Record Solar Outburst recorded

Dale Gary, Solar Physicist. Credit: New Jersey Institute of Technology

"The odd thing about this outburst was that the Sun is supposed to be at the minimum phase of its 11-year cycle," said Gary. "Nevertheless, the disruption lasted more than an hour, produced a record amount of radio noise, and caused massive disruptions of Global Positioning Satellite (GPS) receivers world wide."

Since 1997, Gary has directed Owens Valley Solar Array (OVSA), one of the world's leading research facilities to study the sun's impact upon earth. Using special instruments, Gary and researchers at NJIT's Center for Solar-Terrestial Research study solar outbursts. The National Science Foundation and NASA support the work.

A complex sunspot on the Sun was responsible for the outburst, which occurred Dec. 6, 2006 at 3:45 p.m. EST, said Gary. Before the outburst, the radio output of the Sun in the GPS broadcasting band was 54 on the scale of solar flux units. During the outburst, associated with a large solar flare, the radio noise reached around 1 million solar flux units, according OVSA instruments.

"This reading is more than 10 times the previous record, and calls into question scientists' assumptions of the extent to which the Sun can interfere with GPS and wireless communications," Gary said. "OVSA's results are especially useful because they monitor the same right-hand circular polarization that the GPS satellites use for broad-casts. Most other radio instruments measure total intensity rather than circular polarization, which undercounts the noise effect on GPS signals."