1. Possible effects of radon releases on atmospheric conductivity and currents Fanfan Su, Art Richmond, Wenbin Wang 2015.06.16

2. Content Pre-seismic radon emanation Coupling mechanism

3. Pre-seismic radon emanation Radon concentration increases:  a peak 10 times larger than that at the beginning of the observation, at Japan Kobe, [Igarashi G. et al., 1995, Science]  background level: 650 Bqm -3 ; bursts amplitudes: 2,000 to 18,000 Bqm -3 (27 times), at France Alps, [Trique M. et al, 1999, Nature]

4. Pre-seismic radon emanation Positive values are the maximum relative increasing of Radon concentration, and negative values are the decreasing percents. These samples were from stations all over the world [Hauksson E. et al., 1981, JGR] Radon concentration increases:

5. Pre-seismic radon emanation Distance from the epicenter:  for the preceding large earthquakes (M ≥ 6) 100 to 500 km. These samples are from the stations all over the world [Hauksson E. et al., 1981, JGR]

6. Pre-seismic radon emanation How fast?  spike like ~6 hours [Teng T. et al., 1980, JGR]

7. Pre-seismic radon emanation How fast?  long duration more than one day [Teng T. et al., 1980, JGR]

8. Coupling mechanism [Harrison et al., 2010, JASTP]

9. Coupling mechanism [Harrison et al., 2010, JASTP] Total surface air conductivity:

10. Coupling mechanism Response of atmospheric electrical parameters to changes in the production of surface layer radon ionization. (A value of 1.0 corresponds to 4*10 6 ions m -3.) (left) Total air conductivity at the Earth’s surface. (right) Conduction current density Jc. Solid lines represent clear weather. Dashed lines represent polluted air. From [Harrison et al., 2010, JASTP]

11. Summary Is it possible for Radon to have an effect on the ionosphere? Is it helpful for seismic - ionospheric research? Your comments and possible collaboration.

12. Thank you!