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.
Results
Showing 1 to 15 of 15 for “"Paleoclimate reconstructions."”.
-
Paleoclimate reconstructions over the last century from a tropical speleothem on Niue Island, South Pacific
The study examines the question whether speleothems from Niue Island (19°00'S, 169°50'W), a large carbonate platform located at the edge of West Pacific Warm Pool, can serve as archives of hydroclimate controlled by El-Niño/Southern Oscillation (ENSO) and of catastrophic cyclones that frequent the …
-
Functional data methods for climatological processes
… influence of historical proxy observations in paleoclimate reconstructions. Chapter 2 introduces a new class of functional data depths and a rigorous shape outlier detector based on elastic distance. This method handled functional data observed on nonlinear manifolds, such as spheres, which …
-
A 20,000 year flowstone record of Gulf of Mexico sourced moisture in Texas
… for greater spatial coverage of speleothem-based paleoclimate reconstructions when high-quality stalagmite samples are not available.
-
Aridification of the Indian subcontinent during the Holocene : implications for landscape evolution, sedimentation, carbon cycle, and human civilizations
… and identified suitable coring locations for paleoclimate reconstructions. The δ13Cwax record shows a stable arid climate over the dry regions of the Indus plain and a terrestrial biome dominated by C4 vegetation for the last 6,000 years. As the climate became more arid ~4,000 years, sedentary …
-
Evaluating the efficacy of Tridacna derasa and Hippopus hippopus for measuring ENSO signatures in Palau
Tridacna shells are valuable archives in paleoclimate research due to their incremental growth bands, which record environmental conditions such as sea surface temperature (SST) and salinity through variations in oxygen isotopes (δ18O). Their potential for reconstructing past climate variability …
-
Molecular distributions and hydrogen isotopic compositions of n-alkanes from field studies of tree species: applications for paleoclimate studies
… preserved in sediment archives are used as paleoclimate proxies. This use is based on two assumptions, 1) n-alkane δD values are highly correlated with source water δD values (Sachse 2012), and 2) the δD values of n-alkanes within a single site show little variation (Hou 2007). n-alkane …
-
Aridification of the Indian subcontinent during the Holocene : implications for landscape evolution, sedimentation, carbon cycle, and human civilizations
… and identified suitable coring locations for paleoclimate reconstructions. The ([delta]¹³Cwax record shows a stable arid climate over the dry regions of the Indus plain and a terrestrial biome dominated by C₄ vegetation for the last 6,000 years. As the climate became more arid ~4,000 years, …
-
Cave air and dripwater variability in Cathedral Caverns, Alabama
… summer months. These results indicate that the paleoclimate record in Cathedral Cavern’s speleothems and possibly most SE U.S. caves is biased towards a winter climatic signal. This conclusion is supported by: (i) a strong coupling between the timing of karst aquifer recharge (winter) and …
-
Using the growth patterns and geochemistry of coralline red algae to develop proxies for paleoclimate reconstruction in tropical and subarctic environments
… proxy sources for paleoenvironmental and paleoclimate reconstructions. Rhodoliths (Lithothamnion sp.) from the Gulf of Panama (GOP), Panama were grown in a microcosm experiment to evaluate growth patterns and rates. Previous researchers concluded GOP rhodoliths grew annual bands and formed …
-
Clams and climate: implications for measuring seasonality in the marine bivalve, saxidomus gigantea
… climate in this transition is understudied. Few paleoclimate reconstructions are available for the Kodiak archipelago and while climate reconstructions for the Gulf of Alaska are not uncommon, regional climate reconstructions are often insufficient for archaeological research. Many climate …
-
Addressing Water Resource Issues In Barbados Through An Isotopic and Atmospheric Characterization of Precipitation Variability
… meteoric and dripwater in karst environments for paleoclimate reconstructions or aquifer recharge capacity. What is poorly understood is how the isotopic signal of δ<sup>18</sup>O and δ<sup>2</sup>H is transferred through the hydrologic cycle based upon storm type, frequency, intensity, and …
-
Geochemistry of karst deposits in Borneo detailing hydroclimate variations in the Warm Pool across the late Pleistocene
… to increases in anthropogenic greenhouse gases. Paleoclimate reconstructions coupled with model simulations provide insight into the tropical Pacific's role in past climate variability necessary to the development of robust climate projections. Most paleoclimate records, however, still lack the …
-
Seasonality in a changing climate: Insights from the modern ocean with application to the Eocene Epoch
… highlight one of the dominant shortcomings of paleoclimate studies; namely the propensity to express climate variability in terms of global or latitudinal averages, while overlooking local and regional scale climate heterogeneity. Distilling global climate to single numbers (e.g., the …
-
Modeling nonlinear, nonstationary, vector time series : methods and applications.
Methods for modeling nonlinear time series provide ways to extract and describe information from complex and dynamic processes. The class of nonlinear time series models is large. Rather than be exhaustive, we provide a review of two popular classes of nonlinear time series models: Momentum …
-
Subsurface Geophysical Investigations of Oneida Lake Ny: Insights Into Ice Sheet Processes and Deglaciation At Termination I
… Comparing proglacial lake records to other paleoclimate data provides insight into regional climate and ice sheet processes. Therefore, the investigation of a previously glaciated basin may provide information on ice streaming processes, the locations of calving margins, and paleoclimate …