Reported August 2008

ABOUT TORNADOES: A tornado begins with a thunderstorm cloud, which can build up a lot of energy. If this energy creates a particularly strong updraft of air, it will form a vortex, much like how a whirlpool forms in a draining bathtub. The air is pulled toward the center in a spiral, forming a tornado under the thundercloud. Wind speeds can reach 200 to 300 MPH, and if the dangling vortex touches ground, the combination of the whirling wind's speed, the updraft, and pressure differences can cause severe damage. The path of a tornado is determined by the path of the parent thundercloud, but it will often appear to hop (called a "jumper"). This occurs when the vortex is disturbed, causing it to collapse momentarily and reform.

GRAVITY WAVES: : Gravitational waves are "ripples" in the curvature of space and time, made by the motion of matter, much like a pebble tossed into a pond will cause waves to ripple outward from the source. But gravity's "waves" are not traveling through space-time, like light or sound waves; rather, it is space-time itself that is rippling up and down. A number of events could trigger the formation of gravity waves in the atmosphere, from wind shear to the updraft caused by a thunderstorm, or an abrupt change in the jet stream. Gravity waves spread out from these disturbances like the ripples in a pond. A gravity wave that encounters a thunderstorm will compress it, causing it to spin faster. When storm rotation increases, the storm becomes more powerful and more likely to produce a tornado.

The American Geophysical Union, the American Meteorological Society, and the American Physical Society contributed to the information contained in the TV portion of this report.

If you would like more information, please contact:

Timothy A. Coleman, Research Associate, Atmospheric Science Department
The University of Alabama in Huntsville
(205) 612-4229
coleman@nsstc.uah.edu

American Geophysical Union
(800) 966-2481
http://www.agu.org

American Meteorological Society
(617) 227-2425
http://www.ametsoc.org

James Riordon, Media Relations
American Physical Society
(301) 209-3238
http://www.aps.org
Riordon@aps.org

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