Description
- Abstract:
- Continental climate experiences significant changes and severely affects human's life. Quantitative reconstruction of past continental climate changes is extremely important for understanding their mechanisms in order to predict future climate changes. In this thesis, I have developed new proxies for continental precipitation isotopic ratios, which is one of the most quantitative and effective proxies for continental climate changes, and proxies for mean annual surface air temperature from lake sediments. Calibration using transects of 33 modern lake surface sediments in the southwest United States demonstrated that hydrogen isotopic ratios (D/H) of leaf waxes produced by terrestrial plants and preserved in lake sediment are a reliable proxy for continental precipitation isotopic ratios. The effect of relative humidity is countered by the opposing effect of vegetation changes. D/H ratios of C22 n-alkanoic acid and sediment bound C16 n-alkanoic acid capture past temperature changes based on transects of modern lake sediments in eastern North America. I have reconstructed temperature variability during the late Pleistocene to the early Holocene in northeastern North America (New England). The records from Blood Pond and Rocky Pond, Massachusetts revealed well-known climate shifts during the late Pleistocene, similar to the Greenland ice core records. The centennial-scale temperature variability was most likely related to solar activity based on the spectral analysis. The records during the early Holocene revealed a prominent and abrupt climate reversal (~3 degree cooler than the millennial-scale background) between 9.3 and 9.1 kyr BP, stronger than the climate reversal at 8.4 kyr BP (associated with the Greenland 8.2 ka event). The stronger climate response at the 9.2 ka event than 8.4 ka event could be attributed to the geographic distribution of Laurentide Ice Sheet and associated atmospheric circulation during the early Holocene.
- Notes:
- Thesis (Ph.D.) -- Brown University (2009)
Access Conditions
- Rights
- In Copyright
- Restrictions on Use
- Collection is open for research.
Citation
Hou, Juzhi,
"Calibration and application of lipid H isotopic ratios for Quantitative Reconstruction of New England Climate Variability over the past 15 kyr"
(2008).
Earth, Environmental and Planetary Sciences Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z037770Z
Relations
Collection:
-
Earth, Environmental and Planetary Sciences Theses and Dissertations
Theses and Dissertations for the Earth, Environmental and Planetary Sciences department....