[M-IS24] History X Earth and Planetary Science

[MIS24-09] Records of aurora by the participants of Japanese Embassy to the United States in 1860

*Harufumi Tamazawa¹ (1.Institute of Industrial Science, the University of Tokyo)

Keywords:Historical document, Aurora

The Man'en Gannen Embassy to America was a mission sent by the Edo Shogunate to America in 1860 for the purpose of exchanging ratification documents for the Treaty of Amity and Commerce between the United States and Japan. Some of participant left a record, which is an important collection of records in modern Japanese history. On March 29, 1860, the group witnessed an aurora on the way to San Francisco, and their efforts to confirm what this unfamiliar phenomenon was are recorded written by Kimura Tetsuta, Tamamushi Sadayu, Sano Kanae, and so on. These are also records of the voyage, with detailed information on time and location. Hirose Yasuan's "Circumnavigation of the Sea Diary" includes a diagram of the streaky structure that appears to spread out like a fan. All of the records refer to the aurora as "Hokko" (northern light) and instead of using terms such as "Sekki" (red vaper) derived from Chinese literature, they use the terminology used in the translations of European specialist books that had been imported at the time, which shows part of the process of the terminology becoming established during this period. The year 1860 was the maximum of the 10th solar cycle and was also the year after the so-called Carrington Event of 1859, a time when the aurora was easy to see. These are useful records that provide descriptions in addition to time and position information from navigation records.