EARLY-WARNING SYSTEM FOR SOLAR STORMS IN WORKS.

Byline: Jane E. Allen Associated Press 

Scientists think they're close to providing 50 to 70 hours of warning before huge solar storms knock out telecommunications and electronics systems here on Earth.

The key is picking up signs of the storms as they're occurring on the sun, 93 million miles away.

Observations by the $19 million Soft X-ray Telescope aboard the U.S.-Japanese Yohkoh satellite helped scientists link a dimming of the sun's corona with huge solar flares that stream to Earth and disrupt power and satellite communications.

"We've made the connection," said Hugh Hudson, a University of Hawaii astronomer. He predicted that within a couple of years, another X-ray telescope belonging to the National Oceanic and Atmospheric Administration could be offering daily solar weather reports.

Hudson was among three experts who presented findings Thursday during a solar storm conference sponsored by the American Geophysical Union and the National Science Foundation. The international gathering at NASA's Jet Propulsion Laboratory in Pasadena included solar physicists, power and utility representatives and participants from the Department of Energy's national laboratories.

In an advance interview, Hudson said scientists found that at the same time there's a flare near the Sun's surface, its corona disappears and spits out about a billion tons of gas.

The solar gas takes 50 to 70 hours to reach the Earth, where it interacts with the Van Allen radiation belt, a perpetual cloud of high-energy particles that surrounds the equator like a doughnut.

The flow of solar particles creates electrical currents that alter the Earth's magnetic field. That leads to power surges that can blow up transformers and shut down circuit breakers.

By detecting the solar flare as it begins, scientists could provide more than two days' notice that a disruptive magnetic storm might be on the way.

In another significant finding, Douglas Hamilton, an associate physics professor at the University of Maryland, found that at the beginning of these large magnetic storms on Earth, charged oxygen atoms are being drawn out of the upper reaches of Earth's atmosphere and into the Van Allen Belt.

"We now know from directly measuring the change in the radiation belt that . . . an additional 10 to 20 tons of oxygen is added to the Van Allen Belt in a great storm," Hamilton said.

He said the practical value of understanding how the storms work is to help prepare for the terrestrial consequences.

John Kappenman, an electrical engineer for Minnesota Power, noted that a March 1989 magnetic storm created a blackout for 6 million people in Quebec and "very nearly cascaded into a major part of the Eastern United States."

The storms can have effects from coast to coast.

For example, an October 1991 magnetic storm affected power plants in the Chesapeake Bay, Illinois, Wisconsin, Texas, Mexico and the Pacific Northwest, he said.

And the economic consequences can be huge. The Department of Energy recently estimated a large magnetic storm could have a $3 billion to $6 billion economic impact.

The space sensing now being developed "will give us some advance warning of the severity and regions of the globe that will be impacted," Kappenman said.