South Atlantic Anomaly (SAA):
- However, a rapid shrink has been observed in the South Atlantic Anomaly (SAA), a stretch between Africa and South America. It is an area where the Earth's inner Van Allen radiation belt comes closest to the Earth's surface, dipping down to an altitude of 200 kilometres.
- This leads to an increased flux of energetic particles in this region and exposes orbiting satellites to higher-than-usual levels of radiation.
- The effect is caused by the non-concentricity of the Earth and its magnetic dipole. The SAA is the near-Earth region where the Earth's magnetic field is weakest relative to an idealized Earth-centered dipole field.
Pole reversal:
- One most speculated reason behind this is that there is a chance that the time for Earth's pole reversal is coming near.
- Pole reversal is when the north and south magnetic poles flip. While this flip will not occur immediately or suddenly, and will happen over centuries, there would be multiple north and south magnetic poles during this period, all around the planet.
- This is definitely not the first time that pole reversal will be happening on the Earth. This event has occurred few times in the history of our planet, as per the scientists and we are long overdue by the average rate at which these reversals take place (roughly every 250,000 years).
Impact:
- This is not going to affect or alarm the general public to a huge extent.
- But it is causing technical difficulties for various satellites and spacecrafts, as the magnetic field getting weaker, charged particles from the cosmos can penetrate through to the altitudes that low-Earth orbiting satellites fly at.
