What is a Solar storm
(solar flare)?
Continuous
wind of Electrically charged gas that is propelled away from the sun in all
directions.
It
occurs when magnetic energy builds up in the solar atmosphere and is released suddenly.
Coronal mass ejection [CME] Vs Solar Flare
What | phenomenon produced by sun |
| More disruptive than solar flare |
Solar Flare relation with the solar cycle
These outbursts are intrinsically linked to the solar cycle — an approximately 11-year cycle of solar activity driven by the sun's magnetic field.
Impact of Solar Flare
1. Earth,
satellites and even astronauts.[Esp. X-class flares]
2. Solar
flares can temporarily alter the upper atmosphere creating disruptions with
signal transmission from, say, a GPS satellite.
Why question asked?
Intense
solar flares posing a threat to specific regions of Asia were in news.
If a major solar storm (solar
flare) reaches the Earth, which of the following are the possible effects on
the Earth ?- UPSC pre 2022
1. GPS and navigation
systems could fail.
2. Tsunamis could
occur at equatorial regions.
3. Power grids
could be damaged.
4. Intense auroras
could occur over much of the Earth.
5. Forest fires
could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio
communication of the aircraft flying over
polar regions could be interrupted.
Select
the correct answer using the code given below :
(a) 1, 2, 4 and 5 only
(b) 2, 3, 5, 6 and 7 only
(c) 1, 3, 4, 6 and 7 only
(d) 1, 2, 3, 4, 5, 6 and 7
Solution
C
Analysis
Easy
and Random questions can be put in S&T and Geography but I would consider it an S&T question in space technology.
Why Easy?
Tsunamis
occur due to earthquakes in the ocean.
It does not occur by solar flares.
Similarly, forest fires occurring over much of the planet's Extreme statement can be easily
eliminated.
====================================
🕱Now Things are going to be technical and you might feel that it is
not required for UPSC. But I am discussing this to ensure you understand the
topic thoroughly.
More Technical Explanation of
Solar Flare and How it is Created?
A solar flare is an intense localized eruption of electromagnetic radiation in the
Sun's atmosphere.
Flares
occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and
other solar phenomena.
Solar flares affect all layers of the solar atmosphere (photosphere, chromosphere, and corona).
The
plasma medium is heated to tens of millions of kelvins, while electrons,
protons, and heavier ions are accelerated to near the speed of light.
What is Plasma?
According
to MIT
Plasma
is often called “fourth state of matter,” along
with solid, liquid and gas.
Just
as a liquid will boil, changing into a gas when energy is added, heating a gas
will form a plasma – a soup of positively charged particles (ions) and
negatively charged particles (electrons).
The magnetic field is stronger at poles because magnetic field lines are very close to each
other near the poles.
How is Solar wind created?
The
solar wind is created by the outward expansion of
plasma (a collection of charged particles) from the Sun's corona
(outermost atmosphere).
This
plasma is continually heated to the point that the
Sun's gravity can't hold it down. It then travels along the Sun's
magnetic field lines that extend radially outward.
Flares
produce electromagnetic radiation across the electromagnetic spectrum at all wavelengths, from radio waves to gamma rays.
Most
of the energy is spread over frequencies outside the
visual range; the majority of the flares are not
visible to the naked eye and must be observed with special instruments.
Flares
occur in active regions often around sunspots, where intense magnetic fields
penetrate the photosphere to link the corona to the solar interior.
Flares
are powered by the sudden release of magnetic energy stored in the corona.
The
same energy releases may produce coronal mass ejections
(CMEs), although the relationship between CMEs and flares is still not
well understood.
Statement 6. Orbits of the satellites could be disturbed.
How Solar Flares Impact
Satellite?
The
scientists found that solar flares and storms heated and expanded the
atmosphere and that these effects could extend to the satellites’ orbits.
The
density of atmospheric gases increases, slowing the satellites and causing them
to lose altitude by a few kilometers per day.
Statement 5. Forest fires could take place over much of
the planet.
According
to NASA, harmful
radiation
from a flare cannot pass through Earth’s
atmosphere
to physically affect humans on the ground.
The solar flares, even the intense ones, do not pose an immediate threat to us, at least those who are within the Earth's atmosphere.
Flares
are not fires but
outbursts of electromagnetic radiation.
Thus they will not cause forest fires. Hence statement 5 is not correct.
Statement 2. Tsunamis could occur in equatorial regions.
Tsunami
is a purely seismic phenomenon.
What are the things that can potentially cause Tsunami?
Earthquakes,
volcanic
eruptions and
other
underwater explosions
(including
detonations,
landslides,
glacier calving[breaking of ice chunks from the edge of a glacier.],
meteorite
impacts and other disturbances) above or
below
water, all have the potential to generate a
tsunami
and not solar flares.
Statement 4 -Intense auroras
could occur over much of the Earth.
 |
| Aurora - image credit - National Geographic |
What is Aurora and How it occurs?
Aurora is a natural phenomenon which is characterised by a display of a natural-coloured (green, red, yellow or white) light in the sky.
Auroras
occur when charged particles (electrons and protons) collide with gases in
Earth's upper atmosphere.
Those
collisions produce tiny flashes that fill the sky with colourful light.
If
you're near the North Pole, it is called an aurora
borealis or northern lights. If you're near the South Pole, it is called
an aurora australis or the southern lights.
Can Auroras Occur near
Equator?
Yes, but it takes a lot of very energetic particles being ejected by the sun over
a brief period.
Strong
M-class and X-class solar flares can trigger coronal
mass ejections — a large release of plasma and magnetic field from the
sun.
This behaviour can disrupt Earth's magnetosphere and result in geomagnetic storms.
Such
geomagnetic storms can lead to auroras closer to the equator than is possible
during calm conditions.
Comments
Post a Comment