A NUMERICAL STUDY OF THE EFFECTS OF AEROSOL ON ELECTRIFICATION AND LIGHTNING DISCHARGES IN THUNDERSTORMS

Abstract

Based on existing three-dimensional (3-D) thunderstorm electrification and discharge model, this work coupled with a classical parameterization scheme of aerosol activation is used to simulate a case of tropical convection in Changchun. The study shows that the change of aerosol concentration has an important influence on the microphysics, electrification and discharge processes of thunderstorm clouds. The results show that: (1) As the aerosol concentration increases in the polluted thunderclouds, the increase of the number of cloud droplets and the updraft cause the increase of the number of ice crystal and graupel, but the decrease of the scale; (2) Compared to the clean thunderclouds, the non-induced electrification process is weak, while the induction electrification process is strong, and the duration of electrification become longer in polluted thunderclouds; (3) The first charge time of the polluted thunderclouds delays, but the total lightning frequency increases and duration is longer. Meanwhile, the frequency of the cloud-to-ground flash in the polluted thunderclouds increases, and the increase of the positive cloud-to-ground flash is more obvious.