Washington, DC —The Fourth of July celebration in Washington, DC, aimed at a record this year for the largest fireworks display in history, with organizers setting up 850,000 shells and other pyrotechnics. But nature showed up to compete for attention. Lightning started striking about midway through the show, with bolts darting vertically and from cloud to cloud and eliciting bigger reactions than the human-made display got, at least from the crowd gathered on the south side of DC’s Washington National Cathedral.
Lightning repeatedly struck over the National Mall in Washington, DC, during the Fourth of July fireworks, as seen here from the National Cathedral. Credit:
Colin Winterbottom
C&EN was on the scene, and the lightning darting through the fireworks smoke made us wonder, did all the particulates and metal ions churning above the city cause or intensify the electrical storm? Luckily, the magazine has written about lightning a few times recently, so we had some experts on speed dial.
“Interesting question. I would doubt that the fireworks had anything to do with the lightning but cannot rule out the possibility,” says Martin Uman, author of the book All About Lightning and a retired electrical engineering professor at the University of Florida. “Summer lightning generally initiates in precipitation at an altitude near or above 15,000 feet; the fireworks are much lower than that.” However, he said, smoke rising into the clouds above the city could have seeded in-cloud precipitation, which is related to cloud charging and then lightning initiation.
But probably, it was just fortunate timing, Uman says. “Too many things would have to line up just right.”
Credit: AP Photo/Allison Robbert (monument); Colin Winterbottom (gargoyle)
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