Study of long duration currents in lightning flashes

Abstract

Cloud-to-ground lightning are responsible for immense material damage and for more than a hundred deaths annually in our country. The lightning flashes that contain currents of long duration, known as continuing currents, produce damage associated with the heating caused by them (burnings, melting of materials, forest fires, damage to transmission lines, etc.). This project aims at the observation and characterization of continuing currents, as well as the characterization of the flashes that contain it and the thunderstorms associated with these flashes. To achieve this objective, in addition to the analysis of the video database obtained by high-speed cameras and electric field data, we intend to carry out new data acquisition that will be complemented by auxiliary sensors (infrared video camera, interferometry, Lightning Mapping Array, electric field sensors, atmospheric electrostatic field sensors, electrical current sensors, photometers, lightning location systems, radar and satellite data). The joint analysis of old and new data from different countries will serve to characterize important parameters of the continuing currents (frequency of occurrence, duration, intensity, etc.) as well as of the flashes that produce it (polarity, multiplicity, etc.) and associated thunderstorms (top height, horizontal extension, stage of development, etc.). This study will be able to better define these parameters and thus help in the validation and improvement of the knowledge used in areas such as: the occurrence of heat damages and fires caused by lightning, the design of lighting protection systems, the estimation of the production of gases that influence the chemistry of the atmosphere, the production of transient luminous events (TLEs), the initiation of upward flashes, etc. (AU)