Basic HTML Version
touchline
12
Feature
Space weather and solar storms may not feature highly on your list of pressing concerns in the current financial climate,
but the prospect of magnetic storms and solar flares pose a very real risk for businesses in the near future.
Space weather activity has been at its lowest for nearly 100 years between 2006 and 2010, and there is historical evidence
to suggest that severe events have been unusually rare over the past 50 years. For these reasons, space weather
has perhaps gone unnoticed or overlooked. However the emergence in recent years of vulnerable technologies and
an increased ‘creeping dependency’ on interconnected electronic systems has magnified the effects and places space
weather as a credible socio-economic threat.
The three main areas that may be affected are transport, aviation and power sectors but what is space weather, and what
causes it?
Solar activity passes through cycles of 11 years, the next of which commences in 2012. During these cycles activity
reaches ‘maximum’ and ‘minimum’ periods. It is during these ‘maximums’ that the Sun’s activity is more intense, and the
next maximum is due between 2012 and 2015. During the maximum of 1989, a huge magnetic storm caused the Hydro-
Quebec power grid to shutdown within 90 seconds, leaving six million people without power for nine hours and an
estimated cost of C$2bn.
The Sun’s activity is measured by counting sun spots – these are cooler zones of the surface (between
roughly 3,250-4,750 degrees Celsius as opposed to the usual 6,000). It is increased magnetic
activity that inhibits convection currents in these areas resulting in cooler, dark spots, and
higher quantities of spots mean more activity.
Space Weather
Chris Hootton
Across the next few issues of Touchline we will be exploring a risk that not many are familiar with that
could be set to have an increasing influence over the next few years. We will begin by looking at the
origins and effects of space weather upon Earth and then go on to investigate the impacts on sport and
business.
Types of Space Weather:
Spectacular
Solar Flares
are explosions on the Sun’s
surface caused by a release of magnetic energy where
magnetic fields arch over and reconnect with the surface,
possibly up to tens of thousands of kilometres away. Flares
are more frequent and intense during ‘maximums’ and
the released electromagnetic radiation can reach Earth
in just eight minutes. Despite their dazzling appearance,
the effects of Space Flares are mostly limited to disrupting
and blocking radio transmissions and disturbing GPS
signals. The largest ever Solar Flare recorded occurred in
1859 (Carrington Event) causing telegraph systems across
Europe and North America to fail and auroras were seen as
low as the Caribbean.
Solar winds
present the most constant form of space
weather. The Sun emits a low density wind of ionised
matter, better known as plasma, which is hot enough to
escape the Sun’s gravitational field. Our planet is protected
from this plasma by our very own magnetic field, called the
magnetosphere, however when solar winds are particularly
strong this magnetosphere is compressed. This can cause
satellites orbiting in the magnetosphere to be exposed to
electrostatic charging and potentially damaging discharges.
Not all of this energy is deflected by the magnetosphere,
and there are two belts of radiation that permanently encircle
Earth, called the Van Allen radiation belts.
Coronal Mass Ejections
(CMEs) pose the greatest threat to
Earth because of their potential effects on our infrastructure.
A CME is when magnetic fields on the Sun, similar to the
arching magnetic fields of solar flares, become unstable or
snap causing the energy to be fired into space. CMEs and
Solar Flares are the biggest explosions in our solar system
and these denser high speed bursts of energy from CMEs
can reach Earth in a day or so and roughly approach the
power of one billion hydrogen bombs. CMEs are dangerous
when combined with solar winds as the CME has the effect
of compressing the magnetosphere resulting in intensified
electric currents in the magnetosphere which rapidly
changes the Earth’s magnetic field. It is these ‘magnetic
storms’ that cause the aurora borealis (Northern Lights)
and can disrupt operation of power grids, pipelines, railway
signalling, magnetic surveying and drilling for oil and gas.
Other space weather worth a mention include:
• Galactic Cosmic rays
- charged particles from
outside our solar system that can affect satellites/
spacecraft and penetrate the atmosphere to
damage systems in aircraft on the ground
• Solar Radio Bursts
– strong bursts of natural radio
emissions from the Sun that can interfere with radio
signals and wireless technologies
• Proton Flares
– much less common, but more
damaging to satellites than Solar Flares
F