Perilous
Times
Solar flare jams radio, satellite signals
* From: AFP
* February 17, 2011 8:26PM
A POWERFUL solar eruption that has already disturbed radio
communications in China could disrupt electrical power grids and
satellites used on Earth in the next days, NASA said.
The massive sunspot, which astronomers say is the size of Jupiter,
is the strongest solar flare in four years, NASA said yesterday.
The Class X flash - the largest such category - erupted on
Tuesday, according to the US space agency.
"X-class flares are the most powerful of all solar events that can
trigger radio blackouts and long-lasting radiation storms,"
disturbing telecommunications and electric grids, NASA said.
NASA's Solar Dynamics Observatory saw a large coronal mass
ejection (CME) associated with the flash that is blasting toward
Earth at about 900km per second, it said.
The charged plasma particles were expected to reach the planet's
orbit tonight.
The flare spread from Active Region 1158 in the sun's southern
hemisphere, which had so far lagged behind the northern hemisphere
in flash activity. It followed several smaller flares in recent
days.
"The calm before the storm," read a statement on the US National
Weather Service Space Weather Prediction Service.
"Three CMEs are enroute, all a part of the Radio Blackout events
on February 13, 14, and 15 (UTC). The last of the three seems to
be the fastest and may catch both of the forerunners about mid to
late ... February 17."
Geomagnetic storms usually last 24 to 48 hours, "but some may last
for many days", read a separate NWS statement.
"Ground to air, ship to shore, shortwave broadcast and amateur
radio are vulnerable to disruption during geomagnetic storms.
Navigation systems like GPS can also be adversely affected."
The China Meteorological Administration reported that the solar
flare had jammed shortwave radio communications in southern China.
It said the flare caused "sudden ionospheric disturbances" in the
atmosphere above China, and warned there was a high probability
that large solar flares would appear over the next three days, the
official Xinhua news agency reported.
In previous major disturbance of the Earth's electric grid from a
solar incident, in 1973, a magnetic storm caused by a solar
eruption plunged six million people into darkness in Canada's
eastern-central Quebec province.
The British Geological Survey said meanwhile that the solar storm
would result in spectacular Northern Lights displays.
One coronal mass ejection (CME) arrived on February 14, "sparking
Valentine's Day displays of the Northern Lights (aurora borealis)
further south than usual".
"Two CMEs are expected to arrive in the next 24-48 hours and
further... displays are possible some time over the next two
nights if skies are clear," it said.
The office published geomagnetic records dating back to the
Victorian era which it hopes will help in planning for future
storms.
"Life increasingly depends on technologies that didn't exist when
the magnetic recordings began," said Alan Thomson, BGS head of
geomagnetism.
"Studying the records will tell us what we have to plan and
prepare for to make sure systems can resist solar storms," he
said.