Astron. Astrophys. 359, 759-765 (2000)

5. Summary

The need for improved theoretical models of the influence of a turbulent flow on the solar acoustic waves is emphasized by recent results from helioseismology, which have provided information on the dynamics of the solar interior.

In this paper we have developed a theoretical model of the effect of random flow on the spectrum of solar acoustic oscillations. A random flow can decrease the frequencies of acoustic waves since these waves take longer to travel a given distance due to the scattering from random field (Howe 1971). However, the analytical results have also revealed that the random flow can both increase and decrease the frequencies, depending on the parameters of the flow and the spherical harmonic degree l.

The numerical simulations for a linear set of wave equations have revealed damping and amplification of the sound waves as well as frequency decrease by the random flow. The results of these simulations are in an agreement with the analytical findings for low strength of the random flow, .

© European Southern Observatory (ESO) 2000

Online publication: July 7, 2000
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