The three-day May 1921 geomagnetic storm, also known as the New York Railroad Storm, was caused by the impact of an extraordinarily powerful
coronal mass ejection
A coronal mass ejection (CME) is a significant release of plasma and accompanying magnetic field from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accept ...
on
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
's
magnetosphere. It occurred on 13–15 May as part of
solar cycle 15
Solar cycle 15 was the fifteenth solar cycle since 1755, when extensive recording of solar sunspot activity began. The solar cycle lasted 10.1 years, beginning in July 1913 and ending in August 1923. The maximum smoothed sunspot number observed dur ...
, and was the most intense geomagnetic storm of the 20th century.
Since it occurred before the extensive interconnectivity of electrical systems and the general electrical dependence of infrastructure in the developed world, its effect was restricted; however, its ground currents were up to an order of magnitude greater than those of the
March 1989 geomagnetic storm
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 Hydr ...
which interrupted electrical service to large parts of northeastern North America.
Effects
The storm's electrical current sparked a number of fires worldwide, including one near
Grand Central Terminal which made it known as the "New York Railroad Storm".
Contemporary scientists estimated the size of the
sunspot (AR1842)
which began on May 10th—and caused the storm—as .
The storm was extensively reported in
New York City
New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the Un ...
, which was a center of telegraph activity as a railroad hub.
Aurora
An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of bri ...
s ("northern lights") appeared throughout the eastern
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, creating brightly-lit night skies.
Telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...
service in the U.S. first slowed and then virtually stopped at about midnight on 14 May due to blown fuses and damaged equipment. Radio propagation was enhanced during the storm due to ionosphere involvement, however, enabling unusually good long-distance reception. Electric lights were not noticeably affected.
Undersea telegraph cables were affected by the storm. Damage to telegraph systems was also reported in Europe
and the
Southern Hemisphere.
2021 study estimated
Dst
Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typicall ...
m of -533 nT.
See also
*
Active region
An active region is a temporary region in the Sun's atmosphere characterized by a strong and complex magnetic field. They are often associated with sunspots and are commonly the source of violent eruptions such as coronal mass ejections and solar ...
*
Geomagnetic storm
A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth's magnetic field.
The disturbance that d ...
*
List of solar storms
Solar storms of different types are caused by disturbances on the Sun, most often from coronal mass ejections (CMEs) and solar flares from active regions, or, less often, from coronal holes. Minor to active solar storms (i.e. storming restricted ...
References
Footnotes
Bibliography
*The Aurora Borealis of May 14, 1921
* A bibliography of newspaper and journal articles.
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
*
*
{{Solar storms
1921 in science
1921 natural disasters
Geomagnetic storms
1921 natural disasters in the United States
May 1921 events