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GEOMAGNETIC STORMS

18th May, 2024 Geography

GEOMAGNETIC STORMS

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Picture Courtesy: https://www.istockphoto.com/vector/magnetic-field-that-protected-the-earth-from-solar-wind-gm1084168988-290886456

Context: Earth experienced the most intense geomagnetic storm in over two decades, causing widespread radio blackouts and extending the visibility of the northern lights to the southern United States.

About Geomagnetic Storm

  • A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere, which is caused by a shock wave from the solar wind. This disturbance can be triggered by solar coronal mass ejections (CMEs) or, less severely, by co-rotating interaction regions (CIRs) originating from solar coronal holes.

Causes

  • Solar Coronal Mass Ejections (CMEs): Large expulsions of plasma and magnetic field from the Sun's corona that can reach Earth and impact its magnetosphere.
  • Co-rotating Interaction Regions (CIRs): High-speed streams of solar wind that interact with slower solar wind streams, creating areas of enhanced magnetic and plasma activity.

Mechanism

  • Initial Compression: The increased solar wind pressure compresses the Earth's magnetosphere.
  • Energy Transfer: The magnetic field of the solar wind interacts with the Earth's magnetic field, transferring energy into the magnetosphere.
  • Plasma Movement: The interaction increases the movement of plasma within the magnetosphere and the electric current in the magnetosphere and ionosphere.
  • Boundary Shifts: The increased electric current creates a magnetic force that pushes the boundary between the magnetosphere and the solar wind outward.

Effects of Geomagnetic Storms

  • Solar Energetic Particle (SEP) Events: High-energy particles from the Sun that can affect satellites and spacecraft.
  • Geomagnetically Induced Currents (GICs): Currents induced in power grids and pipelines that can cause equipment damage and power outages.
  • Ionospheric Storms: Disturbances in the ionosphere that can disrupt radio communications and GPS signals.
  • Auroral Displays: Enhanced auroras are visible at much lower latitudes than usual.

Dst Index measures changes in the Earth's magnetic field; a key metric for defining and understanding geomagnetic storms.

Impact on Technology and Infrastructure

  • Electrical Systems: GICs can damage transformers and power grids, leading to widespread power outages.
  • Communication Systems: Radio and satellite communications can be disrupted, affecting aviation and military operations.
  • Satellites: Increased drag due to atmospheric expansion can alter satellite orbits, and radiation can damage satellite electronics.
  • Pipelines: GICs can increase corrosion rates, affecting the integrity of pipelines.

Human and Environmental Effects

  • Radiation Hazards: Increased radiation can pose health risks to astronauts and high-altitude flight crews.
  • Effects on Animals: Some studies suggest geomagnetic storms may impact animal navigation, particularly in species that rely on magnetoreception, like birds and whales.

Conclusion

  • Geomagnetic storms are complex phenomena resulting from solar activity that can significantly impact technological systems and infrastructure on Earth. Understanding and monitoring these storms is crucial to mitigate their effects.

Must Read Articles:

Geomagnetic Storm

Source:

EARTH

Wikipedia

PRACTICE QUESTION

Q. Consider the following statements:

Statement 1: Geomagnetic storms can cause significant disruptions to satellite communications.

Statement 2: Geomagnetic storms induce electric currents in the Earth's atmosphere.

Which one of the following is correct in respect of the above statements?

A) Both Statement-1 and Statement-2 are correct and Statement-2 is the correct explanation for Statement-1

B) Both Statement-1 and Statement-2 are correct and Statement-2 is not the correct explanation for Statement-1

C) Statement-1 is correct but Statement-2 is incorrect

D) Statement-1 is incorrect but Statement-2 is correct

Answer: A