Geomagnetic storm

A geomagnetic storm is a temporary disturbance of the Earth's magnetosphere caused by a disturbance in space weather. Associated with solar flares and resultant solar coronal mass ejections (CME), a geomagnetic storm is caused by a solar wind shock wave and/or cloud of magnetic field which typically strikes the Earth's magnetic field 3 days after the event. The solar wind pressure on the magnetosphere and the solar wind magnetic field will increase or decrease depending on the Sun's activity. The solar wind pressure changes modify the electric currents in the ionosphere, and the solar wind's magnetic field interacts with the Earth's magnetic field causing the entire structure to evolve. Magnetic storms usually last 24 to 48 hours, but some may last for many days.


Interactions with planetary processes


The solar wind also carries with it the magnetic field of the Sun. This field will have either a North or South orientation. If the solar wind has energetic bursts, contracting and expanding the magnetosphere, or if the solar wind takes a southward polarization, geomagnetic storms can be expected. The southward field causes magnetic reconnection of the dayside magnetopause, rapidly injecting magnetic and particle energy into the Earth's magnetosphere.


During a geomagnetic storm, the ionosphere's F2 layer will become unstable, fragment, and may even disappear. In the northern and southern pole regions of the Earth, auroras will be observable in the sky.


Geomagnetic storm effects
Drumlin – an elongated whale-shaped hill formed by glacial action.
Radiation hazards to humans
Biology
Disrupted systems
Communications
Navigation systems
Satellite hardware damage
Geologic exploration
Electric grid
Pipelines

                                                               aurora polaris