Solar p and g modes in a model with a convection layer above a sub-adiabatic interior

We study high-order acoustic modes which reside in the outer layers of the solar interior. Magnetic field effects are not taken into account in this p aper as we wish first to filter out how the modal frequencies depend on phy sical characteristics of a particular model structure of the Sun. In partic ular, we are interested in how the modal frequencies of solar global oscill ations depend on the thickness of the convection layer and on the temperatu re gradient of the solar interior below. The model we use consists of three planar layers: an isothermal atmosphere, while the convection layer and th e interior have temperature gradients that are adiabatic and sub-adiabatic, respectively. The presence of a convection layer with a finite thickness b rings in additional modes while the variations in temperature gradient of t he interior cause shifts in eigenfrequencies that are more pronounced for t he p modes than for the g modes. These shifts can easily be of the order of several hundreds of mu Hz, which is much larger than the observational acc uracy.