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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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Hines, Sophia Katharine Vizza. |
Glacial-interglacial cycles, occurring at a period of approximately 100,000 years, have dominated Earth's climate over the past 800,000 years. These cycles involve major changes in land ice, global sea level, ocean circulation, and the carbon cycle. While it is generally agreed that the ultimate driver of global climate is changes in insolation, glacial cycles do not look like insolation forcing. Notably, there is a highly non-linear warming response at 100,000 years to a relatively small forcing, implicating a more complicated system of biogeochemical and physical drivers. The ocean plays a pivotal role in glacial-interglacial climate through direct equator-to-pole transport of heat and its role in the carbon cycle. The deep ocean contains 60 times more... |
Tipo: Text |
Palavras-chave: Paleoceanography; Oceanography; Climate change; Glacial cycles; Ocean circulation; Ocean dynamics. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00493/60447/63892.pdf |
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