Lightning climatology across the Chinese continent from 2010 to 2020

Abstract

Understanding the lightning climatological distribution is of great significance but remains challenging which is in part due to the lack of continuous and uniform lightning observations. In this paper, for the first time, an 11-year ground-based cloud-to-cloud lightning dataset of China National Lightning Detection Network from 2010 to 2020 is used to investigate the lightning climatology over China's land area in terms of spatial distribution, seasonal, monthly and diurnal variations. Lightning activity in China's land area generally decreases from south to north and from east to west. The mean cloud-to-ground lightning density of China's land area is 0.9 fl km−2 yr−1, with the average maximums (exceeding 10 fl km−2 yr−1) are found in the south and east coastal provinces, such as Guangdong, Hainan, Fujian and Zhejiang Province. The lightning activity in spring, summer and autumn seems consistent throughout the daytime cycle, with the lightning activity is rather weak in the morning and most active in the afternoon, while winter lightning appears to be more active in the nighttime and in the very early morning produced from nocturnal thunderstorms. The cloud-to-ground lightning activity in the tropical and subtropical areas within 15–25°N is mainly concentrated in the late spring and early summer, with two weak peaks in May and August, while lightning in mid latitudes within 25–55°N mainly occurs in the summer (June–July-August). The percentage of positive cloud-to-ground lightning flashes with peak current higher than 75 kA is more than 3 times than that of negative cloud-to-ground lightning flashes. Meanwhile, the mean peak current of cloud-to-ground lightning flashes shows an inverse diurnal pattern to the cloud-to-ground lightning activity.