What Is Reverse Lightning? Is It As Dangerous As Normal Lightning?
Reverse lightning, despite its name, isn’t lightning striking backwards. Regular lightning channels electricity from clouds to the ground, a familiar sight during thunderstorms. In contrast, reverse lightning is a less common phenomenon where an electrical discharge shoots upwards, from the ground into the sky.
While it sounds unusual, reverse lightning isn’t a powerful threat compared to its downward counterpart. Let’s delve deeper into this phenomenon.
What is Reverse Lightning? What Causes Reverse Lightning?
Reverse lightning, also known as “inverted lightning,” is a rare and poorly understood phenomenon where the return stroke of lightning appears to originate from the ground rather than the cloud.
This occurs when a lightning channel is initiated by an electrical discharge from the ground up, rather than from the cloud down, creating a reversed flow of electrons. Reverse lightning is often associated with unique lightning phenomena, such as “superbolts” or “gigantic jets,” and is of significant interest to scientists due to its potential to provide insights into the fundamental physics of lightning formation.
Technical Information on Reverse Lightning
There are key distinctions between reverse lightning and the familiar cloud-to-ground lightning:
- Direction: Regular lightning travels downward, following a path of least resistance towards the ground. Reverse lightning, on the other hand, travels upwards along the already ionized channel created by the initial discharge.
- Duration: Reverse lightning is incredibly brief, lasting only milliseconds. In comparison, the entire illumination from the initial discharge to the ground, including the reverse stroke, can take tens to hundreds of milliseconds.
- Cause: The buildup of electrical charge within a cloud initiates regular lightning. Reverse lightning is a consequence of that initial discharge. As the downward leader (the initial channel) connects with positive charges on the ground, a powerful current surges back up the channel, creating the bright flash we see as reverse lightning.
Factors influencing reverse lightning include the electrical properties of the atmosphere, particularly the distribution of charge within the cloud and on the ground. The shape of the initial lightning channel can also play a role, with a more stepped leader potentially leading to a more prominent reverse stroke.
Analyzing Risks Associated with Reverse Lightning
While both types of lightning involve electricity, the danger levels differ significantly.
- Assessing Risks to People and Infrastructure: Regular lightning carries a much higher current, sometimes exceeding 30,000 amps. This immense power makes it far more dangerous to people and structures. A direct strike from regular lightning can cause severe injury, property damage, or even death. Reverse lightning, due to its short duration and lower current, poses minimal risk to people on the ground. The current involved is typically just a fraction of what’s seen in a regular strike.
- Exploring Potential Impacts and Consequences: Though not a direct threat to people, reverse lightning can potentially damage tall structures like skyscrapers or transmission towers. The upward surge can disrupt electrical currents within the structure, causing malfunctions or equipment damage. In some cases, it might even cause minor physical damage at the point of contact, like scorching or melting a small area on the structure.
- Discussing Strategies for Mitigation and Prevention: There’s no specific way to prevent reverse lightning, as it’s a consequence of a regular lightning strike. However, general lightning safety measures like seeking shelter indoors during thunderstorms and avoiding tall objects still apply. Additionally, proper grounding systems on tall structures are crucial. These systems provide a safe path for the current from a lightning strike, including the upward surge of a reverse stroke, to dissipate harmlessly into the ground.
Is It As Dangerous As Normal Lightning?
No, reverse lightning is not as dangerous as normal lightning. Regular lightning carries a much higher current, making it far more likely to cause injury, property damage, or even death. In contrast, the current in reverse lightning is a fraction of that, posing minimal risk to people on the ground.
