January 1938 geomagnetic storm

The 25–26 January 1938 geomagnetic storm (also known as the Fátima Storm) was a massive solar storm which occurred 16–26 January with peak activity on 22, 25 and 26 January and was part of the 17th solar cycle. The effects of the storm were extremely limited, the electrification of Europe and North America was still in its infancy.

This storm's great Aurora was witnessed across Europe and had not been seen since 1706. The storm was remarkable primarily because of how far and wide it was observed. Eventually collected reports would show that the Aurora was witnessed in far north of Canada, and spread as far south as southern California and on the Caribbean island Bermuda. In Europe, the Aurora was seen in Northern Scotland, East Austria, in southern Sicily, Gibraltar, Portugal, and news reports in Southern Australia had seen it. All transatlantic radio communication was interrupted and Canada suffered a 12-hour-long short-wave radio blackout. Gathered crowds in the Netherlands were awaiting the imminent birth of Princess Juliana's baby Princess Beatrix who was eventually born on 31 January 1938: the Dutch people cheered the aurora as a lucky omen.

Canada was witness to the most vivid auroral displays in the nights of 24–25 and 25–26 January. The celestial display on 25–26 January was seen from Canada to Bermuda and from Austria to Scotland. In Salzburg, Austria, some residents called on the fire department as they believed something was on fire in their town. So many alarm bells were rung that the fire departments were constantly moving to new alarms while calming the citizens, the deafening sounds of alarm bells further caused panic causing some residents to flee to rural areas. This same alarm was seen in London where many also believed whole streets were on fire, even the guards of Windsor Castle summoned the fire brigade to put out a non-existent fire. In Switzerland, the Swiss Alps peaks covered in white snow were glowing bright and reflecting some of the Auroral rays causing a reflective disco effect. In San Diego, the National Forest Service was called up in the town of Descanso and routed out of bed on 22 January to respond to a 'great fire in the back country', after they checked out the back roads they discovered it was the Crimson Aurora Borealis in the northern sky, which had not been seen in that region since February 1888. In Bermuda, many people believed that a massive freight ship was on fire at sea too far to see with their naked eyes, Steamship captains believed it so much that they checked in with the wireless stations to learn if there were any S.O.S calls and if they could help. In Scotland, many religious people living in the lowlands were afraid and called the Aurora an ill-omen for Scotland.

The electrical side-effects were severely limited only short-wave radio transmissions were shut down for almost 12 hours in Canada. In England where express trains on the Manchester-Sheffield line where the signalling equipment was inoperable due to electrical disturbances. These coal trains who were moving halted and waited at these junctions for safety reasons. Many teletype systems at local Western Union offices were started, spewed out garbage data and suffered electrical shorts.

Due to a particularly thick cloud cover at the beginning of January, only London based Royal Observatory Greenwich was able to observe a large sunspot on 15 January due to a short break in the cloud covers on earth. The latitude of the sunspot was on the +19° N declination on the suns hemisphere, the sunspot at its maximum size covered an area of roughly 3,000 Millionths of the Solar Hemisphere, or 3,000(MSH), the spot resembled a similar spot observed in October 1937. Back then this sunspot became the biggest sunspot observed since records began and trumped the sunspot of the May 1921 geomagnetic storm. The magnetic solar storm was detected on 16 January at around 22:30 GMT by the now defunct Abinger Magnetic Observatory in Surrey, England. A rapid succession of solar flares which created much larger geomagnetic disturbance quickly released towards Earth on 22 January between the hours of 05:00, 09:00 and 10:00, with high frequency, however on 25 January, a day after the massive sunspot had disappeared from direct line of sight over the western side of the Sun, a sudden and rapid barrage of high-frequency waves began at around midday and developed to a new record-breaking highs in the evening. A large movement of the recording magnets at Abinger began at around 17:00 and were extremely noteworthy at 20:00 and 21:30, the geomagnetic disturbance only started calming down at around 03:00 in the morning of 26 January.

The Aurora

The intensely bright arches of crimson light with shifting spectrum of green, blue white and red radiated from a brilliant Auroral Crown near the Zenith instead of appearing as usual in parallel lines. This Aurora was considered by many Catholics to be related to the Fátima Prophecies.

A witness account by Dr. B. A. Keen, former President of the Royal Meteorological Society had written the following during and after seeing the spectacle: "At Harpenden, the display was seen from 18:45 until well after midnight. The early stages appeared as a red glow in the north-west and later in the north-east, with a low broad green arc in between. The area of the luminous sky increased, and by 20:30 the green colour with areas of red extended well south of Orion. Up to 23:00, there seemed to be three periods of brilliant display: the first, and perhaps the best, at 19:45 when a bright red glow in the north-north-east was traversed by many sharply defined green and white shafts, at 20:30 especially in the east; and again at 21:45, when diffuse and rapidly fluctuating green streamers appeared between north-east and north-west, directed towards the Zenith. Thereafter, the luminosity decreased, but as late as 23:00 a broad green arc stretching from north-west to north-east was still clearly visible. About midnight, a fourth display began with red streamers in the north-west, which extended until a broad red band was formed passing through the zenith to the north-east. At 01:00, faint red and green glows were still visible."

See also

• List of solar storms