|
This view of the Aurora
Australis (Southern Lights) shows a sinuous looping band of
airglow above the Earth Limb.
photo courtesy of NASA
Image Exchange |
Strong solar activity can lead to geomagnetic storms, which are created
when charged solar particles hit the earth’s magnetic field with
enough force to bend it. These storms can lead to spectacular visual
effects, but they also can have catastrophic effects on electrical
systems, animals and our health.
During the 2001 solar maximum, residents as far south as Mexico
got the once-in-a-lifetime chance to see the northern
lights, or aurora borealis, normally seen only at latitudes
around the Arctic Circle. Many people around the world sighted bright
red glowing skies with thin, light green streaks shimmering on the
horizon. From our view, it simply looks like a light show, but an
event like this actually means that the earth’s magnetic field is
being pummeled by solar winds. The greater the intensity of these
winds, the farther south the geomagnetic disturbance spreads, giving
people an opportunity to check out the northern lights.
But also as a result of geomagnetic storms, technology we use every
day can be destroyed in a matter of seconds. Here, the ability to
predict space weather becomes crucial; it allows us to prepare for
and minimize solar damage to the systems upon which we rely. During
the last solar peak in 1989, six million people in Quebec
were left without electricity for nine hours, and in New Jersey,
a multi-million-dollar power transformer melted down. At the same
time, Minnesota residents lost their local radio programs and found
themselves tuned into highway patrol messages from California.
|
 |
|
geomagnetic storm
A geomagnetic storm occurs when unusually strong surges of solar wind
(charged particles from the sun) hit the Earth. This effect causes variations
in the magnetic field which surrounds the Earth.
|
| |
|
Satellites can fall back into the Earth’s atmosphere and burn up as a result of
strong solar activity. By being aware of this, corrective action such as boosting
the satellites to keep them in orbit can be taken. Satellites can also develop
electrical problems; damaged GPS navigation satellites can throw off GPS calculations by several miles.
In order to schedule their work, geologic surveyors studying the Earth’s magnetic
field for oil, gas and mineral deposits need information on geomagnetic storms.
Some surveyors prefer to work when the Earth’s magnetic field is quiet; while others
enjoy storm interference because they claim it enables them to see better.
In order to schedule their work, geologic surveyors studying the Earth’s
magnetic field for oil, gas and mineral deposits need information on geomagnetic
storms. Some surveyors prefer to work when the Earth’s magnetic field is quiet;
while others enjoy storm interference because they claim it enables them to see better.
Electricity providers have to measure whether any disturbances will
affect their electric lines. If problems are expected, they can reroute
more power through other lines. The same goes for oil pipeline managers.
Pipelines can be affected because the pipes’ corrosion rate increases during
geomagnetic storms. Solar storm warnings help managers monitor the effect
on their pipelines and take appropriate action to dampen the damage.
Meanwhile, for scientists who study the ins and outs of the sun, there’s
much to speculate about. Scientists have noted that the sun’s energetic
output does vary during the 11-year cycle. Studying the growth of plants
and trees is one way they speculate about the effects of the sun’s energetic
output on the Earth’s climate. By examining a tree’s rings of growth, they
believe that if the sun’s energy decreases by even a tenth of a percent,
this can mean a change in the tree’s rate of growth.
|
An eruption from a solar flare can be as dangerous to astronauts in outer
space as any nuclear blast is to humans on earth.
photo courtesy of NASA
Image Exchange |
Ever wonder how animals migrate from one place to the other?
They don’t have road maps like we do, but they do have their own built-in
compasses. Inside their nerve cells, they have a mineral called magnetite,
which scientists believe is one tool that animals use to get from Point
A to B, and back again. Dolphins, whales and other migratory animals
(such as homing pigeons) have this. When homing pigeons have flown away
during geomagnetic storms, they have sometimes not returned, leaving
scientists to surmise that their navigational ability was affected by the storms.
An eruption from a solar flare can be as dangerous to astronauts in outer
space as a nuclear blast is to humans on earth. Astronauts who are caught
outside in space during a violent storm can die their spacesuits wouldn’t
be enough protection. Avoiding these storms is the best option even when
inside a spacecraft. Pilots of supersonic aircraft also need to be aware of
solar activity, especially when they are flying above the polar caps - radiation
from solar storms is stronger here because solar particles tend to travel along
magnetic field lines to the North and South Poles.
|