Precipitation changes in the western tropical Pacific over the past millennium

Geology
Julian P. Sachs
By:  and 

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Abstract

Modern seasonal and inter-annual precipitation variability in Palau is linked to both meridional movement of the Intertropical Convergence Zone (ITCZ) and changes in the Pacific Walker Circula- tion (PWC) associated with the El Niño–Southern Oscillation. Thus, Palau’s hydroclimate should be sensitive to mean shifts in the ITCZ and PWC on decadal to centennial time scales. Using compound- specific hydrogen isotope ratios (δ2H) of dinosterol in lake sediments, we generated a decadal-resolution proxy record of hydroclimatic variability in Palau spanning the past 800 yr. Results indicate a dry- ing trend during the Little Ice Age in Palau, consistent with a south- ward displacement of the ITCZ. In addition to the secular drying trend, there are persistent large (~20‰) multi-decadal to centennial oscillations in the δ2H record, the most recent of which indicates an abrupt shift to drier conditions in the mid-1970s that coincides with a decadal-scale negative shift in the Southern Oscillation Index.

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Publication type Article
Publication Subtype Journal Article
Title Precipitation changes in the western tropical Pacific over the past millennium
Series title Geology
DOI 10.1130/G37822.1
Volume 8
Issue 44
Year Published 2016
Language English
Publisher Geological Society of America
Contributing office(s) St. Petersburg Coastal and Marine Science Center
Description 4 p.
First page 671
Last page 674
Country Palau
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