We describe a global parametric model for the observed power spectra of solar oscillations of intermediate and low degree. A physically motivated parameterization is used as a substitute for a direct description of mode excitation and damping as thes
e mechanisms remain poorly understood. The model is targeted at the accurate fitting of power spectra coming from Doppler velocity measurements and uses an adaptive response function that accounts for both the vertical and horizontal components of the velocity field on the solar surface and for possible instrumental and observational distortions. The model is continuous in frequency, can easily be adapted to intensity measurements and extends naturally to the analysis of high-frequency pseudo modes (interference peaks at frequencies above the atmospheric acoustic cutoff).
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.
