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Twentieth century sea surface temperature and salinity variations at Timor inferred from paired coral δ 18 O and Sr/Ca measurements
Author(s) -
Cahyarini Sri Yudawati,
Pfeiffer Miriam,
Nurhati Intan Suci,
Aldrian Edvin,
Dullo WolfChristian,
Hetzinger Steffen
Publication year - 2014
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2013jc009594
Subject(s) - sea surface temperature , indian ocean dipole , throughflow , climatology , coral , oceanography , western hemisphere warm pool , sss* , geology , advection , pacific decadal oscillation , proxy (statistics) , indo pacific , environmental science , mathematical optimization , ecology , physics , mathematics , machine learning , biology , computer science , soil science , thermodynamics
Abstract The Indonesian Throughflow (ITF), which represents the global ocean circulation connecting the Pacific Warm Pool to the Indian Ocean, strongly influences the Indo‐Pacific climate. ITF monitoring since the late 1990s using mooring buoys have provided insights on seasonal and interannual time scales. However, the absence of longer records limits our perspective on its evolution over the past century. Here, we present sea surface temperature (SST) and salinity (SSS) proxy records from Timor Island located at the ITF exit passage via paired coral δ 18 O and Sr/Ca measurements spanning the period 1914–2004. These high‐resolution proxy based climate data of the last century highlights improvements and cautions when interpreting paleoclimate records of the Indonesian region. If the seasonality of SST and SSS is not perfectly in phase, the application of coral Sr/Ca thermometry improves SST reconstructions compared to estimates based on coral δ 18 O only. Our records also underline the importance of ocean advection besides rainfall on local SSS in the region. Although the El Niño/Southern Oscillation (ENSO) causes larger anomalies relative to the Indian Ocean Dipole (IOD), Timor coral‐based SST and SSS records robustly correlate with IOD on interannual time scales, whereas ENSO only modifies Timor SST. Similarly, Timor SST and SSS are strongly linked to Indian Ocean decadal‐scale variations that appear to lead Timor oceanographic conditions by about 1.6–2 years. Our study sheds new light on the complex signatures of Indo‐Pacific climate modes on SST and SSS dynamics of the ITF.