Aurorae seen on Earth are the end of a complex process that begins with a violent, dynamic process deep within the sun’s interior.
However, studying the depths of the sun is no easy task, even for scientists. The best they can do is to observe the surface using space-based telescopes. One problem that scientists are attempting to solve is how a super-geomagnetic storm on Earth comes to being. These geomagnetic storms find their roots in sunspots, that are acne-like depressions on the sun’s surface. As the sun approaches the peak of its 11-year solar cycle, these sunspots, numbering in the hundreds, occasionally release all that stored magnetic energy into deep space, in the form of coronal mass ejections (CMEs) (which are hot wisps of gas superheated to thousands of degrees).
Super-geomagnetic storms, a particularly worse form of geomagnetic storm, can induce power surges in our infrastructure, causing power outages that can plunge the world into darkness, and can cause irreversible damages to our infrastructure
If the earth lies in the path of an oncoming CME, the energy release from their resultant magnetic field alignment can cause intense geomagnetic storms and aurorae on Earth.
This phenomenon, which is astrophysical and also electromagnetic in nature, can have serious repercussions for our modern technological society.
Super-geomagnetic storms, a particularly worse form of geomagnetic storm, can induce power surges in our infrastructure, causing power outages that can plunge the world into darkness, and can cause irreversible damages to our infrastructure. The last recorded super-geomagnetic storm event occurred more than 150 years ago. Known as the Carrington event, the storm destroyed telegraph lines across North America and Europe in 1859. The risk for a Carrington-class event to happen again was estimated to be 1 in 500-years, which is quite low, but based on limited data. Ramifications are extremely dangerous if it were to ever happen.
However, in the past decade, it was learnt that such super-geomagnetic storms are much more common than scientists had figured. To top it all, it wasn’t just science, but it was a valuable contribution by art – specifically ancient Japanese and Chinese historical records that shaped our modern understanding of super-geomagnetic storms.
Ryuho Kataoka, a Japanese space physicist, played a seminal role in searching for evidence of super-geomagnetic storms in the past using historical methods. He is presently an associate professor in physics, holding positions at Japan’s National Institute of Polar Research, and The Graduate University for Advanced Studies.
“There is no modern digital dataset to identify extreme space weather events, particularly super-geomagnetic storms,” said Professor Kataoka. “If you have good enough data, we can input them into supercomputers to do physics-based simulation.”
However, sunspot records go until the late 18th century when sunspots were actively being cataloged. In an effort to fill the data gap, Professor Kataoka decided to be at the helm of a very new but promising interdisciplinary field combining the arts with space physics. “The data is limited by at least 50 years,” said Professor Kataoka. “So we decided to search for these red vapor events in Japanese history, and see the occurrence patterns … and if we are lucky enough, we can see detailed features in these lights, pictures or drawings.” Until the summer of 2015, Ryuho Kataoka wasn’t aware of how vast ancient Japanese and Chinese history records really were.
“There is no modern digital dataset to identify extreme space weather events, particularly super-geomagnetic storms,” said Professor Kataoka.
In the past 7 years, he’s researched a very specific red aurora, in documents extending to more than 1400 years. “Usually, auroras are known for their green colors – but during the geomagnetic storm, the situation is very different,” he said. “Red is of course unusual, but we can only see red during a powerful geomagnetic storm, especially in lower latitudes. From a scientific perspective, it’s a very reasonable way to search for red signs in historical documents.”
A vast part of these historical red aurora studies that Professor Kataoka researched came from literature explored in the last decade by the AURORA-4D collaboration. “The project title included “4D”, because we wanted to access records dating back 400 years back during the Edo period,” said Professor Kataoka.
“From the paintings, we can identify the latitude of the aurora, and calculate the magnitude or amplitude of the geomagnetic storm.” Clearly, paintings in the Edo period influenced Professor Kataoka’s line of research, for a copy of the fan-shaped red aurora painting from the manuscript Seikai (which translates to ‘stars’) hangs on the window behind his office desk at the National Institute of Polar Research.
The painting fascinated Professor Kataoka, since it depicted an aurora that originated during a super-geomagnetic storm over Kyoto in 1770. However, the painting did surprise him at first, since he wondered whether the radial patterns in the painting were real, or a mere artistic touch to make it look fierier. “That painting was special because this was the most detailed painting preserved in Japan,” remarked Professor Kataoka. “I took two years to study this, thinking this appearance was silly as an aurorae scientist. But when I calculated the field pattern from Kyoto towards the North, it was actually correct!”
Fan-shaped red aurora painting from the ‘Seikai’, dated 17th September, 1770; Picture Courtesy: Matsusaka City, Mie Prefecture.
The possibility to examine and verify historical accounts using science is also a useful incentive for scholars of Japanese literature and scientists partaking in the research.
“This is important because, if we scientists look at the real National Treasure with our eyes, we really know these sightings recorded were real,” said Professor Kataoka. “The internet is really bad for a survey because it can easily be very fake,” he said laughing. It’s not just the nature in which science was used to examine art – to examine Japanese “national treasures” that is undoubtedly appealing, but historical accounts themselves have contributed to scientific research directly.
“From our studies, we can say that the Carrington class events are more frequent than we previously expected,” said Professor Kataoka. There was a sense of pride in him as he said this. “This Carrington event is not a 1 in 200-year event, but as frequent as 1 in 100 years.” Given how electricity is the lifeblood of the 21st century, these heightened odds do ingrain a rather dystopian society in the future, that is ravaged by a super-geomagnetic storm.
Professor Kataoka’s work has found attention within the space physics community. Jonathon Eastwood, Professor of Physics at Imperial College London said to EdPublica, “The idea to use historical information and art like this is very inventive because these events are so rare and so don’t exist as information in the standard scientific record.”
There’s no physical harm from a geomagnetic storm, but the threat to global power supply and electronics is being increasingly recognized by world governments. The UK, for instance, identified “space weather” as a natural hazard in its 2011 National Risk Register. In the years that followed, the government set up a space weather division in the Met Office, the UK’s foremost weather forecasting authority, to monitor and track occurrences of these coronal mass ejections. However, these forecasts, which often supplement American predictions – namely the National Oceanic and Atmospheric Administration (NOAA) – have failed to specify previously where a magnetic storm could brew on Earth, or predict whether a coronal mass ejection would ever actually strike the Earth.
Professor Kataoka said he wishes space physicists from other countries participate in similar interdisciplinary collaborations to explore their native culture’s historical records for red aurora sightings
The former occurred during the evacuation process for Hurricane Irma in 2017, when amateur radio ham operators experienced the effects of a radio blackout when a magnetic storm affected the communications network across the Caribbean. The latter occurred on another occasion when a rocket launch for SpaceX’s Starlink communication satellites was disrupted by a mild geomagnetic storm, costing SpaceX a loss of over $40 million.
Professor Kataoka said he wishes space physicists from other countries participate in similar interdisciplinary collaborations to explore their native culture’s historical records for red aurora sightings. He said the greatest limitation of the AURORA-4D collaboration was the lack of historical records from other parts of the world. China apparently boasts a history of aurora records longer than Japan, with a history lasting before Christ himself. “Being Japanese, I’m not familiar with British, Finnish or Vietnamese cultures,” said Professor Kataoka. “But every country has literature researchers and scientists who can easily collaborate and perform interdisciplinary research.” And by doing so, it’s not just science which benefits from it, but so is ancient art whose beauty and relevance gains longevity.