Recovery of tropical cyclone activity around Japan from the foreign ship logs during Edo era

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K20328
• Project/Area Number (Other): 18H05307 (2018-2019)
• Research Category: Grant-in-Aid for Challenging Research (Pioneering)
• Allocation Type: Multi-year Fund (2020); Single-year Grants (2018-2019)
• Review Section: Medium-sized Section 4:Geography, cultural anthropology, folklore, and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Kubota Hisayuki 北海道大学, 理学研究院, 特任准教授 (40359211)
• Co-Investigator(Kenkyū-buntansha): 財城 真寿美 成蹊大学, 経済学部, 教授 (50534054) ; 塚原 東吾 神戸大学, 国際文化学研究科, 教授 (80266353)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: データレスキュー / 航海日誌 / 台風 / 江戸時代 / 外国船

Outline of Final Research Achievements

We focused on ship log weather records on vessels sailing through Japanese waters from the late 18th century. Tropical cyclone (TC) track was identified by Perry's fleet by US Naval Japan Expedition near Okinawa in July 1853. Another TC track was found during the bombardment of Kagoshima by UK Navy ships in August 1863. TC landfall in Japan was recovered using a combination of TC track data and meteorological data observed at weather stations and lighthouses from 1877 to 2023. We identified lower annual TC landfall numbers during the 1970s to the 2000s and found other periods have more TC landfall numbers including the nineteenth century. No trend in TC landfall number was detected associated with global warming.

Free Research Field

気象学

Academic Significance and Societal Importance of the Research Achievements

江戸時代に日本では気象測器を用いた観測がほとんど行われていなかったため、気象測器を積んだ外国船が日本近海に数多く航行していたことに着目し、海外の図書館に所蔵されている航海日誌を収集し、デジタル化した気象データを利用するという、全く新しい発想に基づいて江戸時代の台風を明らかにした研究意義は大きい。現在直面している地球温暖化や気候変動を明らかにするには過去の気象データが欠かせない。日本の気候を調べるにも国際的な協力体制が重要であることを本研究課題は示している。