A form of lightning with a knack for sparking wildfires may surge under climate change.
An analysis of satellite data suggests “hot lightning” — strikes that channel electrical charge for an extended period — may be more likely to set landscapes ablaze than more ephemeral flashes, researchers report February 10 in Nature Communications. Each 1 degree Celsius of warming could spur a 10 percent increase in the most incendiary of these Promethean bolts, boosting their flash rate to about four times per second by 2090 — up from nearly three times per second in 2011.
That’s dangerous, warns physicist Francisco Javier Pérez-Invernón of the Institute of Astrophysics of Andalusia in Granada, Spain. “There will be more risk of lightning-ignited wildfires.”
Among all the forces of nature, lightning sets off the most blazes. Flashes that touch down amid minimal or no rainfall — known as dry lightning — are especially effective fire starters. These bolts have initiated some of the most destructive wildfires in recent years, such as the 2020 blazes in California (SN: 12/21/20).
But more than parched circumstances can influence a blast’s ability to spark flames. Field observations and laboratory experiments have suggested the most enduring form of hot lightning — “long continuing current lightning”— may be especially combustible. These strikes channel current for more than 40 milliseconds. Some last longer than one-third of a second — the typical duration of a human eye blink.
2023-02-28 08:00:00
Original from www.sciencenews.org
Climate change is an issue that is creating increasingly intense and difficult to predict weather events. In addition to the droughts, the floods and the hurricanes, the phenomenon is also linked to the formation of another destructive force: incendiary fires fueled by lightning strikes.
The World Meteorological Organization has already established a link between climate change and lightning strikes, stating that as the atmosphere warms, it contains more moisture—creating the perfect set up for lightning producing clouds.
Research published earlier this year in the journal Nature Communications also suggested a link between global warming and more incendiary strikes – those that not only generate light and sound, but also trigger fires. By analyzing the history of lightning strikes in African savannas, this study found that lightning-caused fires were more severe during years with higher temperatures.
In certain weather conditions, an incendiary strike is more likely than a regular one because its core can reach a temperature of around 30,000 °C when clouds get too heavy, providing enough energy to start fires. Because cold temperatures and low air moisture helps to protect flammable objects from these fires, global warming has in some cases provided the right conditions for them to occur.
In addition to fires, incendiary lightning bolts can also cause other massive destructive wildfires that have already been seen in California, Portugal, Greece and Montenegro.
Climate change is already increasing the intensity of wildfires, but the world must now prepare for another risk posed by this unprecedented shift in weather patterns: incendiary lightning strikes. Implementing preventive measures, such as developing fire retardant materials in building and forest conservation plans is now essential.