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 —
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- 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.
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