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


About the ‘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 energised, 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.