Assessment of sungkai tree-ring delta O-18 proxy for paleoclimate reconstruction in western Java, Indonesia

摘要

To assess the reproducibility of sungkai delta O-18 as paleoclimate proxies, we measured annual delta O-18 variations of two sungkai trees that had been collected in the same area as in a previous study. Two sungkai delta O-18 variations showed significant mutual correlation (r = 0.80; P < 0.001) and correlation with results of earlier analyses, suggesting that external climatic factors affect the delta O-18 values of sungkai. The annual delta O-18 of SungkaiNAN7 shows significant, positive correlation with temperature, sunlight hours, and air pressure. It shows significant, negative correlation with relative humidity and SOI. Moreover, the seasonal delta O-18 variation acquired during severe drought of the 1997-1998 El Nino event shows that the maximum delta O-18 value around 1997 latewood corresponds to the rainfall/relative humidity minimum and corresponds to the temperature/sunlight hours/air pressure maximum with a considerable time lag. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.