Homogenization of 19th century meteorological observation data with consideration of daily temperature changes and creation of long-term temperature time series

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K01162
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 04010:Geography-related
• Research Institution: Seikei University
• Principal Investigator: Zaiki Masumi 成蹊大学, 経済学部, 教授 (50534054)
• Co-Investigator(Kenkyū-buntansha): 三上 岳彦 東京都立大学, 都市環境科学研究科, 客員教授 (10114662)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 気温日変化 / 均質化 / 気候変動 / 19世紀 / 気象観測記録 / 日本

Outline of Final Research Achievements

In relation to the inhomogeneity among the data caused by the relocation of meteorological stations, a case study using principal component analysis was conducted for Nagasaki, where the official station was relocated in 1951, to see how the diurnal pattern of temperature varied depending on weather and geographical conditions. The results showed a clear negative correlation between the diurnal temperature range and cloud cover. Statistical analysis was also conducted using data obtained from continuous meteorological observations at several locations in Hakodate to classify the diurnal patterns of temperature. The above study revealed the possibility of correcting the discontinuity of temperature data for observations under certain conditions (altitude difference and sea level difference below a certain level).

Free Research Field

気候学

Academic Significance and Societal Importance of the Research Achievements

本研究は，これまで本課題に関連する研究者らが収集してきた19世紀の日本の気象観測データと，20世紀以降を中心とした気象庁の気象データを連結する際に問題となるデータ間の不均質性について，特に気温の日平均値を均質化する手法を確立することを目指してきた．その結果，①気温の日変化パターンをいくつかに類型化し，それを特徴づける気象や地理的条件を明らかにすること，そして類型化されたパターンごとに②気温の日平均値の均質化が可能であること，を明らかにした．19世紀から現代まで連続する均質な日気温データが整備されれば，気温極値の出現頻度や変化傾向がより長期にわたって検討可能となり，気候変動の特徴解明につながる．