Solar storms are known to be responsible for some major electrical
disruptions and satellite failures:
Although the Sun is 150 million kilometers away, the sudden expulsion
of particles and gas that we see in solar
flares and coronal mass ejections can have
a strong effect on the Earth. This intimate connection between
physical processes at the Sun and changes in the Earth's magnetic
environment has been dubbed Space
Copyrighted to Jan Curtis
One of the more benign consequences of Space Weather is the aurorae, which we know better as the Northern
and Southern Lights. A bright aurora signifies a strong disturbance
in the upper atmosphere and magnetic field of the Earth. However,
much of what we call Space Weather is invisible to the naked eye and
can have much more severe consequences.
Strange terrestrial electrical effects have been related
to events on the Sun for a little over 100 years. But it is only in
the last decade or so that our reliance on the technology of satellite
communications (cell phones, pagers and the like), high altitude
flights, and long-term manned space exploration, that the effects of
solar storms have become important to society at large.
Satellites are particularly vulnerable to the electrical
effects of Space Weather as they are buffeted by the incoming gas and
radiation. There is also a less obvious but equally costly effect to
satellites in near-Earth orbits, caused by the increased radiation
hitting the Earth's atmosphere.
The extra energy of charged particles
and ionizing radiation causes the atmosphere of the Earth to expand,
which, in turn, creates extra drag on the satellites orbiting the
Earth. It is estimated that more than 1500 satellites slowed in their
orbit or lost several kilometers of altitude as a result of the great
storms of March 1989.
The effects of solar storms on the ground can
also be expensive. Magnetic storms can change the Earth's magnetic
field producing surges in power lines and long uninterrupted
oil and gas pipelines. The extra current in the power lines can
burn out transformers, leading to large-scale brownouts or blackouts,
while the electricity in pipelines can enhance the rate of
corrosion. It is estimated that transformer failures across the US
and Canada cause $100 million in equipment damage each sunspot
A map of North America showing the various electrical service problems recorded during the March 13 1989 storm.
PJM Public Service Step-Up Transformer: Severe internal damage caused by the space storm of March 13 1989.
Both images from IMAGE/POETRY website.
Solar storms are known to be responsible for some major electrical disruptions and satellite failures:
At the beginning of the 21st century, we are all very familiar with
space; some of you may even be thinking of a future vacation on a
space shuttle or a quick 90-minute cruise around the globe. As our
physical presence in space increases, we need to be more aware of the
dangers that solar storms can present. The construction of the
International Space Station will require that astronauts be out in
open space for considerable lengths of time. If a solar flare or CME
occurs during one of those space walks, the radiation received by that
astronaut can easily exceed her permitted yearly dosage,
effectively grounding her for 12 months.
Some of the best defenses against the effects of storms come in the early design stages, especially of satellites. By adding radiation shielding to sensitive electronics much of the damage of solar storms can be avoided. This is costly, but in some cases worth the additional expense.
|A network of solar observing stations around the globe and in space are used to constantly monitor the behavior of the Sun, providing a measure of predictive capability for solar storms. Like its counterpart on the Earth, Space Weather is a complicated system and making forecasts can sometimes be hit or miss. As we learn more about the physical processes behind the production of solar flares and coronal mass ejections our ability to forecast potentially dangerous disruptions will improve. We are in space for good now, and like sailors of old, we will need to 'weather the storm.'|
For a look at today's Space Weather forecast visit the Space Weather Bureau.
For a set of student activities on solar storms see Solar Storms and You!
The Active Sun