SAN FRANCISCO — Until now, most people have associated blackouts, brownouts, and telephones on the blink with foul weather here on Earth - seasonal hurricanes or a nasty blizzard.
But the more scientists know about solar outbursts and magnetic space storms, the more concerned they are that our expanding electrical grids and communication and navigation satellites are at the mercy of weather in outer space.
Scientists say new research unveiled at a meeting here of the American Geophysical Union shows that not just the sun, but Earth itself is spewing charged particles into the atmosphere. The discovery is expected to produce better forecasting and give executives of utilities and communications companies more time to prepare for stormy space weather.
It's a situation, the scientists say, where new knowledge can balance the risk of a significant new hazard.
Richard Behnke, who heads the National Science Foundation's Upper Atmospheric Research Foundation, says "we're becoming more and more vulnerable to the space environment" because solar activity will be moving into the maximum phase of its 11-year cycle over the next five years.
He likens the situation to living in high-rise condos along a coast prone to hurricane attack. But unlike the condo dwellers, satellite and power company managers don't have to cut and run when space weather turns threatening.
Given adequate warning, they can take evasive action. Satellite managers can turn off vulnerable circuits and use alternative systems less likely to be affected by a particular space storm.
Power companies can prepare their distribution systems to cope with expected current surges induced by magnetic storms.
Space forecasters generally can give only a few hours warning now. Dr. Behnke compares this with conventional weather forecasting 50 years ago. Since then, computer-based forecasting has extended the outlook to several days. Behnke expects space weather forecasting to make similar progress in the next decade.
Scientists working in this field echo that expectation as they reported their latest findings in several technical sessions and press conferences here.
Mario Acuna of the Goddard Space Flight Center in Greenbelt, Md., says that for the first time scientists have "a critical mass" of research satellites. This international flotilla can monitor closely what's happening on the sun, in space surrounding Earth, and in the space controlled by Earth's magnetism, an area called the magnetosphere.
Coupled with ground-based measurements, this new research capability is rapidly building the knowledge needed to improve space weather forecasting.
Scientists briefing the press emphasized two key findings that illustrated this development. Both were made by a US satellite, Polar, that patrols space along an orbit that loops over the North and South Poles.
Dr. Acuna explained that "the holy grail of space physics" has been to observe a process called magnetic field recombination. It's a fundamental process of energy transformation by which magnetic fields in space pump energy into Earth's space weather system. Scientists have theorized about this for decades.
Last May, Polar moved into a region where this long-sought process was actually going on, finally allowing researchers to test their theories against the data.
Observations with Polar have produced a second key finding showing that some of the particles that cause magnetic substorms in the magnetosphere and give rise to aurora come from Earth itself.
Thomas Moore of The Marshall Space Flight Center in Huntsville, Ala., says he and his colleagues used a new instrument able to detect previously invisible low-energy particles and found them streaming up out of Earth's outer atmosphere.
To help ensure that society makes the most of this new knowledge to cope with space weather, several US government agencies, including the National Science Foundation, are working to coordinate research and develop better forecasting.
Behnke calls it "a real nice blend of research and its application in service to society."