Ground radon exhalation, an electrostatic contribution for upper atmospheric layers processes

Abstract Radon exhalation from the ground and consequent formation of large ion clusters as a result of ionization and plasma-chemical reactions have been proposed as an agent of seismo-ionospheric coupling mechanisms. Soil radon transfer to the atmosphere was evaluated at fixed stations in Mexico using SSNTD and GPS receivers’ data were used to calculate changes in the ionosphere due to the Ms 7.8 earthquake occurred in Mexico in 2003. An anomaly was observed that can be regarded as the earthquake precursor showing its clear spatial connection with the epicentre position.