Scientists who chase dust devils report that the tiny twisters can produce a small magnetic field that changes magnitude between 3 and 30 times per second.
When grains of sand and clay collide inside a dust devil, they generate electric charges, says William M. Farrell, a geophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Md. Negative charges typically transfer to the smaller, lighter particles, which are lofted higher than the heavier grains.
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