5:15 PM - 7:15 PM
[MIS24-P07] Current Status and Future Prospects of Collecting Old Diaries for Paleoclimate Data Assimilation
Keywords:paleoclimate reconstruction, data assimilation, old diary, socio-hydrology, climate proxy
The objective of this study is to achieve high-resolution paleoclimate reconstruction by combining model simulations and weather records from centuries-old diaries. This approach aims to enhance our understanding on long-term behaviors of extreme events such as floods and droughts and their interaction with human societies. Weather data recorded in these diaries are crucial climate proxies before instrument-based meteorological observations began in Japan. These records offer invaluable insights into meteorological disasters that occurred in the Edo and early Meiji periods.
Traditionally, climate research using historical documents has required the continuity and comprehensiveness of the data, which has limited the selection of sources and constrained the time and area of reconstruction. In contrast, this study employs data assimilation as a reconstruction method, overcoming these limitations and enabling the collection of diverse sources. Besides, this approach allows the reconstruction of not a single meteorological element but rather the comprehensive set of elements calculated by the model.
For this study, we have collected old diaries primarily from Chiba Prefecture, spanning the Edo to early Meiji periods. These include diaries kept by feudal lords, individuals involved with shrines and temples, village heads, and fishing bosses. The wording and detail of weather descriptions vary depending on the author and purpose of the diary. Currently, most of the diaries collected in this study are from the late Edo period, followed by those from the early Meiji period. These historical documents are kept in archives, local museums, boards of education, or by individuals.
We have been systematically researching, collecting, and compiling these records into a database, alongside digitizing originals and facsimiles and gathering reprints. As of February 2025, the collection has over 300 items. The study will continue to expand its collection of old diaries to further refine paleoclimatic reconstructions through data assimilation.
Traditionally, climate research using historical documents has required the continuity and comprehensiveness of the data, which has limited the selection of sources and constrained the time and area of reconstruction. In contrast, this study employs data assimilation as a reconstruction method, overcoming these limitations and enabling the collection of diverse sources. Besides, this approach allows the reconstruction of not a single meteorological element but rather the comprehensive set of elements calculated by the model.
For this study, we have collected old diaries primarily from Chiba Prefecture, spanning the Edo to early Meiji periods. These include diaries kept by feudal lords, individuals involved with shrines and temples, village heads, and fishing bosses. The wording and detail of weather descriptions vary depending on the author and purpose of the diary. Currently, most of the diaries collected in this study are from the late Edo period, followed by those from the early Meiji period. These historical documents are kept in archives, local museums, boards of education, or by individuals.
We have been systematically researching, collecting, and compiling these records into a database, alongside digitizing originals and facsimiles and gathering reprints. As of February 2025, the collection has over 300 items. The study will continue to expand its collection of old diaries to further refine paleoclimatic reconstructions through data assimilation.