Quasi-five- and ten-day oscillations in f₀F₂ and their possible connection with oscillations at lower ionospheric heights

The statistical analysis of the 5-day and 10-day oscillations inferred in the upper and lower ionosphere in Central Europe from f₀F₂ measured in Průhonice and the radio wave absorption in the lower ionosphere shows a remarkable degree of similarity for relative amplitudes of oscillations (not for absolute amplitudes). The relative amplitudes in both regions do not express a significant solar cycle effect and their seasonal variation is also similar except for winter. The typical relative amplitude of both 5- and 10-day oscillations in the F₂-region is about 4%, which is useful information for PRIME.