Oxygen isotopic measurements from Holcene of sediment core MD02-2529, tropical pacific, supplement to: Leduc, Guillaume; Vidal, Laurence; Cartapanis, Olivier; Bard, Edouard (2009): Modes of eastern equatorial Pacific thermocline variability: Implications for ENSO dynamics over the last glacial period. Paleoceanography, 24(3), PA3202

Changes in El Niño-Southern Oscillation (ENSO) variability are difficult to extract from paleoceanographic reconstructions because they are superimposed on changes in seasonal variability that modulate the first-order climate signal. Here we address this problem by reconstructing thermocline structu...

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Bibliographic Details
Main Authors: Leduc, Guillaume, Vidal, Laurence, Cartapanis, Olivier, Bard, Edouard
Format: Dataset
Language:English
Published: PANGAEA - Data Publisher for Earth & Environmental Science 2009
Subjects:
DEPTH, sediment/rock
AGE
Neogloboquadrina dutertrei, δ18O
Giant piston corer
Isotope ratio mass spectrometry
MD126
Marion Dufresne 1995
International Marine Global Change Study IMAGES
Guillaume
Pacific
Planktonic foraminifera
Online Access:https://dx.doi.org/10.1594/pangaea.759995
https://doi.pangaea.de/10.1594/PANGAEA.759995
Description
Summary:Changes in El Niño-Southern Oscillation (ENSO) variability are difficult to extract from paleoceanographic reconstructions because they are superimposed on changes in seasonal variability that modulate the first-order climate signal. Here we address this problem by reconstructing thermocline structure from a marine sediment core retrieved from the eastern equatorial Pacific. At the core location, changes in hydrologic parameters within the thermocline are linked to ENSO activity, with a reduced influence of seasonal variability compared to surface waters. We performed repeated isotopic analyses (d18O) on single specimens of the thermocline-dwelling planktonic foraminifera Neogloboquadrina dutertrei at several targeted time periods over the last 50 ka to extract the total thermocline variance, a parameter supposed to reveal changes in ENSO. No fundamental changes in amplitude and frequency of the events were detected despite differences in climatic background. However, our data suggest that long-term variations in the thermocline variability occurred over the last 50 ka, with the highest and lowest ENSO activities occurring during the last glacial period and the Last Glacial Maximum, respectively.

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