Scientists launched the project to see how well they could track lightning from space--but they got a surprise! The satellite picked up a lot more lightning than our ground-based lightning tracking system. It also seems to have picked up the development of a tornado!

The image at the left shows how well the satellite picks up lightning. A tornado occurred near the most intense bunch of flashes. This data is from April 17, 1995, when the OTD satellite passed above a storm in Oklahoma and "saw" about 200 lightning flashes. During the same period, only nine flashes were seen by the Earth-based sensors.

Just after the satellite detected a peak in the cloud-to-cloud lightning, a twister touched down. The results were very promising and NASA researchers are currently following up on the results. The research seems to show that cloud-to-cloud flashes get most intense just before a twister touches down.

Electric Clouds
The researchers had thought we might be able to see more lightning from space, but were surprised at how much the ground systems can't see. The detector found that much more lightning flies between clouds (cloud-to-cloud) than between clouds and Earth. NASA investigator Hugh Christian says, "In some cases, there are up to 20 times more lightning flashes within clouds than is observed by the ground-based network" of lightning detectors.

They were also excited to see how lightning related to the tornado touchdown. "The intensity of the lightning (flash rate) seems to be related to storm intensification," Christian says. "The formation of a down draft causes a decrease in flash rate and may help lead to tornado formation."

Researchers plan to keep looking into how OTD satellites might help us warn people about developing tornadoes. Even with the new technology, however, the results won't be perfect. It's not likely that all tornadoes show this distinctive pattern of lightning.

NASA Researchers have applied to send another OTD aloft, Christian says, in an orbit with a broader field of view that would allow nationwide now-casting of tornadoes. If everything goes smoothly, the launch could occur in 2000.

So tornadoes are in the wind. How can I protect myself?

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This lesson created by "The Why Files," a NISE project funded by the NSF. Lesson used by permission. Original lesson and graphics copyright NISE. Modifications copyright BPNM.