The frequency of lightning bursts as well as the altitude at which they occur can be an indicator of a storm's strength.
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A sensor network originally designed to detect nuclear blasts is now giving the most detailed look ever into the inner workings of hurricanes.
The network builds on recent research, which has shown that lightning activity fluctuates along with the intensity of tropical storms and hurricanes. Properly understood, this finding could spark a revolution in forecasting the often erratic behavior of these dangerous storms.
National and global lightning detection networks are limited in their ability to pinpoint the location of individual lightning bolts within a few miles. However, this new array of lightning detectors lining the coast of the Gulf of Mexico aims to change all that.
Eighteen low and high-frequency detectors make up the Los Alamos Dual-Band Lightning Mapping Array. The network uses multiple listening stations to zero in on every flash of lightning, providing instantaneous information on each bolt's exact location, including its altitude inside a cloud.
As clouds build, lightning bolts will crack ever higher in the sky, a tell-tale sign that a storm is strengthening.
"As a storm moves over a warm patch of water, it revs up convection, which causes a burst of lightning activity," Christopher Jeffery of Los Alamos National Laboratory in New Mexico said. "With really high-resolution data, we're able to see that convective event."
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Bursts of lightning cannot occur without just the right balance of supercooled water droplets and ice crystals inside a cloud. Strong updrafts with speeds up to 30 meters per second (67 miles per hour) chill the water, which soon freezes. Without constant convection bringing in new liquid water, hurricanes can glaciate, or weaken, when all of the water turns to ice crystals.
In other words, the frequency of lightning bursts as well as the altitude at which they occur can be an indicator of a storm's strength.
"We're trying to understand the basic fundamental processes, the physics of a storm," Jeffery said. With that knowledge, he hopes to build improved forecasts of hurricanes that will increase warning times, and ultimately save lives.
"In the past, people thought that there wasn't a lot of vertical convection in hurricanes, because hurricanes actually get stronger based on their horizontal winds," Natalia Solorzano of Bard High School Early College said.
However, the strong connection between lightning and changes in storm intensity, which she previously observed in her own research, shows that lightning is in fact a good predictor of hurricane behavior.
Tags: Hurricanes, Lightning, Storms
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