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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
Multi-Periodic Climate Dynamics: Spectral Analysis Of Instrumental, Short- And Long-Length Proxy Temperature Records, Michael David Madsen
Multi-Periodic Climate Dynamics: Spectral Analysis Of Instrumental, Short- And Long-Length Proxy Temperature Records, Michael David Madsen
Theses and Dissertations
Analyzing 26 short-length (less than 3000 years) instrumental and proxy temperature records and five long-length (greater than 3000 years) proxy temperature records using Discrete Fourier Transform has shown that as the length of significant periods increase in the time domain then so does the power at which the period is observed. A t-test verifies that a positive correlation exist between the length of the significant periods and the power with a confidence level of ∝ >0.05. Significant frequencies with period greater than 30 years are confirmed using Monte Carlo simulations, which were created using a nonlinear approach known as fractional …
Northern Hemisphere Sea Level Pressure Synchronization And Its Effect On Northern Hemisphere Temperature Variability, Joshua Daniel Verbeten
Northern Hemisphere Sea Level Pressure Synchronization And Its Effect On Northern Hemisphere Temperature Variability, Joshua Daniel Verbeten
Theses and Dissertations
We consider monthly anomalies of zonally averaged sea level pressure (SLP) in the Northern Hemisphere (NH) from two reanalysis products. A measure of synchronization utilizing correlation coefficient in a five-year sliding window across all latitude pairs is computed over this data. It is found that there have been two NH SLP synchronization episodes since the 1890s, which are significant to approximately three standard deviations. Similar statistically significant synchronization events are seen in simulations of 42 global climate models (GCM) with the dominant synchronization pattern in GCMs proving dynamically consistent with observations. Furthermore, a GCM-based NH temperature anomaly composite shows a …
Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park
Impacts Of Spatial, Environmental, And Compositional Differences On Community-Level Flowering Phenology, Isaac William Park
Theses and Dissertations
This dissertation investigates three important topics related to flowering phenology throughout the United States. First, this work evaluates the utility of herbarium records for estimating historical variation in community-level flowering phenology, and evaluate the relationship of such estimates to satellite-derived greenup timing at regional scales. This dissertation then reconstructs historical variations in flowering phenology throughout the spring, summer, and autumn across South Carolina for the years 1951 through 2009. These estimates will then be compared to seasonal temperature variations throughout this period. Finally, this dissertation develops novel herbarium-based methods to separate intraspecific phenological variations over space from changes in flowering …