Feedback of electric field force and electrification on kinematic, microphysics, and precipitation in thunderstorm

Numerical simulations are performed to investigate the effect of electric field and electrification process on dynamic, microphysical, and precipitation in thunderclouds. A three-dimension (3D) convective cloud model with electrification and discharge scheme is used to explore the differences between kinematic, microphysical process, precipitation, and lightning activity. The results show that the electrification process significantly enhances the updraft before the first discharge in thundercloud, but the electric field force has a significant effect on the updraft after the first discharge. The influence of electric field force on the formation of precipitation is greater than that of electrification process, and the increase of ice crystal terminal velocity is helpful to the formation of liquid precipitation, and then the increase of graupel terminal velocity is beneficial to the development of solid precipitation. The results also suggest that the new scheme of graupel terminal velocity enhances the high-concentration region of graupel before the first discharge, and the region lasts as long as 10 min, which effectively promotes the production of raindrop in the whole troposphere at specific time. Additionally, the electric field has the most significant effect on the velocity of smaller particles, and an increasing of ice crystal fall speed above 0 °C is also helpful to the formation of lightning. Moreover, it is found that the electric field force enhances the collision and coalescence between cloud droplets/raindrops and graupel during the mature period of thundercloud.