Characterization of M components and leaders of natural lightning from high-speed video observations and atmospheric electric field measurements

Abstract

This research project consists in combining observations obtained through high-speed cameras and atmospheric electric field measurements in order to study two physical phenomena involved in the production of natural cloud-to-ground lightning: M components (pulses that occur during the continuing current and whose peak current value, obtained from triggered lightning experiments, can range from hundreds to a few thousands of amperes) and leaders (responsible for ionizing and making the lightning channel conductive). We intend to use a previously developed software to obtain luminosity-versus-time curves of each flash from the video recordings and correlate these data with "slow" electric field measurements (whose integrator circuit has a longer time decay constant) in order to estimate intensity-related parameters of M components. We also expect to be able to correlate data on the development of leaders by observing them simultaneously through the cameras and the "fast" electric field sensors (whose time decay constant is shorter) in order to analyze their fine structure and obtain qualitative and quantitative relations between the data provided by both instruments. After characterizing these phenomena from the data provided by the instruments, we expect to be able to analyze in a critical way the existing physical models developed to describe and explain them, proposing eventual revisions or reformulations that might be necessary.