This research project involves a modeling study of NOx production by intracloud lighting and its subsequent variability in time and space using the Storm Electrification Model (SEM) developed at South Dakota School of Mines and Technology. The SEM is unique in its features as it pertains to studies of cloud dynamics and microphysics, as well as cloud electrical development, including a parameterization of the production of lightning. The study will include four steps. First, NO will be treated as an inert gas and a vertical profile will be considered. The NO transport within the context of cloud evolution will be evaluated and used later on to sort out lightning enhancement of NO concentration. Second, NO production by lightning will be simulated using ideas of Borucki and Chameides (1984), without any reactive chemistry. Several parameter studies will be performed in order to find answers to questions such as: how lightning-produced NO is transported within the cloud, where the maximum NOx concentration would most probably be located within the cloud, and how lightning location influences the NOx distribution within the cloud. The third step will include chemistry that leads to the production of NO2 following the initial production of NO by lightning. The last step includes reactions of NO with peroxy radicals. This will be the first study that investigates the production by lightning and subsequent distribution of NOx using a sophisticated dynamical electrical model of thunderclouds.
