Two lightning records confirmed by the World Meteorological Organization last week sent shock waves to the entire scientific community and raised the bar for what to expect as surveillance technology improves.
The record was about length and duration. The length record was set on April 29, last year, with a megaflash that stretched 477 miles from Mississippi to Texas and across the northern tip of the Gulf of Mexico.
The duration record set on June 18th last year was a megaflash that lasted 17.1 seconds, just a moment ahead of the previous titleholder’s 16.7 seconds. It occurred in the La Plata basin in South America.
According to scientists, both occurred in lightning hotspots. Areas where megaflash events occur frequently and are very different in size from regular lightning bolts.
Their measurements are impressive, but more importantly, widespread and protracted storms like these indicate the potential dangers and dangers of megaflash storms. These flashes are not just a strike that hits one particular area, they can extend long distances and pose a serious danger to people even if they are not directly under lightning.
Randall S. Selveny, a professor of geography at Arizona State University and a reporter of extreme records at the United Nations World Meteorological Organization, said: .. “It really emphasizes the fact that lightning can hit far away from where it occurred.”
Scientists are still elucidating the cause of such megastorms, but they know that such a phenomenon occurs during convective thunderstorms, which are larger heat-based storms. This type of storm occurs frequently in Arizona during the summer monsoon, but Cerveny says meteorologists have never seen a megaflash of any of these sizes in the southwest. ..
Note that Cerveny and other experts state that these new records are not a sign of climate change, and that this type of storm may have been happening all the time. New is the technology used to monitor such weather events.
See the weather in a new light
Advances in technology have allowed scientists to see the weather in new light with finer particle details. Meteorologists have been used to study storms using location-specific techniques. Currently, they are using a combination of ground surveillance and a static lightning mapper. This is a geostationary environment satellite device that was first used in 2016.
Michael Peterson, an atmospheric scientist at the Los Alamos National Laboratory in New Mexico, said these devices provided greater knowledge of when and where megaflashes would occur. Unlike previous satellite and ground technologies that look at small geographic areas, GLM allows scientists to see storms from space across continents and regions.
Timothy Logan, director of the Houston Lightning Mapping Array Network at Texas A & M University, states that both methods have their strengths and weaknesses. Ground devices use radio waves to scan the air for currents throughout the region. Satellites allow scientists to actually look into clouds around the world.
In the case of radio, Logan said, “After a certain distance, the signal is lost, but it catches everything within the detection range.” “But geostationary satellite photodetectors need to look into the clouds, so the flash is bright enough to be detected.”
The flash of records along the Gulf was measured using the “maximum great circle distance method” to maintain consistency with past records. This approach calculates the distance between the two most distant points in the flash. Despite its length, Cerveny said it would be difficult to see.
“Many of the flashes were buried in a massive thunderstorm across the area. You wouldn’t have seen the first part of it all the way to the end,” he said. “And it’s been growing for so long, and it diverged to cover such a vast area, so you wouldn’t have been able to personally see the entire show there.”
Mega flash was also easy. At 8.55 seconds, it was a sudden burst of light that flashed quickly before it burned out. It was early in the day, so it would be difficult to see.
“A megaflash occurred around 9am CST,” Logan said. “The storm passed the Brian University station around 2 or 3 am. It awakened everyone. All weather geeks tweeted and provided information.”
Lightning safety issues
National Weather Service Nearly 50 people are reported to die from lightning strikes each year in the United States. Notable extreme examples of WMOs are a single lightning strike that killed 21 people in Zimbabwe in 1975, and an indirect lightning strike that killed 469 people when a lightning strike on an oil tanker in Egypt caused a flame. Swallow the town in 1994.
However, Tucson meteorologist Ron Hore, who worked for the US National Oceanic and Atmospheric Administration, says the number in the United States is above the 30-year average. Advances in technology, education, structure, and medical care have reduced that number. Last year, there were only 13 lightning-related deaths in the United States, according to Hore.
Human lightning strikes include direct hits, side flashes, telluric currents, contact voltages as current surges travel along wires and metal surfaces, and upward leaders that appear within 0.5 miles of the original lightning strike. There are 5 types.
“Maybe you’re thinking that lightning will come down from above and hit your head. It rarely happens. It’s probably a 3-5% chance,” Holle said. “The most common is the flow of the ground where it hits near the open field and moves across the ground. It’s probably 30-40% of the time.”
Previous record:A 440-mile long lightning bolt? ASU scientists verify flash
Experts like Holle warn that if someone is hit by a thunderstorm, the thunderstorm can travel very fast and long distances. The only real safe place is a building or structure with plumbing and wiring. This allows lightning to find an easy route to the ground. If a structure with such infrastructure is not available, a closed top car is recommended as lightning is likely to move around the vehicle without passing through it.
Scientists expect more records to be documented as surveillance efforts improve and more countries expand their technology. Efforts are already underway in Europe and Asia to deploy similar GLM-type satellites.
“In addition to our satellites, we have an international partner in lightning science who is launching a GLM-like device to see other parts of the Earth, or launching a similar device,” Peterson said. Says. “Because lightning is a global phenomenon, getting this expanded coverage is really exciting.”
Environmental coverage at azcentral.com and The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow the Republic Environmental Reporting team on Facebook, Twitter, Instagram environment.azcentral.com and @azcenvironment.
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