The March 1989 geomagnetic storm occurred as part of severe to extreme solar storms during early to mid March 1989, the most notable being a geomagnetic storm that struck Earth on March 13. This geomagnetic storm caused a nine-hour outage of Hydro-Québec's electricity transmission system. The onset time was exceptionally rapid. Other historically significant solar storms occurred later in 1989, during a very active period of solar cycle 22.
The geomagnetic storm causing this event was itself the result of an ejection known as a coronal mass ejection on March 9, 1989. A few days before, on March 6, a very large X15-class solar flare also occurred. Three-and-a-half days later, at 2:44 a.m. EST on March 13, a severe geomagnetic storm struck Earth. The storm began on Earth with extremely intense auroras at the poles. The aurora could be seen as far south as Texas and Florida. As this occurred near the end of the Cold War, an unknown number of people worried that a nuclear first strike might be in progress. Others incorrectly considered the intense auroras to be associated with the Space Shuttle mission STS-29, which had been launched on March 13 at 9:57:00 a.m. Substantial communications blackouts occurred. The burst caused shortwave radio interference, including the disruption of radio signals from Radio Free Europe into Russia. It was initially believed that the signals had been jammed by the Soviet government. As midnight came and went, a river of charged particles and electrons in the ionosphere flowed from west to east, inducing powerful electrical currents in the ground that surged into many natural nooks and crannies. Anecdotal evidence suggests that one of the UK's nuclear submarines noticed a variation in ELF signal strength around the same time. Because the MoD files are still classified, this is not yet possible to confirm or refute. Some satellites in polar orbits lost control for several hours. GOES weather satellite communications were interrupted, causing weather images to be lost. NASA's TDRS-1 communication satellite recorded over 250 anomalies caused by the increased particles flowing into its sensitive electronics. The Space Shuttle Discovery was having its own problems: a sensor on one of the tanks supplying hydrogen to a fuel cell was showing unusually high pressure readings on March 13. The problem went away after the solar storm subsided.
The variations in the Earth's magnetic field also tripped circuit breakers on Hydro-Québec's power grid. The utility's very long transmission lines and the fact that most of Quebec sits on a large rock shield prevented current flowing through the earth, finding a less resistant path along the 735 kVpower lines. The James Bay network went offline in less than 90 seconds, giving Quebec its second massive power outage in 11 months. The power failure lasted nine hours and forced the company to implement various mitigation strategies, including raising the trip level, installing series compensation on ultra high voltage lines and upgrading various monitoring and operational procedures. Other utilities in North America and Northern Europe and elsewhere implemented programs to reduce the risks associated with geomagnetically induced currents.
Military
One of the few publicly reported military operations impacted was the Australian Army component of the United Nations peacekeeping force which was deployed to Namibia at the time. The storm occurred just as the advance elements of the contingent arrived in Namibia, but the effects were believed to last for weeks afterwards. The Australian contribution to UNTAG was heavily reliant on HF radio communications which were severely impacted.
