Statistical Characteristics of Cloud-to-Ground Lightning Across Different Regions in China

Characteristics of both positive and negative cloud-to-ground (CG) flashes across different regions in China are analyzed by the CG lightning data acquired from Chinese Lightning Detection Network constructed by power grid. The ratio of negative to positive CG flashes varies significantly across different regions, with the highest ratio (80.4:1) in plateau regions and the lowest (2.56:1) in mountainous areas. The majority of lightning flashes exhibit only one return stroke, with positive flashes showing a higher prevalence of single strokes compared to negative flashes. The average number of strokes per flash ranges from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1. 1 3}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1. 2 7}$</tex> for positive flashes and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{2. 1}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{2. 7}$</tex> for negative flashes. The average inter-stroke intervals for negative flashes range from 80 to 90 ms, with the plateau region having the smallest mean interval and the coastal region the largest. For positive flashes, the average intervals range from 127 to 149 ms, with coastal regions showing smaller average intervals compared to plains and mountainous areas. Both positive and negative CG flashes show a decreasing trend in mean inter-stroke intervals as the stroke order increases. This trend is more pronounced in plateau and mountainous terrains, where the average intervals diminish to below 60 ms when the sequence number rises from 7 to 9.