Ring diagram analysis of velocity fields within the solar convection zone

Abstract

Ring diagram analysis of solar oscillation power spectra obtained from GONG and MDI data is performed to study the velocity fields within the solar convection zone. The three dimensional power spectra are fitted to a model with Lorentzian profile in frequency and includes the advection of the wave front by horizontal flows. We obtain the two horizontal components of flows as a function of the horizontal wave number and radial order of the oscillation modes. This information is then inverted using the OLA and RLS techniques to infer the variation in flow velocity with depth.