Japanese scientists have explained the nature of atmospheric phenomena that arose over the territory of medieval China and Japan in the X-XIII centuries. The reason turned out to be powerful geomagnetic storms that arose due to strong flares on the Sun. An article by scientists was published in Space Weather magazine, briefly told by the Gizmodo edition.
The earliest known evidence of phenomena presumably accompanying geomagnetic storms is a description by the Japanese poet Fujiwara Teika, dated February 21-23, 1204. He reported that mysterious "red and white vapors" appeared in the sky, which, according to experts, are the aurora borealis. At the same time, the Chinese observed a large number of sunspots, which indicates an increased activity of the Sun. Researchers checked if similar references are found in earlier historical documents.
Scientists have found that auroras were also observed in China and Japan during the Song Empire (960-1279). Many of the atmospheric phenomena were repeated with an interval of 27 days, which corresponds to the period of the Sun's revolution around its axis. At the same time, radiocarbon analysis of tree rings showed that the peak of their activity occurs at solar maxima.
The researchers concluded that the auroras recorded in Asia about a thousand years ago are associated with powerful multiple coronal mass ejections from the same region of the Sun. According to experts, such geomagnetic storms can now lead to power outages, which happened, for example, during the Carrington Event in 1859. Then in the United States and Europe telegraphs went out of order, and auroras were observed all over the world.