On the variability within-the-hour and from hour-to-hour of the F-region characteristics above Rome

The statistical analysis of daily 5-minutes f(o)F2, M(3000)F2 and MUF value s, measured at Rome, leads to interesting results regarding the variability within-the-hour and from hour-to-hour of these parameters. There is eviden ce that the relative deviations of the 5-minutes values of these characteri stics from their corresponding nearest hourly daily value are less than +/- 0.10 during the post-dawn morning hours up to sunset whereas around dawn an d sunset hours they are larger. An "intrinsic" fluctuation of more than 3% is always present. (C) 2000 Elsevier Science Ltd. All rights reserved