[S-GL17] Geochronology and Isotope Geology

[SGL17-P01] Evaluating the dendroclimatological potential of tree-ring intra-annual oxygen isotopic ratios

*Yumiko Watanabe¹, Zhen Li², Takeshi Nakatsuka² (1.Department of Earth and Planetary Scineces, Kyoto University, 2.Graduate School of Enviromental Studies, nviromental Studies, Nagoya University)

Keywords:tree ring, isotope, proxy

Dendroclimatological studies have been conducted extensively in the Asian monsoon region and thus precipitation variabilities has been reconstructed based on interannual cellulose oxygen isotopic ratios. While previous studies have mainly reported annual isotopic data, intra-annual isotopic data is needed to understand rainfall history with higher time-resolution. Therefore, this study aimed to assess the hydrological potential of tree-ring intra-annual oxygen isotopic ratios.

We analyzed intra-annual oxygen isotopic ratios over the last 100 years on Japanese cedar collected from Ashiu, northeastern Kyoto and compared them with meteorological data. The results show that precipitation can be reconstructed with higher time-resolution by dividing annual rings into six segments. In particular, it was possible to distinguish between precipitation during the rainy season and the typhoon season at the end of summer.