Features of lower ionosphere dynamics conditioned by morning solar terminator

Experimental investigations into the electron density variations in the middle latitude D-region during the morning solar terminator passage have been conducted applying the partial reflections technique. Approximately 50-150% increase in the electron density was discovered during the morning solar terminator passage and afterwards. Within the context of the hypothesis for electron eruptions from the magnetosphere, calculations have been carried out, and a possible mechanism for the electron eruption caused by the morning solar terminator has been shown.