On the Role of Acoustic-gravity Waves in the Energetics of the Solar Atmosphere

TL;DR

This study confirms that acoustic-gravity waves are the main energy carriers in the quiet solar atmosphere, transporting more energy than high-frequency acoustic waves, which impacts our understanding of solar chromosphere heating.

Contribution

The paper extends previous work by using coordinated observations from multiple instruments to quantify the energy flux of gravity waves in the solar atmosphere.

Findings

Gravity waves dominate energy transport in the quiet middle/upper photosphere.

Gravity waves carry more mechanical energy than high-frequency acoustic waves.

The acoustic flux measured exceeds previous estimates, suggesting a reevaluation of wave contributions.

Abstract

In a recent paper (Straus et al. 2008) we determined the energy flux of internal gravity waves in the lower solar atmosphere using a combination of 3D numerical simulations and observations obtained with the IBIS instrument operated at the Dunn Solar Telescope and the Michelson Doppler Imager (MDI) on SOHO. In this paper we extend these studies using coordinated observations from SOT/NFI and SOT/SP on Hinode and MDI. The new measurements confirm that gravity waves are the dominant phenomenon in the quiet middle/upper photosphere and that they transport more mechanical energy than the high-frequency (> 5mHz) acoustic waves, even though we find an acoustic flux 3-5 times larger than the upper limit estimate of Fossum & Carlsson (2005). It therefore appears justified to reconsider the significance of (non-M)HD waves for the energy balance of the solar chromosphere.