[M-IS23] [JJ] Paleoclimatology and paleoceanography

[MIS23-10] Climate variations in northern Japan as reconstructed from tree ring cellulose δ¹⁸O

★Invited papers

*Akane Tsushima¹, Masaki Sano¹, Takeshi Nakatsuka¹, Zhen Li¹, Motonari Ohyama², Koh Yasue³ (1.Research Institute for Humanity and Nature, 2.Botanical Gardens, Tohoku University, 3.Shinshu University )

Keywords:Tree-ring cellulose δ18O, Japan

Tree-ring cellulose δ¹⁸O is known to be a promising proxy for reconstructing hydroclimate variations in monsoon Asia because the δ¹⁸O is not controlled by ecological factors but by two climatic parameters (i.e., relative humidity and δ¹⁸O of precipitation). In this study, two tree-ring δ¹⁸O series were developed by measuring two individual trees (Cryptomeria japonica) growing in Miyagi, northern Japan. Climatic response analyses reveal that the relationship between tree-ring δ¹⁸O and relative humidity is not temporally stable. Also, the tree-ring δ¹⁸O from Miyagi shows complex correlations with other tree-ring δ¹⁸O from Japan, indicating that tree-ring δ¹⁸O in northern Japan is not simply controlled by local hydroclimate. Continued effort toward the development of a dense tree-ring network will shed more light on variability of climate in Japan.