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| Jian, Zhimin; Wang, Yue; Dang, Haowen; Lea, David W.; Liu, Zhengyu; Jin, Haiyan; Yin, Yaqian. |
| The El Niño−Southern Oscillation (ENSO), which is tightly coupled to the equatorial thermocline in the Pacific, is the dominant source of interannual climate variability, but its long-term evolution in response to climate change remains highly uncertain. This study uses Mg/Ca in planktonic foraminiferal shells to reconstruct sea surface and thermocline water temperatures (SST and TWT) for the past 142 ky in a western equatorial Pacific (WEP) core MD01-2386. Unlike the dominant 100-ky glacial−interglacial cycle recorded by SST and δ18O, which echoes the pattern seen in other WEP sites, the upper ocean thermal gradient shows a clear half-precessional (9.4 ky or 12.7 ky) cycle as indicated by the reconstructed and simulated temperature (ΔT) and δ18O... |
| Tipo: Text |
Palavras-chave: Thermocline temperature; Half-precession; Western equatorial Pacific; Meridional gradient. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72647/71649.pdf |
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| Shakun, Jeremy D.; Raymo, Maureen E.; Lea, David W.. |
| Early Pleistocene glacial cycles in marine O-18 exhibit strong obliquity pacing, but there is a perplexing lack of precession variability despite its important influence on summer insolation intensity - the presumed forcing of ice sheet growth and decay according to the Milankovitch hypothesis. This puzzle has been explained in two ways: Northern Hemisphere ice sheets instead respond to insolation integrated over the summer, which is mostly controlled by obliquity, or anti-phased precession-driven variability in ice volume between the hemispheres cancels out in global O-18, leaving the in-phase obliquity signal to dominate. We evaluated these ideas by reconstructing Laurentide Ice Sheet (LIS) meltwater discharge to the Gulf of Mexico from 2.55-1.70Ma using... |
| Tipo: Text |
Palavras-chave: Glacial cycles; Milankovitch hypothesis; Laurentide Ice Sheet; Gulf of Mexico; Early Pleistocene. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53233/54774.pdf |
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