Fig. 1.

Fig. 2.

Fig. 3.

Fig. 4.

Fig. 5.

Fig. 6.

Fig. 7.
![The mutual relation between 2002 and 2023 CG lightning stroke density (left panel – both lightning stroke polarities]) and LDI (right panel) of the same period.](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/647351904e662f30ba539f38/j_quageo-2025-0029_fig_007.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=ASIA6AP2G7AKB3E67D57%2F20260122%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260122T072543Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEAoaDGV1LWNlbnRyYWwtMSJHMEUCIHTNfYedDUdDVZWwbsI582O5noWkHkXSmsImqtTR9kocAiEAo7cEy%2FaUWEFqbb6Uu71GIluaST5UagjSzPH1bgZO7PAqxgUI0%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FARACGgw5NjMxMzQyODk5NDAiDFYyR9p4024lY2YrlCqaBe6gSiwPs0zPYGAuIDy8s8DuW%2Fl2AR2vJ8V%2FCgOCLQrrTCfTkzY%2B2HTJc9VIVg%2FR%2BOGBArhfy5onrY%2Bnos3ag7Q4m9gUWkU5FEN6i0M7bL9%2B%2FF%2F%2BzKO69v3FWvzfRNqYvoUCKlE%2FTG0CQc5%2FCb%2Fet%2FZ3nHSrmTSW4afDBV4%2F2sdDuk2Y7j1%2FiSOdEAsAUkLxNaT8%2BYY0uzXR2U7tVROer6ZxFJEzMzvMGRWlNbg4aPXygFeSZRhUnf66pHR9Qif8HVwhrrthIUPXJKZPSGqbmSEVz%2FAg80%2Fn3aCrOMNwcqdYy3tkRVCPE2DgNN0Psj%2B0GA2A%2BansdSkNHSEd60TfZlR5JhpR6pxxU0gkXgkTVtPLcR8kVTPduS9%2FZw0b2CUNmjkxNhPu%2FoqDNZIKeSH3eJ%2BDEPAGJ7iWW88ZeVoPC7KZTPrNGGlqSu2JE%2FXqKLbrlC8mR%2BEn66wslULo1ztQ4pSz0u5788zr%2FiCPJQRoTXcgLiSXm7Y39qALq84qY1oRurK2FG%2Bgq%2BJuauKBuPBOMcKqX4qYLplaYHNIPq23ecmmWSJjRsgPziQsMh%2FfOu8TcwgYH3nj0urdg904CBXXCALvS8bbfRlNrW7jh9%2BC8mMTKhpp088mDXE%2BSTtvmJpgznQ%2FAukQGRV6b69Iz2mo%2Baq4Zu6vSK2qeQw%2Fkxy3ywOmvV3O5jdozNP3E7lOZC%2BUSCFCrUuZSidr5NqjDuhzRgQmICGYvif94lXywDxKti4CY7Gc09Rvi120CeeKB7BuoxFW1fOhk1UD9po%2Bx6VCYIsHMazwsdDsf6qqIUQ4GSjr2dPNs7j4CZdAY0D%2FkQF2OmZKTgRx1yKUmoRqkjvC7S%2Fhe3gegWop35Lk0rSRbgV%2Big9AydkfzGPRqjDwkMbLBjqxAYgujYLW%2FTYIEG1yQKh3rR86Pw3ZMS6%2BVvuRZC6rcJc%2Bt8XzBLxkWDfz1RcvhGwy8DKblOZSjxZ7RFjrc8SJ3Gmr6NWFaHd6wuhMaz%2BqSLB8a1QJlmr80lX55ADLIj%2Fd5HJNMaOb4NoKtSx07Dpq02bbK3cE0nbyLTHhZ2M9c5bPX7Qa%2Fpm81H9jwPwdffmOtKfX1ugUs5aigkoQPrzWNVVUKqg1p3qMCqalLN9zxrCmig%3D%3D&X-Amz-Signature=ce96b1cb93386ea6320b43c1b3693fc31bc1d764bf6663e5ced72a38fd5e957f&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Fig. 8.

Linear regression equation (y = ax + b) and determination coefficient (R2) calculated for both CG lightning stroke polarities throughout all analysed periods_
| Month | Lightning stroke polarisation | |||
|---|---|---|---|---|
| CG+ | CG– | |||
| y = ax + b | R2 | y = ax + b | R2 | |
| January | y = 13.879x + 3.66 | 0.6181 | y = –11.31x – 64.467 | 0.2391 |
| February | y = 14.863x + 13.61 | 0.3034 | y = –10.373x – 30.107 | 0.2824 |
| March | y = 11.839x + 147.99 | 0.4005 | y = –6.4458x – 164.47 | 0.1545 |
| April | y = 22.99x + 148.22 | 0.4399 | y = –7.3853x – 226.65 | 0.4459 |
| May | y = 12.473x + 233.57 | 0.6575 | y = –5.1407x – 270.09 | 0.2713 |
| June | y = 15.614x + 216 | 0.5637 | y = –8.3806x – 247.83 | 0.3875 |
| July | y = 13.932x + 221.91 | 0.6835 | y = –12.032x – 227.91 | 0.6370 |
| August | y = 10.588x + 241.13 | 0.5576 | y = –6.3636x – 259.84 | 0.4303 |
| September | y = 13.974x + 206.04 | 0.6347 | y = –7.6922x – 238.83 | 0.6388 |
| October | y = 7.1687x + 210.76 | 0.3345 | y = –4.3605x – 245.87 | 0.1555 |
| November | y = 9.7656x + 94.167 | 0.3599 | y = –16.427x – 49.258 | 0.5741 |
| December | y = 13.813x + 31.565 | 0.5812 | y = –12.436x – 67.113 | 0.3457 |