- 4607 -
GEOMAGNETIC STORM - are they harmful? A geomagnetic storm lit up the night sky
in parts of the U.S. during the first weekend in October. The storm had
originated from a solar flare that erupted from “sunspot 3842” on October 3,
2024.
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---------------------------------- 4607 - GEOMAGNETIC STORM - are they harmful?
- This was the strongest Earth-facing solar
flare recorded by “Sansa” in the past seven years and that the eruption briefly
affected high-frequency radio communications, resulting in a total radio
blackout over the African region which lasted for up to 20 minutes.
-
- A geomagnetic storm is a disturbance in
Earth's magnetic field caused by solar activity. There's a reaction called
nuclear fusion that occurs continuously deep within the sun's core. This
generates massive amounts of energy. Some of the energy is released as light
(sunlight), some as radiation (solar flares), and some as charged particles.
-
- The sun also continuously emits a stream of
charged particles known as the solar wind.
Occasionally, the sun releases larger bursts of energy, called “coronal
mass ejections”. It sends clouds of these charged particles, or plasma,
hurtling through space. This
"burp" is the cloud of plasma which then travels through space. These
emissions don't always hit us. But when they do, they collide with Earth's
magnetic field, disrupt it, and lead to a geomagnetic storm.
-
- Earth's magnetic field is an invisible force
that surrounds our planet, acting like a giant magnet with a north and south
pole. It helps protect us from harmful solar radiation by deflecting charged
particles from the sun.
-
- The solar flare from “3842” emitted both
X-flares (radiation) and a coronal mass ejection. X-flares are radiation; they
travel at almost the speed of light and reach Earth within minutes. That's what
caused the brief communications disruption Sansa mentioned on 3 October. But
the coronal mass ejection takes much longer to reach us.
-
- Geomagnetic storms occur fairly often.
Minor ones happen multiple times per year. The severity of a storm depends on
how strong the solar event was that caused it. Larger, more intense storms are
less common but can happen every few years.
-
- Solar events are closely tied to the sun's
11-year solar cycle, which has periods of high and low activity. During the
peak of the cycle, called solar maximum, more sunspots and solar flares occur,
increasing the likelihood of solar storms.
We are now heading towards the peak of Solar Cycle 25, which will be in
July 2025. Solar maxima usually last between two and three years.
-
- Are these storms dangerous? What damage can
they cause? Geomagnetic storms are not
typically harmful to humans directly, but they can pose risks to modern technology
and infrastructure. One of the most notable dangers is to power grids. Powerful
storms can induce electric currents in power lines, potentially overloading
transformers and causing blackouts, as happened in Quebec, Canada, in 1989.
-
- Satellites in space are also vulnerable. A
strong storm can damage electronics onboard, disrupt communication signals, and
shorten the lifespan of the satellites themselves.
-
- In aviation, geomagnetic storms can disrupt
radio communication and GPS signals, which are vital for aircraft navigation.
This is especially important for flights that pass near the polar regions,
where the effects of geomagnetic storms are more pronounced. Astronauts and
spacecraft are also at risk. The extra
radiation can be dangerous for equipment and human health.
-
- Auroras are a visually stunning aspect of
geomagnetic storms. These colorful displays in the night sky occur when charged
particles from the sun get captured in Earth's magnetic field lines, and funnel
down towards the poles. Here they interact with Earth's atmosphere, releasing
energy that produces shimmering lights.
-
- Auroras can be seen at both the north and
south poles, aptly named the northern and southern lights. If storms are big
enough, it's possible to see them in regions much further away from the poles.
This happened in South Africa on 11 May 2024.
-
- Studying geomagnetic storms provides
valuable insights into space weather. By understanding how the sun's activity
affects Earth, scientists can better predict future storms and work to protect
the technologies we rely on. The study of geomagnetic storms also contributes
to our understanding of the sun and space in general.
-
- Geomagnetic storms are monitored using
various instruments on Earth and in space. On Earth, magnetometers measure
changes in the magnetic field, allowing scientists to track disturbances as
they happen.
-
- “Sansa” operates a dense network of Global
Navigation Satellite System receivers in Africa, and magnetometer stations in
various parts of southern Africa, for this reason. The agency is currently
setting up a magnetometer station in Ethiopia, too. This will improve our
ability to monitor geomagnetic storms.
-
- In space, satellites equipped with sensors
monitor the sun's activity and detect solar flares or coronal mass ejections
before they reach Earth. This data feeds into prediction models used in space
weather centers across the globe.
-
- Once a storm is detected, agencies like
Sansa issue alerts and forecasts. These warnings help industries such as power
grid operators, satellite companies and aviation authorities to prepare for a
storm.
-
- For example, power companies can temporarily
shut down or reconfigure parts of the grid to avoid overloading during a storm.
Satellite operators can place their spacecraft into safer operating modes, such
as switching off electronic components, and airlines can reroute flights away
from high-risk areas.
-
- Monitoring alone can't prevent all the
damage caused by geomagnetic storms. But it can greatly reduce the risks.
Thanks to early warning systems, we can protect crucial infrastructure and
minimize the effect these storms have on our daily lives.
-
-
November 12, 2024 GEOMAGNETIC STORM -
are they harmful? 4607
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------ “Jim Detrick” -----------
--------------------- --- Wednesday, November 13,
2024
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