Geomagnetic storm

Relatively low energy cosmic rays from the Sun

Celestial power: Quebec in the dark

In March 1989 Quebec's power grid system was disrupted by strong variations in the Earth's magnetic field. The change in the magnetic field produced strong currents which were flowing through the power lines causing a severe voltage surge. Since Quebec sits on a rock shield with high electrical resistance it could not provide a good electrical grounding. A power blackout ensued. Further consequences of geomagnetic storms:
  • failure of satellites
  • corrosion of pipelines
  • disruption of electrical communication and navigational systems
Aurora australis Aurora
Figure 1: Aurora australis; picture taken from NASA's IMAGE satellite 11. September 2005
image credit: NASA source:

What is the reason for Auroras?

The Earth is permanently hit by cosmic ray particles. Close to the magnetic poles of the Earth one can frequently see light phenomena, so-called auroras, due to the interaction of charged cosmic ray particles with particles of the Earth's atmosphere. The Earth has a magnetic field which is generated by electrical currents in the core. The trajectory of a charged particle is bent in presence of magnetic field lines. Charged particles with a particular energy can be trapped by the magnetic field of the Earth and perform a spiraling motion along the field lines where they finally reach the magnetic poles.
Click on the picture above to see an animation explaining an aurora

How could so many charged particles from the Sun reach the Earth in Canada?

A coronal mass ejection can trigger a tremendous geomagnetic storm which results in the disturbance of the Earth's magnetosphere. Charged particles enter the geomagnetic sphere (see Figure 2).
solar wind and magnetosphere
Figure 2: Ejection of charged particles from the Sun's surface and its impact on the Earth's magnetosphere
image credit:

Last modified: 23 Aug 2012, 09:23 CET