The main subject of this work is to investigate the ultra-fast Kelvin wave effects over the Brazilian equatorial ionosphere. The ultra-fast Kelvin wave is an equatorial wave propagating eastward with a period of 3-4-days, and because of its long vertical wavelength (~ 60 km) and low susceptibility for dissipation, it has been used to investigate the mechanisms related to the coupling between the lower and upper atmosphere. For this purpose, the meteor wind data from São João do Cariri (7.4 S, 36.5 W) and ionospheric data from Fortaleza (3.9 S, 38.4 W) in the year 2005 were used. Temporal variations of the zonal and meridional winds, and h’F and foF2 were submitted to a wavelet analysis in order to indentify the oscillations present in the series. The study was conducted for the time intervals when the ultra-fast Kelvin waves are present in both the mesospheric and ionospheric parameters. For each of these intervals, the amplitude and phase of the propagating wave were calculated from the wind data. The effect of the ultra-fast Kelvin waves on the ionospheric parameters is tested using an ionospheric model that solves the coupled electrodynamics of the equatorial ionosphere and calculates the electrostatic potential for the E region and the F region vertical and horizontal plasma drifts. Some relevant results obtained from the comparison between observation and model results will be presented and discussed.