| Descript |
192 p |
| Note |
Source: Dissertation Abstracts International, Volume: 70-08, Section: B, page: 4715 |
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Thesis (Ph.D.)--Brown University, 2009 |
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This work makes use of newly available, high-resolution, quantitative sea surface temperature (SST) records to make the first detailed inter-comparison of the temperature histories of different areas of the tropical ocean over the course of Plio-Pleistocene climate evolution. The secular and spectral evolution of sea surface temperatures is largely identical in the tropical upwelling zones of the eastern equatorial Pacific, eastern equatorial Atlantic and Arabian Sea. Coupling among tropical SSTs and between tropical SSTs and high latitude climate strengthened significantly at ∼2.7 Ma, coincident with the intensification of northern hemisphere glaciation. Intra-tropical climate synchronization and coupling between low and high latitude climates on glacial-interglacial timescales likely involved strong greenhouse gas feedbacks as well as changes in meridional heat transport. While sensitive to high latitude climate change, the tropics may also exert an important influence on high latitudes climate dynamics. An amplified temperature response to obliquity forcing in the eastern equatorial Pacific just prior to the intensification of northern hemisphere glaciation may have sufficiently reduced heat transport to North America to allow for the build-up of large ice sheets during obliquity lows. The tropical SST response also leads and is coherent with the oxygen isotope record in the 400 kyr band, suggesting channeling of a precession-related temperature response from the tropics to the high latitudes, likely through a combination of meridional heat transport and water vapor feedbacks |
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This work also opens new possibilities for the application of the alkenone SST proxy, through validation of alkenone SST estimates from marine strata exposed on land. Alkenone SST estimates generated from an outcrop of Plio-Pleistocene marine marls uplifted in southern Italy faithfully replicate alkenone SST estimates from co-eval seafloor sediments in the nearby Ionian Basin. This result is promising for future alkenone SST reconstructions from additional land sections exposed throughout the Mediterranean |
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School code: 0024 |
| Host Item |
Dissertation Abstracts International 70-08B
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| Subject |
Geology
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Physical Oceanography
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0372
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0415
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| Alt Author |
Brown University
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