Characteristic analysis of lightning activities on the Yungui Plateau using ground-based remote sensing

Abstract

The spatiotemporal distribution of cloud-to-ground (CG) lightning activities on the Yungui Plateau is investigated in this study by using a 5-year dataset (2016–2020) from the ground-based National Lightning Detection Network (CNLDN). The correlations between the lightning activities and different meteorological factors in the region are also analyzed. The results show that there is an obvious difference in the spatial distribution of lightning activities on the Yungui Plateau during the 5 years, with high lightning density in the east and low lightning density in the west. The lightning activities shift and gather more towards the eastern plateau especially after 2019. Affected by the quasi-stationary front in Kunming, the spatial distributions of lightning flashes in cold and warm seasons are different. On the other hand, the frequency of the lightning activities varies from year to year, such as the surge in 2019. But in general, 62% of the lightning activities are produced in summer and the lightning flashes occur more often in the afternoon and evening on the Yungui Plateau. Additionally, it is found that lightning activities in the 5 years are closely related to precipitation and temperature, while there is a weak correlation with relative humidity and almost no correlation with sensible heat flux. The analysis also indicates that the CAPE×P (convective available potential energy times precipitation rate) proxy can be effectively used to describe and predict lightning activities on the Yungui Plateau as the lightning flashes corresponds well to CAPE×P, especially of the spatial distribution.

Refined risk assessment and differentiated protection of lightning damage in distribution network lines considering the underlying surface environment

“…In recent years, extreme weather has occurred frequently, and lightning activities have become more frequent (Wu and Wang, 2021;Ramesh et al, 2023). The span of the main network pole-tower is generally between 300 m and 500m, while the span of the distribution network pole-tower is generally between 50m and 80 m. Therefore, when the positioning accuracy of the lightning positioning system is 500m, the lightning strike coordinates located by it are more accurate for the main network, but there is a certain deviation for the distribution network (Hu and Xin, 2020;Liu et al, 2022a;Hu et al, 2022;Dementyeva et al, 2023). Unlike the main network, which generally only considers direct lightning tripping, lower amplitude direct lightning and voltage induced lightning may cause the distribution network tripping due to incomplete lightning protection configuration and low voltage withstand level (Shen et al, 2019;Liu et al, 2020;Shi et al, 2021).…”