A Japanese government institute has warned that satellite transmissions, GPS readings, and power lines could be affected over the next two weeks if a recent spate of solar flares continues.
Four large solar flares have been detected over the last few days, including one on Tuesday that was the largest of the year. The flares were judged to be "X-class" by NASA and other agencies, the highest in a linear scale based on X-ray measurements.
Japan's National Institute of Information and Communications Technology, or NICT, said the flares came from a group of sunspots that are pointed away from the Earth, but are due to rotate to face in the Earth's direction over the next week. NICT said that if more major flares occur during that time, there could be problems for satellites and other equipment.
"There is a danger that man-made satellites such as communications and broadcast satellites could be impaired, errors in high-precision GPS measurements could increase, short wave transmissions could impaired, and power lines could be affected by sudden geomagnetic changes," the institute said in a press release in Japanese.
Data from NASA and NICT show that the largest of the flares was rated X3.2, the largest of the year so far. NASA said on Tuesday that the flares had emitted a coronal mass ejection that could affect some satellites. Such ejections include plasma and electromagnetic radiation.
Governments have warned that 2013 could see a peak in solar flares, activity which follows a roughly 11-year cycle. The last maximum in activity came in 2000.
X-rays from solar flares are stopped by the atmosphere, but can affect satellites that orbit the Earth and GPS measurements. Coronal Mass Ejections can also affect satellites, and can trigger geomagnetic storms that cause high currents in power lines, damaging transformers and power stations. They take from three to five days to reach the Earth, according to NASA.