Citation

Brook M. Science 1967; 157(3795): 1434-1436.

Copyright

(Copyright © 1967, American Association for the Advancement of Science)

DOI

10.1126/science.157.3795.1434

PMID

17819546

Abstract

Measurements of the magnetic field and earth current in the vicinity of a tornado show large steplike deflections coincident with the touching down of the funnel. Calculations with a simple current model indicate that a minimum current of several hundred amperes must be postulated to account for the observed deflection in magnetic field. The existence of a steady current of 225 amperes for a period of about 10 minutes provides joule heat at the rate of approximately 10(10) joules per second, and involves a total charge transfer of 135,000 coulombs. The calculations imply that a tornado is electrically equivalent to several hundred isolated thunderstorm cells active simultaneously.

Language: en