About Geomagnetic Storm

• A geomagnetic storm is a disturbance in the earth’s magnetosphere, which is the area around the planet controlled by its magnetic field.
• The earth’s magnetosphere protects its inhabitants from most of the particles emitted by the sun.
• When a coronal mass ejection (CME) or a high-speed stream reaches the earth, it strikes the planet’s magnetosphere.
• If the incoming solar magnetic field is directed southwards, it interacts strongly with the earth’s own magnetic field that is opposite in direction, causing disturbances.
• A coronal mass ejection is a large expulsion of plasma and magnetic field from the sun’s corona. Plasma is the highly ionised gas present on the sun, while corona is the outermost part of the sun’s atmosphere.
• The corona is structured by strong magnetic fields. If these fields are closed, the solar atmosphere can release sudden, violent bubbles of gas and magnetic fields which constitute the CME.
• The changes produced in the earth’s magnetic field as a result of this interaction allow solar wind particles to stream down the magnetic field lines and hit the atmosphere near the poles.
• Solar winds deeply impact the shape of the earth’s magnetosphere, and variations in solar winds cause geomagnetic storms on earth.
• At the surface of the earth, a geomagnetic storm can result in a rapid decline in the earth’s magnetic field strength. This decrease can last for around 6 to 12 hours and gradually recovers over several days.
• Geomagnetic storms can impact long-range radio communication and global positioning system (GPS) devices.
• These storms can also damage satellite electronics and expose astronauts and high-altitude pilots to increased levels of radiation.
• Voltage surges due to altered magnetic activity can also affect power supply on the earth and cause outages.
• Geomagnetic storms are also linked with intensified northern lights visible in the skies of higher latitudes.

Source: Forum IAS