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dc.contributor.authorFurtado, Jason C.en_US
dc.date.accessioned2011-03-04T21:18:05Z
dc.date.available2011-03-04T21:18:05Z
dc.date.issued2010-11-11en_US
dc.identifier.urihttp://hdl.handle.net/1853/37302
dc.description.abstractTropical and extratropical Pacific decadal climate variability substantially impact physical and biological systems in the Pacific Ocean and strongly influence global climate through teleconnection patterns. Current understanding of Pacific decadal climate variability centers around the El Niño-Southern Oscillation (ENSO), the Aleutian Low (AL), and the Pacific Decadal Oscillation (PDO). However, recent literature has highlighted the emerging roles of secondary modes of variability of the tropical and extratropical Pacific atmosphere and ocean in global climate change: the Central Pacific Warming (CPW) phenomenon, the North Pacific Oscillation (NPO), and the North Pacific Gyre Oscillation (NPGO). This work analyzes the statistics and uncertainties behind Pacific interannual and decadal-scale climate variability, and focuses on better understanding the roles of the CPW, NPO, and NPGO in the climate system. The study begins by examining the dynamics of the NPO and its role in Pacific interannual and decadal climate variability. Results illustrate that the individual poles of the NPO have relations at high frequencies, but only the southern node contains a deterministic low-frequency component, which is forced by tropical Pacific sea surface temperature (SST) variability, as shown with a modeling experiment. The NPO-induced variability by the tropical Pacific SST is then integrated by the underlying ocean surface to form the decadal-scale NPGO signal. Thus, a new link between the CPW, the NPO, and the NPGO is formed, expanding the current framework of Pacific decadal variability and its implications for weather and climate. The new framework of North Pacific decadal variability (NPDV) is then evaluated in 24 state-of-the-art coupled climate models. Results indicate that the models in general have difficulty reproducing the leading modes of NPDV in space and time, particularly the NPGO mode and its connection to the NPO. Furthermore, most models lack the proper connections between extratropical and tropical Pacific, for both the ENSO/AL/PDO and CPW/NPO/NPGO connections. Improvements in these teleconnections are thus needed to increase confidence in future climate projections. The last part of the dissertation explores further the importance of the CPW mode by comparing and contrasting two popular paleoclimate SST anomaly reconstruction methods used for tropical Indo-Pacific SSTs. The first method exploits the high correlation between the canonical ENSO mode and tropical precipitation; the second method uses a multi-regression model that exploits the multiple modes of covariability between tropical precipitation and SSTs, including the CPW mode. The multi-regression approach demonstrates higher skill throughout the tropical Indo-Pacific than the first approach, illustrating the importance of including the CPW phenomenon in understanding past climates.en_US
dc.publisherGeorgia Institute of Technologyen_US
dc.subjectNorth Pacificen_US
dc.subjectAtmospheric circulationen_US
dc.subjectCoupled climate modelsen_US
dc.subjectIPCCen_US
dc.subjectNorth Pacific oscillationen_US
dc.subjectTropical Pacificen_US
dc.subjectClimate changeen_US
dc.subjectENSOen_US
dc.subject.lcshClimatology
dc.subject.lcshClimatic changes
dc.subject.lcshTropospheric circulation
dc.titleOn the uncertainties and dynamics of Pacific interannual and decadal climate variability and climate changeen_US
dc.typeDissertationen_US
dc.description.degreePh.D.en_US
dc.contributor.departmentEarth and Atmospheric Sciencesen_US
dc.description.advisorCommittee Chair: Di Lorenzo, Emanuele; Committee Member: Anderson, Bruce T.; Committee Member: Black, Robert X.; Committee Member: Cobb, Kim M.; Committee Member: Webster, Peter J.en_US


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