Dwyer and researchers from Florida Tech's Department of Physics and Space Sciences and the University of Florida's International Center for Lightning Research and Testing are the first to use X-ray detectors and rocket-triggered lightning to study nature's light show. They discovered that lightning flickers in X-rays just as it does in visible light, but 10,000 times faster. Their research is published in this month's issue of Geophysical Research Letters.
"This is remarkable when you consider that a couple years ago, no one knew that X-rays were even emitted during lightning strikes," said Dwyer.
"Now we're actually looking at lightning with X-rays, which allows us to see it in a brand new way."
In the study, X-rays were produced in bright bursts about one-millionth of a second apart. As a reference, one could imagine that, viewed in X-rays, a lightning strike would look like a series of flashes descending from the cloud much like the flashbulbs popping around the stadium during a Super Bowl kickoff. Further surprising to the scientists are the X-rays' energies.
"When we measured the energies of the X-rays, we found that they extended up to about twice the energy typically found in a chest X-ray," said Dwyer.
Scientists will continue to study the source of the X-rays, and what the effects are in both the atmosphere and to anyone on the ground near a strike.
"We are learning that many of our old ideas about lightning were wrong, and that's what makes this work so exciting," Dwyer said.
Journal
Geophysical Research Letters