In order to trace the secular variation of the geomagnetic field in historic time, the documents of ancient aurorae can be utilized. In China, Korea and Japan, there are a number of valuable records, which can be reasonably supposed to describe the events of auroral appearance. After a comparison of these descriptions with those in Europe, the archaeo-secular variation in the geomagnetic field can be inferred. A preliminary examination of the aurora! appearance on the same day in the Occident and Orient suggests that the geomagnetic dipole axis might have been inclined towards China around 11-12th centuries AD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.