Coupling of solar p modes: quasi-degenerate perturbation theory
M. Roth and
Received 21 June 1999 / Accepted 21 September 1999
The interaction of a large-scale stationary poloidal velocity field (as a simple model for possibly existing giant cells) with solar p-mode oscillations is described by quasi-degenerate perturbation theory, as proposed by Lavely & Ritzwoller (1992). For oscillations of low degree () and sectoral velocity fields we obtain numerical solutions of the eigenvalue problem, and derive an approximate formula for the ensuing frequency splitting. The coupling of the oscillation modes leads to asymmetric frequency multiplets, with splittings of up to nHz for a velocity with amplitude m s-1. The splitting scales with , with the oscillation frequency itself, and with the inverse difference of the squared frequencies of the coupling partners. Possible observable effects are briefly discussed.
Key words: convection Sun: interior Sun: oscillations
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© European Southern Observatory (ESO) 1999
Online publication: November 16, 1999