Researchers Back Record of Red Aurora in Thirteenth-Century Kyoto (News)
Tokyo, April 4 (Jiji Press)—To see an aurora is almost impossible in Kyoto in the present day, but it was possible in the low-latitude Japanese city in the early thirteenth century, as recorded by poet Fujiwara no Sadaie (1162–1241), according to a recent study by a Japanese research team.
In his diary titled Meigetsuki (Record of the Brilliant Moon), the poet, also known as Teika, wrote that he witnessed sekki (red air) on February 21 and 23, 1204. This is the earliest known example of prolonged aurora sightings in Japan.
Based on the descriptions, a joint team with members from the National Institute of Polar Research and the National Institute of Japanese Literature worked on the hypothesis that a solar flare occurred at that time, followed by related phenomena.
When high-energy particles discharged from a solar flare reach Earth, a magnetic storm occurs, producing an aurora as a result. This can generally be viewed only in high-latitude areas near the magnetic poles, but when the solar activity is particularly strong, auroras can be viewed over much more of the globe.
The team found that Chinese text Song shi (a history of the Song dynasty, lasting from 960 to 1279) includes observation records dated February 21, 1204, of a huge sunspot, which suggests a high level of solar activity and repeated occurrences of large magnetic storms.
Deputy Director Terashima Tsuneyo of the National Institute of Japanese Literature, a member of the joint team, notes: “Teika’s description of the event in his diary is exceptionally precise, pointing to his multiple talents in both literary and scientific spheres.”
[Copyright The Jiji Press, Ltd. Content edited by the Nippon.com editorial team.]