A team of scientists from the Southwest Research Institute have successfully imaged thunder for the first time by artificially triggering lightning, they reported at a meeting between American and Canadian geophysical societies in Montreal.
Because thunder and lightning are unpredictable, the phenomena are best studied using triggered events. The technique involves launching a small rocket trailing a grounded copper wire into thunderclouds.
The copper wire provides a conductive channel and creates a predictable path for lightning, allowing scientists to precisely focus their instruments and perform repeatable experiments close to the discharge channel. Using SwRI internal research funding, Dr. Maher Dayeh led a proof-of-concept experiment to image the acoustic signature of thunder.
SwRI conducted experiments at the International Center for Lightning Research and Testing at the University of Florida, Gainesville, taking advantage of the state’s claim to the most lightning strikes per year in the U.S.
SwRI scientists compared long-exposure optical photographs of two different triggered lightning events (on top) with acoustically imaged profiles of the discharge channel (below).