Duke University engineers are seeking to understand why some thunderstorms in tropical regions seem to generate gamma rays along with lightning bolts.
Gamma rays are a powerful form of radiation typically associated with violent events in outer space. But two different satellites have detected them in earth's atmosphere, concentrated in areas of Africa, Indonesia and the Caribbean. Researchers have determined the gamma ray bursts are being emitted just ahead of lightning strokes in tropical thunderstorms.
Steven Cummer, an assistant professor at Duke's Pratt School of Engineering, used radio wave detectors at a research site near campus to do the most detailed analysis of links between satellite-detected gamma rays and lightning discharges in Caribbean storms.
Cummer found that each gamma outburst seems to precede its associated lightning discharge by only milliseconds. His analysis also unexpectedly showed that these gamma rays originate relatively low in thunderclouds and associated lightning strokes are relatively weak.
To learn more about Cummer's findings, read the news release, "Gamma Rays from Thunderstorms?" and watch the brief accompanying video.