Amazing Aurora During the IGY:
The Great Magnetic Storm of February 1958
The International Geophysical Year, an eighteenth-month period between July 1, 1957, and the end of 1958, was a program of worldwide scientific cooperation with the goal of learning more about the physics of the Earth. These months were chosen because of their position during a maximum of the sunspot cycle, when solar activity, auroral displays, and other events would also be at a maximum. None of the planners of the IGY, however, knew that one of the biggest geomagnetic storms in history would occur right in the middle of the program. From February 9-12, 1958, the Sun-Earth system was seized by an extraordinary event of "space weather" -- and the IGY meant that ground observations from around the world could be coordinated as never before with the brand-new science of satellites.
Around Earth, conditions were calm until 8:26 on the night of the tenth, when huge
magnetic disturbances were recorded around the globe. Plots of the
horizontal component of Earthís magnetic field at Fredericksburg, Virginia,
first deviated from their lines
by one hundred gammas, or one-five-hundredth of the normal field strength.
Then, at 8:59, the trace needle in Fairbanks jumped several thousand gammas.
Also, the Dst index swung off course significantly. (Dst is based on an average of
magnetic field observations near the equator -- during geomagnetic storms,
the magnetic field there drops off sharply as the energy content of the electrical
"ring current" around the equator rises. See
Dst Index.) The figure below shows a plot
of Dst data from February 1958, with a huge downward spike beginning
at one in the morning (EST) February 11. "Extreme"
conditions are in effect when the Dst index drops below -100; this
February storm caused the Dst to fall to -425.
Four hours later, around one in the morning, the Fredericksburg trace settled down a bit from its wild fluctuations. At this time, unusual conditions were observed by alert IGY scientists. Instruments on a balloon sent up by a University of Minnesota team observed bursts of X-rays from the aurora beginning at 1:22 AM EST. Antennas in Boulder picked up a marked decrease in radio noise coming from the stars. At 10:00 AM, Fredericksburg observers stated the storm had mostly passed; it was declared over 24 hours later.
Not just a pleasant red glow indicated the silent magnetic disturbance, however. The storm also interrupted communications all over. Radio waves, normally bounced off a quiet ionosphere to their targets, were being absorbed in a disturbed one. At 9:00 PM on February 10, all direct radio circuits lost contact with Europe; AT&T could transmit through South America until 9:45, while RCA passed messages through Tangier and Surinam until 11:00. For an hour and a half after 11:00, the radio blackout was complete. Western Union telegraph cables across the North Atlantic suffered serious interruptions from 9:01 until about 10:00. At 9:02, the North Atlantic became a 2650-volt battery, as a surge along the Bell System telephone cable from Newfoundland to Scotland turned eastbound voices into whispers. In Boston that night, two television stations swapped signals, flipping channels for viewers. Air-to-ground communication was disrupted for airplanes, forcing pilots to use each other as relay stations; one Air Force plane near the South Pole had to make much of its flight over frigid waters with no radio contact of any kind. Power difficulties, however, were minor: only Toronto fell briefly into darkness as Ontario's circuit breakers tripped.
Although most communications were badly crippled for a few hours during the storm, some ham radio operators heard much better transmissions than normal. Ham radio signals normally go straight through the ionosphere, but can bounce off during magnetic storms, allowing operators to speak to others far beyond the normal fifty-mile radius. On February 10, a northern Virginia radio picked up operators from Mississippi and Iowa, and one in Mississippi heard Rhode Island.
The magnetic storm of February 10-12, 1958, is unique as a true "storm for the people." The scientific observations made of flares and magnetic fields were nothing particularly new, but the IGY instigated coordinated data collection at an unprecedented level (even without a Special World Interval) and commanded the media coverage that could raise public awareness that magnetic storms existed. Also "for the people" was the widespread red aurora of the event, since people who did not live in the Arctic could finally see the striking phenomenon.
Quotes and Anecdotes:
[February 9, 1958] 4:08 PM -- Class 2+ flare begins on Sun in sunspot region ABOO 4:12 PM -- Solar radio bursts begin 4:40 PM -- Maximum of the flare 6:02 PM -- End of the flare [February 10, 1958] 8:26 PM -- Time of storm onset, magnetic fluctuation begins 8:30 PM -- Minor disruption of AT&T and New York Times North Atlantic radio communications; New York Times loses contact with overseas stations 9:00 PM -- Aurora appears in New York City 9:01 PM -- Western Union begins to experience serious telegraph interruptions 9:02 PM -- North Atlantic "battery" created by major currents flowing across ocean; telephone problems ensue 9:45 PM -- AT&T loses contact with South America 10:00 PM -- RCA loses contact with Tangier 11:00 PM -- An hour-and-a-half long radio blackout begins [February 11, 1958] 1:30 AM -- Lowell Observatory observes peak auroral activity 10:00 AM -- Fredericksburg magnetic observatory says the major magnetic activity is over [February 12, 1958] 10:00 AM -- Magnetic storm declared over by the Coast and Geodetic SurveyUseful Sources:
A Japanese newspaper reporting the sighting of a red aurora.
Red aurora, as observed by Bert Vorchheimer on February 10, 1958.