Signatures of ultra fast Kelvin waves in the equatorial middle atmosphere and ionosphere

In the equatorial atmosphere, oscillations with periods of 3 to 4 days have been observed in the meteor radar zonal wind at Cariri ( 7.4 degrees S, 36.5 degrees W), in the ionospheric minimum virtual height h'F and the maximum critical frequency foF2 at Fortaleza (3.9 degrees S, 38.4 degrees W), and in the TIMED/SABER satellite temperature data in the stratosphere-mesosphere. Wavelet analyses of these time series reveal that the 3-4-day oscillation was observed for all of these data during the period from March 1 to 11, 2005. From the characteristics of the downward phase propagation ( wavelength of similar to 40 km), longitudinal and latitudinal extension, we conclude that this oscillation must be a 3.5-day Ultra Fast Kelvin (UFK) wave. This is the first report of clear evidence of propagation of a UFK wave from the stratosphere to the ionosphere. The UFK wave could have an important role in the day-to-day variability of the equatorial ionosphere evening uplift.