Change of ionospheric plasma parameters under the influence of electric field which has lithospheric origin and due to radon emanation

Abstract A mechanism of electric-photochemistry channel of seismo-ionospheric coupling is investigated. In particular, the penetration of electric field from the lithospheric source into the ionosphere and effect of this field on the photochemistry coefficient and ionospheric parameters in the altitude range in the lower D region are modeled numerically. It is shown that observable effects can be expected when lithospheric electric source strength is of the order of 1.5 kV/m. In this case, variations of electron temperature and electron concentration will be of the order of (40–60)% and (25–40)% respectively at the range of altitudes 60–70 km. An increase of near-ground conductivity (caused by increasing humidity and/or radon emanation) by ∼2.3 times can cause increase of electric field intensity by ∼2 times in altitude ranges of 60–70 km. Corresponding relative change of T e increases up to ∼50%, as compared with the case of lower near-ground temperature. Spatial shapes of relative distribution of electron temperature and the ratio of negative ion–electron concentration map the spatial shape of the lithospheric electric field distribution. Spatial shapes of electron concentration distribution and electric field strength distribution of the lithospheric source are “opposite” to each other.