Statistical analysis of negative cloud-to-ground lightning characteristics in Bogota, Colombia based on electric field measurements

Abstract

This paper studies the electric field parameters of negative cloud-to-ground (CG) lightning flashes in the Bogota savanna (a large plateau located in central Colombia), and its comparison with other regions. This work is the first of its kind in the country where the parameters of lightning-generated electric fields are analyzed in detail. A total of 329 CG lightning flashes had been examined. These flashes were recorded within 4–250 km from the measuring station during the period August–November 2016. From observations, negative CG flashes comprised 93% of total events registered. It has been found that negative lightning discharges occurred along the plateau (4250 km2 at 2550 m altitude) exhibit some different characteristics compared with measurements carried out in several regions (tropical, subtropical and temperate latitudes). In this study, it was found that 64.7% of the negative CG flashes are multiple strokes with an average multiplicity of 2.58 strokes per flash. In addition, the mean interval between 789 negative return strokes (306 first- and 483 subsequent strokes) was 61.3 ± 51.9 ms, while the arithmetic mean of the total duration for 198 multiple-stroke flashes was 149.5 ms. Other lightning flash features such as relation between the interstroke interval and the return stroke order, the ratio of the subsequent stroke peak field to the corresponding first one and the maximum multiplicity are also analyzed.