Effect of hour marks in activity of Pel electromagnetic oscillations as evidence for human impact on the ionosphere and magnetosphere

We have given examples of dynamic spectra of Pclelectromagnetic oscillations (0.2-5 Hz), which indicate that the so-called effect of hour marks (HM) occurs sporadically in the activity of not only pearls but also of other well-known species of Pc1, namely resonances. The HM effect is manifested in both the species in a similar way: the beginning of an hour in universal time serves as a signal giving rise to physical processes which in some cases lead to a drastic change in the oscillation mode. In the case of pearls, dynamic spectra show clearly that the oscillations are "plugged in" or "off" immediately after the advent of HM. In the case of resonances, one should rather speak of a sharp strengthening or weakening of the oscillations. Switching from pearl mode to mode of resonances, back and forth, can occasionally be observed at the instant of HM occurrence. The HM effect certainly indicates a noticeable force and/or thermal pulse technosphere action on near-Earth space. The general idea is that the beginning of every hour globally synchronizes the operation of technology systems, resulting in a sporadically observed HM effect. It is emphasized that the observed HM effect has posed very difficult questions for ionospheric and magnetospheric physics in general and for the Pc1 theory in particular.