20 Undergraduate and Graduate Geoscience Student Showcase (Posters)

Friday, 17 March 2023
1:30 PM - 5:30 PM
Grand Ballroom A–D

ANNUALLY-RESOLVED ENSO-HYDROCLIMATE ACTIVITIES AS RECORDED IN STABLE OXYGEN ISOTOPE OF TECTONA GRANDIS L. F. FROM SOUTHEAST SULAWESI OVER THE PAST ~300 YEARS

Paper number: 20-23
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

El Niño-Southern Oscillation (ENSO) is a quasi-periodic interannual oscillation of the ocean-atmosphere system in the tropical Pacific which greatly influences global climate variability. However, until recently the long-term response to external radiative forcings is still controversial. In this study, we observed oxygen isotopes from dendrochronologically dated teak (Tectona grandis L. f.) α-cellulose samples collected at Muna, Indonesia (5.3ºS, 123ºE, elev. 10m). In this study we managed to combine four crossdated increment core samples of tg01c (1712 - 1995), mun63 (1799 -2004), tg11a (1680 - 1848), and mun81 (1764 - 2004) into an annually composite time series with a span of the past ~300 years. In processing this time series composite, we performed low-pass filtering by applying the Singular Spectrum Analysis (SSA) algorithm with five embedding dimensions to obtain ENSO-hydroclimate information which is the interannual mode by removing the main embedding dimension. The annually-resolved composite time series of δ18O that we constructed has a higher resolution than other studies that have been conducted to reconstruct ENSO-hydroclimate activities in the western tropical Pacific region over this period. This annually-resolved composite time series of δ18O can be used to study the response of ENSO to volcanic and greenhouse gas forcings in the period before and after the industrial revolution.

Geological Society of America Abstracts with Programs. Vol. 55, No. 2

doi: 10.1130/abs/2023SE-385637

© Copyright 2023 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.