NOAA/WDS Paleoclimatology - Tono, Central Japan 6-Divided Intra-Annual Tree Ring Oxygen Isotope Data from 1609-2020 CE

Oxygen isotope ratios (d18O) of tree-ring cellulose and historical documentary records are widely used to explore the hydroclimatic conditions of the past. In this study, we attempted to reconstruct chronologies of local climate disasters spanning 4 centuries in central Japan using these proxy data. For tree-ring d18O measurements, we prepared cellulose samples from a long-living cedar tree with continuously broad ring widths. To enhance the temporal resolution, we divided each annual ring into several (mainly six) segments. Analysis of the correlations with observed relative humidity and precipitation data revealed that the intra-ring d18O variations in the sample tree reflected the hydroclimatic conditions from April to July in each year. Subsequently, we chronologically listed the occurrence of eight types of disasters in the 17th to 19th centuries in the area adjacent to the sample tree according to 20 titles of “Town/City history”, which is a compilation of historical documentary records from the local municipality. By comparison with the intra-ring d18O data, we found that most of the major droughts and long rains recorded in the historical documents occurred in the Baiu rainy season (typically June–July) or pre-Baiu season, corresponding to the growing season of the sample tree. Based on an analysis of the intra-ring d18O variation for documentary-based drought and long-rain years, we set thresholds of intra-ring d18O values to identify and extract drought and long-rain years. Drought and long-rain chronologies obtained by applying these thresholds were temporally continuous, complementing those based on documentary records. They depicted the relationships between the frequency of these climate disasters and the occurrence of major famines and the long-term tendency of length and magnitude of the Baiu rainy season in historical times.

本存档古气候学（Paleoclimatology）研究数据集可从隶属于世界古气候学数据服务（World Data Service for Paleoclimatology, WDS）的美国国家海洋和大气管理局国家环境信息中心（National Centers for Environmental Information, NCEI）获取。该数据集对应的NCEI研究类型为树木年轮（Tree Ring）。数据集涵盖树木年轮相关参数，采集区域位于东亚日本境内。其时间覆盖范围为以距今（Before Present, BP）为基准的日历纪年体系下的341年至-60年。如需了解参数及研究区域的详细信息，请查阅元数据（metadata）说明。使用该数据集时，请引用本研究。