Intensity and impact of the New York Railroad superstorm of May 1921

Space Weather
By: , and 



Analysis is made of low‐latitude ground‐based magnetometer data recording the magnetic superstorm of May 1921. By inference, the storm was driven by a series of interplanetary coronal mass ejections, one of which produced a maximum pressure on the magnetopause of ~64.5 nPa, sufficient to compress the subsolar magnetopause radius to ~5.3 Earth radii. Over the course of the storm, low‐latitude geomagnetic disturbance exhibited extreme local time (longitude) asymmetry that can be attributed to substorm disturbance extending to low latitudes. The storm attained an estimated maximum −Dst on 15 May of 907 ± 132 nT, an intensity comparable to that of the Carrington event of 1859. The May 1921 storm brought spectacular aurorae to the nighttime sky. It also interfered with and damaged telephone and telegraph systems associated with railroad systems in New York City and State. These later effects were due to a combination of three factors: the localized details of geomagnetic vector disturbance, the geographic expression of the Earth's surface impedance tensor, and the configurations and physical parameters of the electrical networks of the day.

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Publication type Article
Publication Subtype Journal Article
Title Intensity and impact of the New York Railroad superstorm of May 1921
Series title Space Weather
DOI 10.1029/2019SW002250
Volume 17
Issue 8
Year Published 2019
Language English
Publisher AGU
Contributing office(s) Geologic Hazards Science Center
Description 12 p.
First page 1281
Last page 1292
Country United States
State New York
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