Electrodynamic model of the lower atmosphere and the ionosphere coupling

Electrodynamic model of the ionosphere response to seismic related lower at mosphere disturbances is developed. The chain of processes forming the lith osphere-ionosphere coupling starts from the injection of radioactive substa nces and charged aerosols into the atmosphere. This leads to a change of th e vertical electric current in the atmosphere and to modification of the el ectrical field in the ionosphere. Growth of the electric field and related development of acoustic-gravity wave instability is followed by formation o f field-aligned currents and plasma density disturbances stretched along th e geomagnetic field. Another effect of the electric field increase is an ad ditional Joule heating of the lower ionosphere which results in an elevatio n of the F-layer maximum, a decrease of electron density in the maximum of this layer and a growth of light ion density in the upper ionosphere. Thus, the presented model connects disturbances of the key ionosphere parameters with increase of atmospheric radioactivity and injection of charged aeroso ls into the atmosphere. (C) 2001 Published by Elsevier Science Ltd.