Solar and atmospheric variability influences the ionosphere, causing critical impacts on satellite and ground based infrastructure. Determining the dominant forcing mechanisms for ionosphere variability is important for prediction and mitigation of these threats. However, this is a challenging task due to the complexity of solar-terrestrial coupling processes. At high latitudes, diurnal and semidiurnal variations of temperature and neutral wind velocity can be forced from either below (lower atmosphere waves) or from above (geomagnetic and in-situ solar forcing). We analyse measurements from the incoherent scatter radar (ISR) facility operated by the European Incoherent Scatter Scientific Association (EISCAT). They are complemented by meteor radar data and compared to global circulation models. Experimental and model data both indicate the existence of strong semidiurnal oscillations in a two-band structure at altitudes $\lesssim110$ km and $\gtrsim130$ km, respectively. Analysis of the phase progressions suggests the upper band to be forced \textit{in situ} while the lower band corresponds to upwards propagating tides from lower atmosphere. These results show that the actual transition of tides in the altitude region between 90 and 130 km is more complex than described so far.