Short-wave communication lines and ionosphere modification

At carrying out of experiments on the modification of an ionosphere in some cases the influence is made at height of layer Е, where electrojet proceed. The influence on a electrojet results in its change of current structures and finally to variations of the Earth magnetic field. On the basis of the consideration of publications devoted to this question, the analysis of geomagnetic conditions and ionosphere data on the example of the sudden blackout with group of the ships taking place to the south and to the north of Alaska latitude, concludes a possible participation in this event of the experiments on the ionosphere modification.