Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"Orbital Forcing"”.
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The Effect of Orbital Forcing on the MJO’s Amplitude and Phase Speed
… represents the MJO, by changing Earth's orbital parameters. In response to the orbital forcing, boreal winter mean precipitation increases, consistent with a stronger Hadley circulation, and the mean lower-tropospheric westerly winds shift southward over the Indo-Pacific warm pool. The …
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Orbital Forcing of Late Miocene-Pleistocene Environmental Change in the Zhada Basin, SW Tibetan Plateau
… a clipped response to summer insolation forcing, which has been shown to be largely an eccentricity-modulated precession signal.
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Cyclostratigraphy And Sedimentation Of The Cenomanian-Turonian Tuscaloosa Marine Shale
… of the Tuscaloosa Marine Shale to determine if orbital forcing is apparent in mineralogical data suites. Geochemical data suites obtained via x-ray diffraction from five cored wells located near the southern Mississippi/Louisiana border were used in the study. The results were used in concert …
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Depth and orbital tuning : a new chronology of glaciation and nonlinear orbital climate change
It is suggested that orbital tuning casts a false light upon the chronology of glaciation and the understanding of the climatic response to orbital variations. By developing a new age-model, independent of orbital assumptions, a significant non-linear response to orbital forcing becomes evident in …
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On the origins of the ice ages : insolation forcing, age models, and nonlinear climate change
… thesis revolves about the relationship between orbital forcing and climate variability. To place paleo and modern climate variability in context, the spectrum of temperature variability is estimated from time-scales of months to hundreds of thou- sands of years using a patchwork of proxy and …
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Correlation and Causes of Fifth Order Cycles Within the Upper Cretaceous Eagle Formation, Bighorn Basin of Wyoming
… which in marine settings has been attributed to orbital forcing (Milankovitch cyclicity). A series of 19 sections were measured through the Virgelle Member of the Eagle Formation. Most were measured on the “J”-shaped escarpment that constitutes the nose and north flank of the Thermopolis …
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Speleothem climate capture of the Neanderthal demise
… the record which is interpreted as a response to orbital-forcing. Sub-orbital climate instability was superimposed onto this long-term trend as evidenced through wet-dry proxies (δ18O, δ13C, Mg and Sr). Millennial-scale events coincident with the timing of North Atlantic Heinrich Events have been …
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The Evolution of the El Niño-Southern Oscillation and Tropical Pacific Climate Across the Last Deglaciation
… 25,000 years. I speculate that a combination of orbital forcing, changes in upper ocean thermal stratification, trade wind strength, and the mean position of the Intertropical Convergence Zone (ITCZ) acted to suppress past ENSO variability. These results emphasize the dynamic relationship between …
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Holocene variations in summer temperature and effective moisture: Understanding the causes of vegetational dynamics in Alaska
… midge assemblage analysis, to test the role of orbital forcing and moisture balance on interior Alaskan vegetation assemblages. The results presented here provide some of the first high-resolution, vegetation-independent climate records from Alaska that span the entire Holocene and highlight …
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The role of biosphere-atmosphere-ocean interactions in the climate of West Africa during the Middle Holocene
… been developed and validated based on current forcings over the region of West Africa. Here, we use ZonalBAM to study the response of the coupled biosphere-atmosphere system to changes in the Earth's orbital forcing during the Middle Holocene (6K yrs BP) and the relative contribution of …
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Environmental change recorded in physical and geochemical proxies over the Last Glacial Cycle from two Northland, New Zealand dune lakes: Lake Kanono and Lake Kai Iwi
… results indicate periodicities associated with orbital forcing, solar cycles, and CO2 outgassing from upwelling in the Southern Ocean manifested as changes in intensity and position of the SWW.
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Glacial-Interglacial Variability of Eastern Pacific Hydroclimate
… ka) periods to investigate the effects of orbital forcing (insolation), greenhouse gases, and ice sheets on moisture source, precipitation seasonality and geographic patterns of rainfall variability across SWNA. This research fills a critical data gap and ultimately provides a mechanistic …
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East African monsoon variability since the last glacial
… the complex interactions between long-term orbital forcing, atmosphere, ocean and land surface conditions. My findings help to understand how abrupt climate changes occur and how these changes correlate with climate changes elsewhere on Earth.
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Reconstruction of environmental and climate dynamics using multi-proxy evidence from palaeosols of the Western Cape, South Africa
… by major tectonic changes, local variations in orbital forcing, better known as Milankovitch cycles, and its position at the interface between temperate and tropical circulation systems. Regrettably, a dearth of reliable and continuous palaeoenvironmental records means that relatively little is …
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Rates and dates: Evaluating rhythmicity and cyclicity in sedimentary and biomineral records
… examines the methods by which extrabasinal orbital forcing (i.e. Milankovitch cycles) can be tested in the rock record. In order to distinguish these patterns, computer generated carbonate rock records were simulated with the resulting outcrops tested using common methods. These simulations …
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Travertine from Egypt's Western Desert: a terrestrial record of North African paleohydrology and paleoclimate during the late Pleistocene
… on travertine's association with glacial forcings should be scrutinized. In summary, our study reveals that travertine deposition in broadly synchronous regional episodes across the Western Desert is consistent with the pluvial events recognized in marine records. Subject to further …
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Holocene climate and environmental variability in NE Germany inferred from annually laminated lake sediments
… to gradual changes in Northern Hemisphere orbital forcing, which induced colder and windier conditions in Central Europe and, therefore, reinforced lake circulation. Decadal to centennial scale periods of increased lake circulation coincide with settlement phases at Lake Tiefer See, as …