[M-IS30_28PO1] 古気候・古海洋変動

[MIS30-P02] インドネシア西ジャワにおける古気候復元のためのスンカイの年輪のδ18Oプロキシの評価

*原田 麻央¹、渡邊 裕美子¹、中塚 武²、田鶴 寿弥子³、堀川 祥生³、バンバン スビヤント⁴、杉山 淳司³、津田 敏隆³、田上 高広¹ (1.京都大学大学院　理学研究科、2.名古屋大学　環境学研究科、3.京都大学　生存圏研究所、4.インドネシア科学院)

キーワード：樹木年輪, セルロース, 安定同位体地球科学, 熱帯, 古気候

We measured annual δ18O variations of two sungkai trees that were collected in the same area as previous study, in order to assess the reproducibility of sungkai δ18O as paleoclimate proxies. Two sungkai δ18O variations has a significant correlation (r = 0.80; P < 0.001) with each other and also with the previous analysis, suggesting that δ18O values of sungkai are affected by external climatic factors. The annual δ18O of SungkaiNAN7 has significant, positive correlations with temperature, sunlight hours and air pressure whereas it has significant, negative correlations with relative humidity and SOI. Moreover, the seasonal δ18O variation acquired during severe drought of 1997-98 El Nino event shows that the maximum δ18O value around 1997 latewood corresponds to rainfall/relative humidity minimum and temperature/sunlight hours/air pressure maximum with a significant time lag.