What are Geomagnetic Storms?

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What are Geomagnetic Storms? Blog Image

Overview:

Recently, a Geomagnetic Storm was caused by a solar wind that passed through a gap created in the Earth’s magnetic field.

About Geomagnetic Storms:

  • A geomagnetic storm is a major disturbance of Earth's magnetosphere.
  • These storms result from variations in the solar wind that produces significant changes in the currents, plasmas, and fields in Earth’s magnetosphere.
  • The solar wind conditions that are effective for creating geomagnetic storms are sustained (for several hours) periods of the high-speed solar wind and a southward-directed solar wind magnetic field (opposite the direction of Earth’s field) at the dayside of the magnetosphere.
  • The largest such storms are associated with solar coronal mass ejections (CMEs), where a billion tons or so of plasma from the sun, with its embedded magnetic field, arrives at Earth. 
  • Effects:
  • These storms can heat the ionosphere, causing beautiful auroras on Earth.
  • Because the ionosphere is heated and distorted during storms, long-range radio communication that relies on sub-ionospheric reflection gets affected.
  • Ionospheric expansion due to these storms can increase satellite drag and make their orbits difficult to control.
  • Satellite electronics can be damaged through the build-up and discharge of static-electric charges.
  • It can disrupt global navigation systems.
  • It can create harmful geomagnetic-induced currents (GICs) in the power grid and pipelines.

What is a Solar wind?

  • It is a stream of energized, charged particles, primarily electrons and protons, flowing outward from the Sun through the solar system at speeds as high as 900 km/s and a temperature of 1 million degrees (Celsius).
  • It is made of plasma.
  • When the solar wind reaches Earth, it sends a flurry of charged particles toward the magnetosphere, along Earth's magnetic field lines, towards the poles.

What are Coronal Mass Ejections (CMEs)?

  • CMEs are large expulsions of plasma and magnetic field from the Sun’s corona that propagates outward into interplanetary space.
  • The blast of a CME carries about a billion tons of material out from the Sun at very high speeds of hundreds of kilometers per second.

 


Q1) What is the Earth’s magnetosphere?

Earth is surrounded by a system of magnetic fields, called the magnetosphere. The magnetosphere shields our home planet from harmful solar and cosmic particle radiation, as well as erosion of the atmosphere by the solar wind – the constant flow of charged particles streaming off the Sun.

Source: Geomagnetic storm hits Earth! Solar wind sparks red auroras in US