infrastructure affected by space weather events. Credit: NASA
Illustration of the various dynamic
and constant solar effects on Earth. The two solar constants, sunlight and solar
wind, takes 8 minutes and 4 days, respectively, to reach Earth. Arrival times of
dynamic solar events such as Flares, solar energetic particles and CMEs, are
approximated and range from immediate effect to several days. Credit:
solar flares release very-high-energy particles that can be as injurious to
humans as the low-energy radiation from nuclear blasts. Earth's atmosphere and
magnetosphere allow adequate protection for us on the ground, but astronauts in
space are subject to potentially lethal dosages of radiation. The penetration of
high-energy particles into living cells, measured as radiation dose, leads to
chromosome damage and, potentially, cancer. Large doses can be fatal
immediately. Solar protons with energies greater than 30 MeV are particularly
hazardous. In October 1989, the Sun produced enough energetic particles that an
astronaut on the Moon, wearing only a space suit and caught out in the brunt of
the storm, would probably have died.
communication systems utilize the ionosphere to reflect radio signals over long
distances. Ionospheric storms can affect radio communication at all latitudes.
Some radio frequencies are absorbed and others are reflected, leading to rapidly
fluctuating signals and unexpected propagation paths. TV and commercial radio
stations are little affected by solar activity, but ground-to-air,
ship-to-shore, Voice of America, Radio Free Europe, and amateur radio are
frequently disrupted. Radio operators using high frequencies rely upon solar and
to keep their communication circuits up and running.
military detection or early-warning systems are also affected by solar activity.
The Over-the-Horizon Radar bounces signals off the ionosphere in order to
monitor the launch of aircraft and missiles from long distances. During
geomagnetic storms, this system can be severely hampered by radio clutter. Some
submarine detection systems use the magnetic signatures of submarines as one
input to their locating schemes. Geomagnetic storms can mask and distort these
flares can also doom satellites. Reaching the earth in just eight minutes, their
powerful UV and X rays help heat up and expand the atmosphere, thereby
increasing molecular drag on low-orbiting satellites and shortening their
orbital life. Another problem for satellites differential charging. During
geomagnetic storms, the number and energy of electrons and ions increase. When a
satellite travels through this energized environment, the charged particles
striking the spacecraft cause different portions of the spacecraft to be
differentially charged. Eventually, electrical discharges can arc across
spacecraft components, harming and possibly disabling them.
(also called deep charging) occurs when energetic particles, primarily
electrons, penetrate the outer covering of a satellite and deposit their charge
in its internal parts. If sufficient charge accumulates in any one component, it
may attempt to neutralize by discharging to other components. This discharge is
potentially hazardous to the satellite's electronic systems.
magnetic fields move about in the vicinity of a conductor such as a wire, an
electric current is induced into the conductor. This happens on a grand scale
during geomagnetic storms. Power companies transmit alternating current to their
customers via long transmission lines. The nearly direct currents induced in
these lines from geomagnetic storms are harmful to electrical transmission
& Gas Pipelines
fluctuating geomagnetic fields can induce currents into pipelines. During these
times, several problems can arise for pipeline engineers. Flow meters in the
pipeline can transmit erroneous flow information, and the corrosion rate of the
pipeline is dramatically in creased. If engineers unwittingly attempt to balance
the current during a geomagnetic storm, corrosion rates may increase even more.
Pipeline managers routinely receive alerts and warnings to help them provide an
efficient and long-lived system.
most often glow green, the color emitted by oxygen atoms high in the upper
atmosphere after they are struck by bombarding electrons from Earth's
magnetosphere. Red displays are rarer, sometimes involving energized nitrogen
molecules lower down in the atmosphere -- an indication of a more potent
geomagnetic storm. Auroras that extend away from the poles and closer to the
equator also reflect strong storm conditions.
Northern Lights/Southern Lights, or Aurora Borealis, is natures own gigantic light-show. An
Aurora Borealis occurs when the particles from the sun are being thrown against
the earth by the solar wind. When the particles collide with the earths
atmosphere, the energy of the particles are turned into light.
The Mystery of the Aurora
NOAA Space Weather Scale for Solar Radiation Storms
(1 cycle = 11 years)
Duration of event will influence severity of
Solar Radiation Storms
Flux level of >= 10 MeV particles (ions)*
Number of events when flux level was met (number of storm days**)
Biological: unavoidable high radiation hazard to astronauts on
EVA (extra-vehicular activity); high radiation exposure to passengers
and crew in commercial jets at high latitudes (approximately 100 chest
x-rays) is possible.
Satellite operations: satellites may be rendered useless,
memory impacts can cause loss of control, may cause serious noise in
image data, star-trackers may be unable to locate sources; permanent
damage to solar panels possible.
Other systems: complete blackout of HF (high frequency)
communications possible through the polar regions, and position errors
make navigation operations extremely difficult.
Fewer than 1 per cycle
Biological: unavoidable radiation hazard to astronauts on EVA;
elevated radiation exposure to passengers and crew in commercial jets at
high latitudes (approximately 10 chest x-rays) is possible.
Satellite operations: may experience memory device problems
and noise on imaging systems; star-tracker problems may cause
orientation problems, and solar panel efficiency can be degraded.
Other systems: blackout of HF radio communications through the
polar regions and increased navigation errors over several days are
3 per cycle
Biological: radiation hazard avoidance recommended for
astronauts on EVA; passengers and crew in commercial jets at high
latitudes may receive low-level radiation exposure (approximately 1
Satellite operations: single-event upsets, noise in imaging
systems, and slight reduction of efficiency in solar panel are likely.
Other systems: degraded HF radio propagation through the polar
regions and navigation position errors likely.
compiled from The British Antarctic Study, NASA, Environment Canada,
UNEP, EPA and other sources as stated and credited Researched by Charles
Welch-Updated daily This Website is a project of the The Ozone Hole Inc.
a 501(c)(3) Nonprofit Organization http://www.theozonehole.com