Context:
Soaring global temperatures could lead to more “hot lightning” strikes in many parts of the world, a new study has found. It added that this type of lightning is more likely to ignite wildfires than typical lightning.
Relevance:
GS Iii: Environment and Ecology
Dimensions of the Article:
- Study finds link between hot lightning and wildfires Points
- What is lightning and how does it occur?
- What is wildfire?
Study finds link between hot lightning and wildfires Points:
- Researchers analysed over 5,800 lightning-ignited fires in the US between 1992 and 2018 and found that around 90% of them may have been started by hot lightning strikes, also known as long continuing current (LCC) strikes.
- Hot lightning strikes can transport more energy from cloud to ground than typical lightning, making them more likely to ignite a wildfire upon hitting the ground or vegetation.
- Computer simulations showed that as the atmosphere warms, there could be a 41% increase in LCC strikes by 2090, potentially leading to a 28% jump in all cloud-to-ground strikes.
- The areas most likely to see an increase in wildfires triggered by LCC strikes are Southeast Asia, South America, Africa, Australia, North America, and Europe, while some northern polar regions may see a decrease due to increased rainfall.
- The researchers suggest that climate change and its impact on the frequency and type of lightning strikes could have significant implications for wildfire risk in the future.
What is lightning and how does it occur?
- Lightning is a rapid and massive electrical discharge that takes place between storm clouds and the ground, or within the clouds themselves.
- Lightning occurs when positive and negative charges separate within a cloud, creating a system of positive charges at the top of the cloud and negative charges at the base, with the atmosphere between them acting as an insulator.
- When the positive and negative charges become strong enough, they overpower the insulating properties of the atmosphere, and the two kinds of charges meet, producing lightning.
- Most lightning occurs within the clouds, but sometimes it is directed towards Earth, with the base of the cloud becoming negatively charged and positive charges accumulating on tall objects.
- The lightning stroke occurs when a “stepped leader” of negative charge descends from the cloud and a positive charge, called a streamer, reaches up to meet it, forming a connection.
What is wildfire?
- A wildfire is an uncontrolled fire that burns in the wildland vegetation, often in rural areas.
- Wildfires can burn in forests, grasslands, savannas, and other ecosystems, and have been doing so for hundreds of millions of years.
- They are not limited to a particular continent or environment.
What causes Wildfire?
- Wildfires require right climatic conditions, burnable fuel and a spark.
- Rising temperatures suck moisture out of plants, creating an abundance of dry fuel.
- Drought and high heat can kill plants and dry out dead grass, and other material on the forest floor that fuel the fire once it starts sweeping through a patch.
- While dry vegetation is the burnable fuel that serves as kindling for fires, the spark is sometimes caused by lightning, at other times by accident or recklessness of the local population.
-Source: Indian Express
