Storm
Warnings
for the
Sun
Earth. (NASA)
By Paul Recer
The Associated Press
W A S H I N G T O N, Nov. 10 ? The sun will greet the
new millennium by turning angry, erupting into
the most active part of its 11-year cycle with
outbursts of energy that can threaten satellites,
electrical power and spacewalking astronauts.
Officials at the National Oceanic and Atmospheric
Administration said today the approaching solar storm
could be more destructive than previous cycles because the
Earth has more power grids and satellites that might be
affected.
?There are bigger power grids, drawing more power
now so the power companies are more vulnerable,? said D.
James Baker, the NOAA administrator.
There are also 600 satellites, more than ever in history,
that also might be affected, said Baker.
This year, though, the power companies and satellite
operators will be better prepared than ever, he said.
Warning Satellites on Watch
Two satellites, operated by NOAA, NASA and the Air
Force, are positioned in orbit to warn about hazardous
energy bursts from the sun.
One satellite, orbiting a million miles from Earth, will
detect a rise in charged solar particles and give an hour?s
warning.
Baker said that will be enough time for power
companies to protect their electrical grids.
Satellite operators can protect orbiting equipment by
turning off circuits to prevent shorts, by closing solar panels,
or by turning away from the wave of energy. He said
operators are also prepared for ?ghost signals,? spurious
electronic surges that may prompt the satellite to take an
unexpected action.
Head Start for Astronauts
The hour?s warning also would allow spacewalking
astronauts to seek the safety of the shuttle or the space
station.
Baker said that NOAA also has created a new scale to
precisely describe the intensity of solar storms. He said the
new values ?are the Richter scales of space weather.?
The scales will predict the intensity of three types of
energy eruptions from the sun: geomagnetic, radiation and
radio storms.
For geomagnetic storms, caused by ejections of
charged masses from the corona of the sun, there is a scale
of G1 to G5. The strongest, G5, warns of electromagnetic
energy powerful enough to knock out power grids, disable
satellites and cause auroras, the so-called northern lights, to
be visible as far south as the equator.
From Mild to Wild
For radiation storms, caused by bursts of protons and
neutrons, the scale is from S5, the strongest, to S1. An S5
storm would be powerful enough to kill spacewalking
astronauts, disrupt communications, cause memory losses
in satellites and even disrupt navigation signals.
For radio storms, caused by bursts of radio frequency
energy from the sun, the scale is from R5, the strongest, to
R1. An R5 storm could cause a blackout of high frequency
radio signals on the sunlit side of the Earth and disrupt low
frequency navigation signals for hours.
The sun goes through an 11-year cycle, building up
energy outbursts until it reaches what is called solar max.
Baker said the solar activity is building now and should
peak next year and then tail off.
During the last solar max, in 1989, a major geomagnetic
storm sent a power surge through electrical lines, burning
out switches and transformers and causing an extended
blackout in Quebec. The same storm also knocked out
some Defense Department satellites, said Baker.
Pager Outage Shows Effects
A solar storm last year was blamed for the loss of a
communications satellite that put 40 million pagers and
phones out of business, Baker said.
He said the approaching solar max should be only
?average,? about like the one in 1989. But this time, he
said, most power companies and satellite operators are
ready.
?They are better prepared now,? said Baker. ?If they
get a warning, they are ready to act. An hour?s warning is
enough for the power guys.?
The companies can reroute and reduce power, even go
to a partial brown out to absorb any surge of energy from
the sun, he said. |
