Massive solar storm detected as concerns turn to Earth's systems
The US weather service has warned of an unusually intense solar flare
which could disrupt satellites and electricity grids. Deutsche Welle
takes a look at what a solar storm is and the damage it can do.
It was expected that satellite navigation devices and radios
would experience waves of interference on Wednesday, the US National
Weather Service (NWS) said, as a massive solar flare erupted on the sun.
The solar storm was also expected to affect power supplies and could
cause malfunctions in other electrical systems. Furthermore, flights
through polar regions may need to be diverted, the NWS warned.
The so-called Coronal Mass Ejection is a huge burst of solar wind and
magnetic fields from the sun which are released into space. Klaus
Börger from the Geo Information Service with Germany's armed forces, the
Bundeswehr, said such eruptions can develop from sunspots which are
visible from Earth.
US space agency NASA said it observed the recent solar activity from
12 unmanned satellite observatories and spacecraft using a specialized
telescope for measuring radiation which was installed in a lunar probe
and launched in 2009.
 Satellites are particularly affected by solar storms
Nuclear fusion reactor
The sun has a diameter of just under 1,400,000 kilometers (roughly
865,000 miles) with an internal temperature of several thousand degrees
Celsius. This heat is produced by nuclear fusion which creates millions
of tons of hydrogen and helium by the second. These nuclear reactions
lead to observable explosions.
Recent days have seen several small outbreaks, culminating in three
different types of radiation exposure. Immediately following an
explosion, a flash of light sparks out from the sun, taking little over
eight minutes to travel the 150 million kilometers to Earth. Around 30
minutes later, charged particles loaded with a voltage in the billions
begin striking the Earth's atmosphere. Next comes the actual geomagnetic
storm, which consists of particles racing toward the Earth at roughly
900 km/s. They need up to 46 hours to reach our planet.
NASA scientists have classified the current eruption as major and
warned it could lead to ongoing radiation storms. The NWS, meanwhile,
said it anticipated the effects of the storm would be "low to moderate,"
given Earth was not directly in the path of the eruption.
According to NASA, this is the most violent solar storm since 2006.
The most powerful solar event on record occurred in 1859. Experts warn
that if a similar "super eruption" were to take place today it could
knock out infrastructure across large swathes of the world.
 Scientists have been studying Coronal Mass Ejections for decades
Electromagnetic influence
Solar storms are considered a threat to key infrastructure due to our
dependency on technology such as satellites, which are particularly
sensitive to changes in surrounding electromagnetic fields.
Satellite-controlled GPS navigation systems are now an indispensible
element of the logistics sector, as well as important for the maritime
and aviation industries. They are particularly vulnerable to solar
activity.
Satellites send their electromagnetic signals from around 20,000 km
above Earth, said Klaus Börger: "At an altitude of between 1,000 and 50
km [the signals] then travel through the ionosphere, and this influences
the direction and speed of the signal."
GPS receivers determine their position from signals obtained from at
least four satellites. "The signal travel time is multiplied with the
speed of light to calculate the distance to the satellite," said Börger.
However, distortions to the electromagnetic field in the ionosphere
can change the signal travel time. "This can mean GPS failures depending
on dramatic deviations in the ionosphere," Börger said.
Electrical systems are also heavily impacted by solar radiation, as
evidenced nearly 40 years ago, long before the Internet and GPS age. In
1973, a solar flare caused a blackout in the Canadian province of
Quebec, leaving six million people sitting in the dark. The power
interruption was caused by a deformation of the Earth's magnetic field
by incoming charged particles.
 The aurora borealis lights are visible in the northern reaches of the world
Magnetic fields generated through solar storms which correspond with
electrical fields and currents on Earth can also have other effects,
said Börger, including even burning out transformer substations.
Eleven-year itch
NASA scientists already know that solar activity follows certain
cycles which reach a high point approximately every 11 years. The next
apex is expected to come around in 2013. During periods of high sunspot
activity, people with shortwave radios will be able to detect reception
disruptions.
Earth's magnetic field protects us from cosmic radiation carried by
incoming particles in the event of such solar high points. A side effect
of this can be seen at the Earth's poles in the aurora borealis and
australis, or northern and southern lights. The colorful lights in the
sky are caused by the collision of charged particles caused by a solar
wind and directed by the Earth's magnetic field.
Author: Fabian Schmidt (AFP, AP) / dfm
Editor: Nicole Goebel
http://www.dw-world.de/dw/article/0,,15142365,00.html
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