Japan Geoscience Union Meeting 2016

Presentation information


Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS17] Paleoclimatology and paleoceanography

Tue. May 24, 2016 9:00 AM - 10:30 AM A04 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Tomohisa Irino(Faculty of Environmental Earth Science, Hokkaido University), Minoru Ikehara(Center for Advanced Marine Core Research, Kochi University), Akira Oka(Atmosphere and Ocean Research Institute, The University of Tokyo), Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University), Ikuko Kitaba(Research Centre for Palaleoclimatology, Ritsumeikan University), Akihisa Kitamura(Institute of Geosciences, Faculty of Science, Shizuoka University), Masaki Sano(Research Institute for Humanity and Nature), Ryuji Tada(Department of Earth and Planetary Science, Graduate School of Science, The Univeristy of Tokyo), Takeshi Nakagawa(Ritsumeikan University), Akira Hayashida(Department of Environmental Systems Science, Doshisha University), Chair:Akira Hayashida(Department of Environmental Systems Science, Doshisha University)

9:15 AM - 9:30 AM

[MIS17-14] Accuracy evaluation of climatic reconstruction with historical daily weather record using old diaries written in the observation period

*Kenjiro Sho1, Kaoru Kamatani2, Junpei Hirano3 (1.Nagoya Institute of Technology, 2.Research Institute for Humanity and Nature, 3.Teikyo University)

Keywords:historical daily weather record, accuracy evaluation, observation period

Weather records of old diaries are useful source for climate reconstruction in historical times in Japan. Those records have been compiled for since the 11th century for the capital (Kyoto) area, and are widely available for since the 18th century for most part of Japan. Although daily weather records have an advantage of accessibility and high temporal resolution, their description is qualitative and dependent on subjectivity of the author, and therefore evaluation of their accuracy is necessary for reconstructing long-term climatic variation by compiling historical weather records together with modern observed meteorological data. In this study we collected several types of historical daily weather records including private diaries of merchants and scholars and official dairies of temples written in the late 19th to early 20th centuries that parallel meteorological observational records. By comparing weather records with observed data on the daily basis, we found weather descriptions of “light rain”, “rain” and “heavy rain” correspond to a broad range of daily precipitation without distinct boundaries and about one fourth of rainy days are missed in weather record of diaries. Referring to plural diaries and using climatic indices derived by accumulating weather descriptions for months or seasons (such as number of rainy days) is essential to enhance reliability and objectivity of climate reconstruction using such subjective and qualitative information. On the other hand, sharp boundary was found between daily temperatures corresponding to weather descriptions “rain” and “snow”, which implies rain/snow ratio is a promising proxy for winter temperature in the central part of Japan.