Time variation of cloud-to-ground lightning activity in several geographical regions of Colombia: A comparative analysis with different latitudes

Abstract

This paper presents a description and characterization of the lightning activity over the central and northern portions of the Colombian territory, which was divided into nine subregions for the analysis, between 2007 and 2016. The lightning activity and parameters within the study areas display a high level of temporal and spatial variation; however, these variations are overshadowed when the analysis is conducted for larger areas. In the northern regions, the monthly lightning activity follows a unimodal distribution, whereas in the central and southern regions, it follows a bimodal distribution. The majority of the lightning activity occurs during the afternoon and evening (local time). Regarding the lightning peak current, the polarity percentage was observed to fluctuate slightly between 80 and 20 percent for negative and positive flashes respectively. In certain regions, this percentage varies only in isolated cases and cannot be interpreted as a rule. Positive flashes have a multiplicity of 1 stroke per flash, whereas negative flashes have a multiplicity between 1 and 2 strokes per flash. For most subregions, the Cloud-to-Ground Lightning Flash Density (CGLFD) displays large variations with maximum values above 30 flashes km⁻² year⁻¹. CGLFD and altitude correlations did not exhibit a uniform pattern, however, in certain regions, the CGLFD and altitude display an inverse relationship. Additionally, a comparative analysis of the lightning parameters found in this study is performed with the values reported at other latitudes.