Numerical Studies of Thunderstorm Electrification, Maxwell Currents, and Lightning

South Dakota School Of Mines And Technology, Rapid City SD

Investigators

Abstract

This project continues the research initiated earlier on the numerical modeling of clouds including parameterizations for electrical charging, charge separation, and lightning. It includes the analysis of cloud electrical and microphysical data collected by the storm-penetrating T-28 aircraft during the STEPS program (Severe Thunderstorm Electrification and Precipitation Study) conducted in Kansas in the early summer of 2000. The existing cloud model will be improved by addition of a more accurate treatment of microphysics, apart from electrical effects, and by experimenting with different parameterizations for the non-inductive charging mechanism. The model will be validated by comparison with observations of thunderstorms from STEPS and other field programs. A new objective is to compute Maxwell current vectors as part of the simulations as a way to test hypotheses that relate thunderstorm activity to the global electrical circuit. The work advances the understanding of thunderstorms by providing a comprehensive and self-consistent numerical model that enables the simulation of charging, lightning, and precipitation under different environmental conditions.