Influence of wave noise on frequencies and amplitudes of the solar -modes

¹ Department of Complex Physical Systems, Institute of Physics, UMCS, ul. Radziszewskiego 10, 20-031 Lublin, Poland
² Institute of Atomic and Molecular Physics, National Research Council, Via Moruzzi 1, 56124 Pisa, Italy
³ Institute of Applied Physics, 46 Ul'anova Street 603600, Nizhny Novgorod, Russia

Corresponding author: K. Murawski, kmurawsk@tytan.umcs.lublin.pl

Received: 16 November 2001
Accepted: 12 March 2002

Abstract

The influence of space- and time-dependent random mass density field, associated with granules, on frequencies and amplitudes of the solar p-modes is examined in the limit of weak random fields and small amplitude oscillations. The p-modes are approximated by the sound waves which propagate in the gravity-free medium. Using a perturbative method, we derive a dispersion relation which is solved for the case of wave noise for which the spectrum , where δ is the Dirac's delta-function and c_r is the random phase speed. We find that at a resonance occurs at which the cyclic frequency ω tends to infinity. For values of c_r which are close to the resonance point, the frequency shift may be both negative or positive and the imaginary part of the frequency attains the negative (positive) sign for ().