Some aspects of the interpretation of frequency splitting data

Abstract

Many dynamo and dynamical models of the convection Zone require that the angular velocity be approximately constant on cylinders concentric about the rotation axis ('constant-on-cylinders'). However, inferences from the earliest helioseismology data that the internal angular velocity of the Sun is invariant across the convection zone, i.e. within the convection zone it is constant on radial cones with vertices at the center ('constant-on-cones'), have caused some concern to theoreticians. This has led to a re-examination of these inferences and Gough and his colleagues have recently claimed that the currently available data are not inconsistent with some models for which the angular velocity is constant on cylinders within the Sun's convection zone outside the tangent cylinder. Thus it would appear that, on the basis of current frequency splitting data, we can eliminate neither the 'constant-on-cylinders' nor the 'constant-on-cones' classes of models. In this paper, this problem is discussed and an alternative approach is proposed in which a forward method is used to 'characterize' the essential properties of a particular data set.