. I - The hydrodynamic code

Abstract

This paper studies large-amplitude radiatively damped acoustic waves in the solar atmosphere. A modified method of characteristics is described for the solution of the time-dependent hydrodynamic equations in a gravitational atmosphere. A procedure for the detection of shocks is outlined. Several tests of the accuracy of the method are described. The evolution of the wave and the height of shock formation are computed for several values of the period and the initial acoustic flux in isothermal atmospheres with temperatures of 4000 and 5000 K as well as in a model solar atmosphere.