The research is aimed at understanding how lightning rods work to dispel lightning discharge from the sky saving key infrastructure and human lives.
New Delhi,UPDATED: Mar 29, 2023 12:09 IST
By India Today Science Desk: In what is one of the most stunning images ever captured, Brazilian scientists have recorded lightning in the sky being attracted to an upward discharge from a building. The discharge was beamed less than a millisecond before the lightning bolt touched the rod revealing an elusive phenomenon that has long protected humans and assets from lightning strikes.
The research is aimed at understanding how lightning rods work to dispel lightning discharge from the sky, saving key infrastructure and human lives. The research could further enhance the protection system used in high-rise buildings to prevent them from being hit by lightning.
The close observation of the event has now revealed details of the lightning attachment process to residential buildings in highly populated areas. Researchers said that the effectiveness of a lightning protection system depends on its efficiency to intercept the downcoming lightning leader which is usually done by emitting an upward connecting leader (UCL).
Researchers captured the upward discharge and the attracted downward lightening in Sao Jose dos Campos city, which is northeast of Sao Paulo in Brazil. They observed and recorded 31 of these upward discharges in the minute moments before the lightening strike. The team used a camera that could capture 40,000 images in a second and recorded slow-motion videos.
The details helped them understand what happens in the moments before the charge from the lightning rod on the building meets the charge coming from the lightning.
They found that the upward discharge moved in an almost straight line with no branching with a uniform corona brush. However, the downward discharge from the lightning bolt had substantial branching and numerous filaments. They also identified space stems, which plays a key role in the stepped propagation of lightning bolt.
The study published in Geophysical Research Letters states the observations indicated that the space stems hamper the leader propagation, making the upward connecting leader intercept a different downward branch, which was originally more distant from the striking point.
"Events that initiate an upward leader but fail to make contact with the downward leader, are also of great importance in lightning protection. They can cause damage to equipment vulnerable to sparks or induced currents, and may be powerful enough to injure someone," the paper read.
The images revealed that the upward discharge was not only being created by the lightning rods placed on the buildings but also by different corners of the building. Researchers said that any person standing in an open area can also y launch an upward connecting discharge from their head or shoulders and could be injured.