In 2012, the Sun is entering the highest activity period of its 22-year cycle, so the next few years are certain to produce some memorable solar storms. The Earth’s magnetic field and ionosphere deal well with mild to moderate solar storms, but extreme solar storms could overwhelm them. Even a moderate solar storm could expose geosynchronous communications satellites and lower-orbiting GPS satellite constellations to damaging induced currents.
Radio communications
In normal solar weather, most shortwave radio waves are absorbed in the Earth’s stratosphere, while all long wave radio waves bounce off the ionosphere. During high intensity solar flares, so much solar radiation is released that the ionosphere itself is affected.
This can disrupt radar and other radio transmissions, which rely on ionosphere reflection for long-distance communication. Even radio communications which are not lost in the ionosphere may be snowed under by the deluge of radio waves from the sun.
Loss of radar and radio transmissions also pose a risk to high altitude flights. Great circle routes often take aircraft near the North Magnetic Pole, where the navigator may lose satellite contact as well as radio contact. These flights are usually rerouted during a major solar storm.
Cell phones
Cell phones operate on a radio frequency transmitted by a series of cellular towers. The same charged solar particles which are responsible for the aurora borealis can also induce currents in those towers. These will certainly disrupt radio transmission, and may even be too strong for the towers to handle. If enough cellular towers are disrupted or destroyed, cell phone use may be lost over a large area, possibly for an extended period of time.
An equivalent event has happened once before, on a much smaller scale. On September 1 and 2, 1859, the Earth was bombarded by the strongest confirmed solar storm in human history. It started with a solar flare which was so intense that the amount of sunlight briefly doubled. When the solar particles from the flare reached Earth, they were in opposite alignment with the Earth’s magnetic field and were strong enough to overwhelm it. Auroras were visible as far south as Hawaii, with the New York Times reporting that in Boston, the aurora was “so brilliant that about one o’clock ordinary print could be read by [its] light.”
The auroral current was strong enough to short out most telegraph wires and even cause fires. In a few rare cases, telegraph operators were able to cut off their battery power and communicate using only the geomagnetically induced current. However, the overall damage greatly outweighed these few exceptions.
Communications and GPS satellites
During a strong coronal mass ejection (CME), the charged particles of the solar wind may compress the “windward” side of Earth’s magnetic field to the point that geosynchronous satellites are no longer protected by it. Uneven bombardment of ions can cause differential charges and arcing, which can damage communications and GPS satellites.
Low-Earth Orbit (LEO) satellites are also vulnerable to solar storms. Because of the expansion of the atmosphere when heated by increased radiation, these satellites will experience greater atmospheric friction than planned for, and may fall out of orbit faster than expected. In a worst-case scenario, a country may not be able to bring down a large LEO satellite safely into an ocean.
The radiation storm of 1994 was much less powerful than the 1859 solar storm, but it still damaged 2 Canadian communications satellites, which disrupted communications across Canada. The strongest effects of any solar storm are usually felt in Canada because it is the country whic currently contains the North Magnetic Pole. Effects in Canada are also further aggravated because isolated northern communities are particularly dependent on satellite communication.
However, every modern country today is highly dependent upon its GPS and communications satellites. Major cities depend on reliable communication for every part of their infrastructure to an unprecedented extent. GPS technology has transformed every part of society, from container ships at sea to horizontal oil drilling. A major solar storm could disrupt all that for hours, days, or possibly damage the equipment beyond repair.
The current solar cycle will continue to be on the upswing through 2013. Now is the time to ensure that emergency plans are prepared and backup systems are ready, just in case. After an 1859-style solar superstorm hits, it will be too late.
