Ensemble Simulation of the Lightning Flash Variability in a 3D Cloud Model with Parameterizations of Cloud Electrification and Lightning Flashes

Abstract

A series of ensemble simulations were performed to study the statistics of flash characteristics produced by an electrification and lightning scheme in the cloud-resolving model Méso-NH. Here, the electrical variability of two storms?one supercellular and one multicellular?results from a random triggering location of the flashes and from a branching algorithm that describes the flash path. The study shows that the electrical model is able to generate several estimates of the total flash number for an identical evolution of the dynamics and microphysics of each storm in the 120 ensemble members. The variability of the flash number spans over three standard deviations taken from the ensemble mean. The simulations produce regularly shaped distributions of flash internal parameters (i.e., number of segments and branching levels per flash). The ensemble simulation shows that the model is stable and self-regulatory as suggested by the limited overshoot on the maximum electric field time series. An application to the production of nitrogen oxides indicates that the two storms produce 200 ± 150 mol of NO per flash on average.