Recent solar activity has proven a previously unrealized weakness of Global Positioning System (GPS) technology, scientists warned last week during the first Space Weather Enterprise Forum, held in Washington, D.C..

The National Oceanic and Atmospheric Administration (NOAA) disclosed findings detailing how an unprecedented solar eruption in December led Cornell University researchers to confirm that solar radio bursts can seriously impact the GPS and other communication technologies using radio waves.

As NOAA explained, solar radio bursts begin with a solar flare’s injecting high-energy electrons into the solar upper atmosphere. Radio waves are produced, propagating to the Earth and covering a broad frequency range. The radio waves act as noise over affected frequencies, and can thus degrade a signal from GPS and other navigational systems depending on such.

Forecasters from the NOAA Space Environment Center in Boulder, Colo., reportedly observed two powerful solar flares on Dec. 5 and 6 originating from a large sunspot cluster identified by NOAA.

On Dec. 6, a solar flare created an unprecedented intense solar radio burst, causing large numbers of receivers to stop tracking the GPS signal. Using specially designed receivers built at Cornell as sensitive space weather monitors, scientists measured the effect of earlier solar radio bursts on GPS receivers and noted that larger solar radio bursts, expected during solar maximum, would disturb some GPS receiver operation, perhaps "enough to swamp GPS receivers over the entire [daylight] side of Earth," according to Cornell’s Paul Kintner, professor of electrical and computer engineering.

"In December, we found the effect on GPS receivers were more profound and widespread than we expected," Kintner said. "Now we are concerned more severe consequences will occur during the next solar maximum."

The solar maximum occurs roughly every 11 years, when changes in Earth’s closest star’s magnetic field bring about an increase of sunspots, solar flares and events called coronal mass ejections. The result is Earth’s being bombarded with an array of charged particles to varying degrees of affect.

"This solar radio burst occurred during the solar minimum, yet produced as much as 10 times more radio noise than the previous record," said Dale Gary, physics department chairman and professor at the New Jersey Institute of Technology (NJIT).

He added "measurements with NJIT’s solar radiotelescope confirmed, at its peak, [that] the burst produced 20,000 times more radio emission than the entire rest of the sun."

After the December 6 episode, researchers at Boston College noted that it was the first time a solar radio burst was detected on Wide Area Augmentation System (WAAS), the civil air navigation system.

NOAA, NASA and partner agencies in the National Space Weather Program are collectively considering the future and ever-increasing technical needs of modern society, and are anticipating seamless specification and a predictive forecast of the atmosphere from the ground to the edges of the Earth’s magnetosphere and beyond, to the Moon and Mars.

The NOAA Space Environment Center is charged as the nation’s first alert for such solar activity.

The Global GPS Network, a set of precise GPS receivers used for a variety of scientific and real-time applications, also was affected by the recent solar disturbance. Its applications include a very high accuracy positioning service that can provide a user’s position to within 10 to 20 centimeters’ accuracy anywhere in the world, be it on land, in the air or in Earth’s orbit.

There are three key points to remember about solar radio bursts, warned Anthea Coster of the Massachusetts Institute of Technology’s (MIT) Haystack Observatory.

"First," she enumerated, "society cannot become overly reliant on technology without an awareness and understanding of the effects of future space weather disruptions."

Coster added "second, the December 6 event dramatically shows [that] the effect of solar radio bursts is global and instantaneous."

And, she concluded, "third – and equally important – the size and timing of this burst were completely unexpected and the largest ever detected. We do not know how often we can expect solar radio bursts of this size or even larger."