Fig. 3

The proportions of CGs with Ip > 30 kA out of the total number of CGs recorded over the period 2018–2021 globally (blue line) with Ip > 2 kA, over the continents (green line) and over the oceans (orange line). The black dashed curve represents the ratio of CGs with Ip > 30 kA over the oceans (sea) and continents (land). The black and red dashed lines indicate the proposed proportions of SBs out of the total number of CGs with Ip > 2 kA.