Modification of the lower ionospheric conductivity by thunderstorm electrostatic fields

This paper reports a modeling study of the modifications of the nighttime lower ionospheric conductivity by electrostatic fields produced by underlying thunderstorms. The model used combines Ohm?s law with a simplified lower ionospheric ion chemistry model to self-consistently calculate the steady state nighttime conductivity above a thunderstorm. The results indicate that although the electron density is generally increased, the lower ionospheric conductivity can be reduced by up to 1?2 orders This paper reports a modeling study of the modifications of the nighttime lower ionospheric conductivity by electrostatic fields produced by underlying thunderstorms. The model used combines Ohm's law with a simplified lower ionospheric ion chemistry model to self-consistently calculate the steady state nighttime conductivity above a thunderstorm. The results indicate that although the electron density is generally increased, the lower ionospheric conductivity can be reduced by up to 1-2 orders of magnitude because electron mobility is significantly reduced due to the electron heating effect. For a typical ionospheric density profile, the resulting changes in the reflection heights of extremely low frequency and very low frequency waves are 5 and 2 km, respectively. Key Points: Self-consistent calculations indicate that thunderstorm DC fields can modify the lower ionosphere Electron density increases up to four to five times but conductivity decreases up to 2 orders of magnitude The changes in reflection heights of ELF and VLF waves are 5 and 2 km, respectively ?2015. American Geophysical Union. All Rights Reserved. 2016 10.1002/2015GL066933 Research Letter Research Letters Space Sciences