Investigation of the influence of seismic activity on the semi transparency coefficient of the sporadic es layer over kamchatka

Small-scale turbulization of the sporadic Es layer (tens of meters) is estimated by the semi transparency coefficient $\Delta$f bEs, and large-scale turbulization (hundreds of meters) is expressed in Es scattering. It is known that before large earthquakes with magnitudes M\ge 5.0, the formation of abnormal sporadic layers in the E region can be observed: an increase in the electron concentration and semi transparency coefficient at the interval from 14 to 3 days before the earthquake and a subsequent sharp decrease in the values of these parameters 1 day before the earthquake. This paper analyzes changes in the semi transparency coefficient of the sporadic Es layer preceding the onset of earthquakes with a magnitude M\ge 5.0 that occurred in the Kamchatka region during the period 2015–2019. The prognostic efficiency of the parameter $\Delta$f bEs was evaluated using the methods of A. A. Gusev and G. M. Molchan.