This week's second series of major solar flares is producing geomagnetic storms that could threaten satellites, power grids and communications networks, a federal agency says.
The National Oceanic and Atmospheric Administration (NOAA), a unit of the U.S. Department of Commerce, reported that the sun continues to produce the flares, technically known as coronal mass ejections, with a "spectacular" example that occured Tuesday. The NOAA identified a similar event last week.
Researchers at the NOAA's Space Environment Center in Boulder, Colo., said the latest flare produced a radiation event that rated an S3, or strong, designation on the NOAA's five-level space weather scales. The incident also caused an R4, or severe, radio blackout. NOAA forecasters expect the rapidly advancing discharge from the sun to reach the Earth's magnetic field on Wednesday at about midday, producing a serious geomagnetic storm that's expected to continue the next few days at varying levels of intensity.
According to at least one communications industry expert, most solar flares pose no major threat to satellites and other technologies, but an event as large as the one currently unfolding always has the potential to create problems. Joe Laszlo, an analyst at Jupiter Research, pointed to a similar storm that shorted out components on a satellite PanAmSat operated in May 1998, causing problems for several major paging companies.
Satellite operators tend to have plenty of warning regarding these situations, since the flares are seen long before related particle storms arrive, and most put their satellites in safe mode or turn off unnecessary operations as a safeguard, said Laszlo. However, as the 1998 incident highlighted, there is always the possibility of trouble.
"There's no example of cell phone networks being affected, but power systems have been shut down in the past," said Laszlo. "People aren't very conscious of all the systems that depend on satellites to work."
Laszlo drew attention to the fact that television signals and banks' ATMs (automatic teller machines) are often linked to satellite-oriented technologies.
The NOAA warned that an S3 flare like Tuesday's can result in a number of satellite issues, including noise in imaging systems and reductions in solar panel efficiency. Many satellites rely at least partially on solar power for operation. In addition, the resulting geomagnetic storms could compromise satellite and low-frequency radio navigation systems and cause surface changes on satellite components that increase drag on low-Earth-orbit spacecrafts. Some satellites may also experience orientation problems.
Other potential effects included possible interference with high-frequency radios, which could affect some of the world's wireless communications networks. The storms could also trigger false alarms in protection devices that are built into some of the planet's power systems. Any radio blackout would most likely affect the sunlit side of the Earth, the NOAA said.
NOAA forecaster Bill Murtagh said the most recent flare appears to be the second largest during this solar cycle, each of which tends to last about 11 years. Murtagh compared the event to a similar flare and geomagnetic storm that occurred in July 2000 and was dubbed the Bastille Day storm, since it materialized on France's national holiday. That storm produced considerable disruption to both ground- and space-based high-tech systems.
The probability of another major flare occurring is high, NOAA forecasters said, and additional geomagnetic and radiation storms are likely. The storms do not directly affect humans, since the Earth's atmosphere deflects most of the harmful radiation particles, but the NOAA cautioned that people in commercial jets at high latitudes may receive low-level exposure. That radiation would be equivalent to the same amount of heat a typical chest X-ray generates. On a more positive note, the aurora borealis, or northern lights, may be visible in the northern tier of the United States as a result of the flares.