Incoherent scatter radar study of the terdiurnal tide in the E- and F-region heights at Arecibo

We report the analysis of the terdiurnal tide in the meridional wind from 90 to 350 km at a low latitude station. Our data is based on nine days of consecutive observation made by the Arecibo incoherent scatter radar during January 14-23, 2010. The terdiurnal tide is observed to be prominent at E-region heights in the first four days (Jan. 14-18) and at the F-region heights in the last five days (Jan. 18-23). The terdiurnal tide is among the two strongest tidal components in both regions. The vertical wavelength of the terdiurnal tide is about 100 km, and 950 km, for the altitude range of 128 to 142 km, and 180 to 320 km, respectively. The F-region terdiurnal tide amplitude is found to be well correlated with the background meridional wind in the lower F-region. Our analysis does not reveal any evidence that non-linear interaction between diurnal and semidiurnal tides is important for the F-region terdiurnal tide.