Climate variability over the past 100 years in Myanmar derived from tree-ring stable oxygen isotope variations in Teak

Abstract

© 2019, Springer-Verlag GmbH Austria, part of Springer Nature. We present a 100-year oxygen isotope record from teak tree-ring cellulose (δ18O), originating from a site in southern Myanmar that preserves the isotopic ratios of the regional wet season’s rainfall. Tree-ring δ18O correlates strongly with regional rainfall during the months of May to October (r = − 0.353, p < 0.01). We found the tree-ring δ18O had clear signals of the June to September Indian Summer Monsoon (ISM) over the years 1948–1998 (r = − 0.53, p < 0.01). The δ18O has a significant and negative correlation with the minimum temperature in September and has a significant positive correlation with maximum temperature in November and December. The study found that δ18O has a significant positive correlation with the difference between the maximum temperature and the minimum temperature (DTR) in August to October. Based on our results, it can be concluded that tree-ring δ18O in teak in southern Myanmar is controlled by the amount of rainfall during the monsoon season and the temperature in the November and December. Spatial correlation and spectral analyses revealed a strong impact of the El Niño-Southern Oscillation (ENSO) on tree-ring δ18O of teak. In addition, tree-ring δ18O also captures the signal of the Indian Ocean Dipole (IOD).