Effects on Electronics and Communications

Space weather can interact both favorably and unfavorably with communications and electronics in a variety of ways. Geomagnetism, through geomagnetically induced currents, can damage transformers both slightly and severely. Solar activities can disrupt radio activities and directly harm spacecraft, but it is also directly responsible for much of our radio traffic.

Geomagnetically Induced Currents

Geomagnetically induced currents (GICs) can put transformers into a slight state of overload known as half-cycle saturation, where magnetism usually limited to the transformer core leaks out. This results in heat damage to the transformer. Usually, this damage does not actually cause a catastrophic failure, but instead merely accumulates and therefore limits the lifetime of the transformer to one much shorter than those untouched by GICs. However, rare large impulses can cause failure, such as happened in the Canadian Hydro-Quebec system on March 13, 1989, during a severe geomagnetic storm.

Solar Effects

Solar phenomena such as ionospheric storms and solar flares can interrupt high-frequency (HF) radio traffic considerably. Ionospheric storms do this by disrupting the path by which HF radio travels long distances, which is by 'bouncing' itself off the electrically active atoms in the ionosphere, then returning to Earth and 'bouncing' off the Earth, and repeating the process until the target location is reached. Solar flares create an absorption zone, where those HF waves are not allowed to bounce back to Earth.

However, the sun's effects are not all bad with regards to the HF radio traffic. The sun is actually the agent of action that created the ionosphere, by draining electrons out of the atmosphere with radiation. So, even though the sun sometimes interrupts HF traffic, it actually allows us to transmit any of it at all.

Some particles are actually ejected from the sun with enough force to cause damage to spacecraft. These particles are called SEPs (solar energetic particles). They cause a variety of damage, from direct radiation damage to such sections of spacecraft as solar arrays to a type of electrical buildup on some spacecraft designs that will actually flip bits, changing a zero into a one or vice versa. Sometimes, the solar wind and other planetary magnetic fields can combine to force the earth's magnetosphere inside orbit. When this phenomenon occurs, satellites are under much heavier attack from the solar particles, since much of it is usually blocked by the magnetosphere.

*National Geophysical Data Center.

**Space Environment Center.