Singapore
June 2013
Merlion Wayfarer was awaken by the bouts of thunder this morning. They came frequently, at a low rumble through the night. Frustrated, she opened the curtains.
This is what she saw...
She was curious - Unlike light, lightning does not travel in a straight line. Instead, it has many branches...
These other branches flashed at the same time as the main strike. Next you notice that the main strike flickers or dims a few more times in a single split second. The branches are actually the step leaders that were connected to the leader that made it to its target.
When the first strike occurs, current flows to neutralize the charge separation. This requires that the current associated with the energy in the other step leaders also flows to the ground. The electrons in the other step leaders, being free to move, flow through the leader to the strike path. So when the strike occurs, the other step leaders are providing current and exhibiting the same heat flash characteristics of the actual strike path. After the original stroke occurs, it is usually followed by a series of secondary strikes. These strikes follow only the path of the main strike; the other step leaders do not participate in this discharge.
It is very possible that the main strike is followed by 30 to 40 secondary strikes. Depending on the time delay between the strikes, it may look like one long-duration main strike, or a main strike followed by other flashes along the path of the main strike. The secondary strike can occur while the flash from the main stroke is still visible. Obviously, this may seem that the main-stroke flash lasted longer than it actually did. Similarly, the secondary strikes may occur after the flash from the main strike ends, making it appear that the main strike is flickering.
