Using the COSMIC GPS occultation data of ionosphere density, we examine the longitudinal variations. We use a two dimensional spectral analysis method to extract variations in zonal direction in terms of zonal wavenumbers from -5 to 5 and oscillations of time period from a few hours to a few days. We will focus on ionosphere oscillations with appearances of tidal modes and their season variations. At the same time, mesospheric and lower thermospheric (MLT) winds observed by the TIMED satellite will be analyzed to extract tidal modes in the MLT region. The goal is to find any links between the MLT tides and F region ionosphere longitudinal variations.