Theoretical and Numerical Study of Electrohydrodynamic Generation of Atmospheric Turbulence

Ionization produced by cosmic rays and atmospheric radioactivity creates charged short life-time aerosols. The high variability of these aerosol particles leads to time varying electric fields and space charge in the atmosphere, which can often be amplified by more than three orders of magnitude in extreme conditions, such as thunderstorms. The nonlinear coupling between ionized particles, cloud droplets, and the background electric field can result in a body force due to electrohydrodynamic (EHD) interactions. Although the EHD effect has been widely shown to induce turbulence in various engineering systems, its effect on atmospheric turbulence remain elusive. In this presentation, we investigate the effect of EHD on atmospheric turbulence under both fair-weather and thunderstorm conditions. A linear stability analysis is performed to understand the stability criteria, relevant non-dimensional numbers, and time scales for EHD-induced turbulence. Then simulations are carried out with relevant atmospheric parameters at 6 km altitude to understand the effect of non-linearity on turbulence generation. The turbulent kinetic energy budget and growth rate are reported to assess the significance of EHD for a range of particle charges and background electric fields.