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.
The Science of the Storm:
The magnetic storm event of February 10-12, 1958, came into being because of a
solar flare on February 9. At the Sacramento
Peak Observatory in Sunspot, New Mexico, an observer saw a "sudden, explosive
brightness in an area that a second before had been dark and cloudy."
Sacramento Peak classified the flare, which showed itself between 4:08 and 6:02 PM
(Eastern Standard Time), as 2+. Just minutes after the flare began, high-frequency
receivers on Earth began to pick up the radio bursts characteristic of big solar flares;
in this case, they were classified as "Magnitude Major Plus" by the Harvard
Radio Astronomy Station in Fort Davis, Texas.
Although an IGY Special World Interval was not declared at this point
(experts figured it was not major enough), the observations at Earth a day
and a half later would put scientists around the world on alert.
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
A Storm for the People:
The storm that roared
in on the night of February 10 surprised and delighted some and inconvenienced others.
Wonderful once-in-a-lifetime observations of the aurora borealis were made by
many. On that night, the aurora showed its rarest fiery red, frightening many people
that sudden fires had begun. Not only did the aurora borealis form in a color
not seen very often, but also its range extended from the small oval in the Arctic to
a much wider area, enveloping much of the Northern Hemisphere in northern lights.
The aurora was suddenly seen in Havana, Los Angeles, Washington, New York,
and even from the S.S. President Taylor, off the coast of Mexico only
eighteen degrees above the equator. The New York aurora appeared about
9:00 PM, reached maximum intensity within the hour, shifted from red to green, and
then increased in intensity again around 11:30. Observers in the San Joaquin Valley
in California saw a red aurora between 9:50 PM and 2:40 AM EST.
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