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=ASIA6AP2G7AKDKDSK32F%2F20260305%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20260305T184522Z&X-Amz-Expires=3600&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEAgaDGV1LWNlbnRyYWwtMSJHMEUCIHZNSHV9qAn9G%2FYdEeJzoqWDC%2BhxfvvjikV%2FiftG%2B7cIAiEA9nIRXSbm3%2Ffz0F0s52IkQmcdCrKveqt2hoPZ3GYSCLUqxgUI0f%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FARACGgw5NjMxMzQyODk5NDAiDHuiXmauKnNDATpnUyqaBXY4VMnAFI4WxpQ031%2FKf6xUqPd4t3OVQPTu4QCrLUUWsxKm%2BBtwr23mWf78kkIawLxP0foRJuaWKCJIcgYGGcWx6GNc30wOFycuXr35zTECwU%2FSXxUnON3EXnuTPR%2Ben7QqW94wP2YwXSb1F99N%2Bb9GYUhE8AB6bzZfjeGsqYUKIdB4VYcaeMbEcJSFS7X1IU3cTLktkuiWcj2Vh%2BfzdE%2BJxpTS0EssORNf5Pe%2FBjt2%2FEURqqdEeBx7xrE19etH%2BcYKJcK1Lvv47zpsusSTQW8wLWH2OeMDvrn%2FR6QLAHywnOthnZvcQh8QpQeI1YbZDB0dyEAkvBDbEz5J3uPP%2F0elei8ln5VHgS%2BzGl3QZV7d9VP%2BiWEO2vVluB6kFAP6jhSLcNh3NpngByusvjOGurMf7HGlm3QNCS9G5caG1dv1ZWoKWYIAi%2BXjj1Nw1loK78Vq8XNweAKnY0YRr%2F2XSuBytJsJXZv1VplWhFFaEvJCBlhsLyB6jiVKMf9jdq%2BkFj%2FNddJWE8MlKPBhd5Z9X9%2BN%2FFVUZNIRlqJvL5CR8Ydp4h3ew21NtbGb9Bpo9kLOm1AlmpxisFJmSr6189V%2Ftv2xfvSuU%2FvqJLVcgsJVNEljZULestsMXLafFGec8DhQ22%2BbqsIhjm3uarBfWOWG4ptYoCiHiWkdVegj9TxYdG3U8T7Kw9tJlggt717A9gn%2BHHM6VXKthht6CN2ULazdLLgDGfPUp%2BBX96SVjRMCTJd8rDpbAE5Chw8JZ8qyyPGVRjQzIjh9OI%2FY2nQ0%2F%2B8yKOKJO6QNKuamjJgoplwkUmWqfyI%2FnzgnFo6jNRx1YP5FH7npxwSj040k4yX9i6vzCTE7fbuJ7SXZLrBdrzmIbXCAbsNhKbSMSZySwjD8y6bNBjqxAfE8I%2BqXkOwbhxdftbkNjmM1Tk5trpu5EL%2BYDc8GS%2B1QJOlrbfdhh%2BK8wwzTUG4l9GCkoF9sUbIrnaBYYfqwJu7z4KKfmG%2FN8%2BUjF0w19AMco079L8%2BW3QengL8E4gBK9rE%2FfcTwWzOodVu799yYHHFreo0DgJrxGNmV0zZMtXOmNTH4gQA6UjijmDgq3sH0OzctFGkfhQ6WqmCpdqaurL1bjVFRo77yyqu3j5DV85tR1w%3D%3D&X-Amz-Signature=dfaeb8975e9c04399e65c8e61417759b7c7f1f2223ca0e247c9e96b2dacc15ca&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 |