Passive electrical measurements from three Oklahoma tornados

Passive electrical measurement of three tornados in the Oklahoma area have been made and are being reported upon. The measurements made include point discharge current, 18.5-kc/s sferics, along with 10-, 50-, 100-, and 175-kc/s, and 30-Mc/s sferics. The preceding measurements of tornados are compared with a typical local thunderstorm. In this comparison, it is shown that the electrical discharges within the tornados are much more intense than in local thunderstorms, particularly in frequency of occurrence. Data also show that the normal frequency spectrum of sferics radiation is different from the frequency spectrum of the tornados measured. Furthermore, the tornado sferics appear to have a definite aperiodic structure that may be present to a limited extent in the intense portion of a thunderstorm. Similarities between the measurements made on the Oklahoma tornados and Jones's work are pointed out. Finally, it is suggested that a coupling between the electrical and mechanical energies of the tornado may be responsible for the difference noted between tornado sferics and thunderstorm sferics.