The pulsation of the solar surface is caused by acoustic waves traveling in the solar interior. These f and p oscillation modes are not bounced back completely at the surface, but partially penetrate into the atmosphere. Here the atmospheric effects are investigated analytically on global oscillations in one-dimensional magnetohydrodynamic (MHD) models. We focus on the frequency spectrum of the f mode, hence an incompressible medium is considered. The global oscillation modes can be coupled resonantly to local atmospheric MHD modes (such as Alfvén and degenerated slow waves) causing frequency shifts and line broadening. An analytical approach is implemented for a first insight.