Scholarship & Research
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Item Statistical properties of separators in model active regions(Montana State University - Bozeman, College of Letters & Science, 1998) Welsch, Brian ThomasItem Analysis and critique of the envelope-tracing method for the investigation of solar prominences(Montana State University - Bozeman, College of Letters & Science, 1953) Cape, John AnthonyItem The solar extreme ultra-violet corona : resolved loops and the unresolved active region corona(Montana State University - Bozeman, College of Letters & Science, 2005) Cirtain, Jonathan Wesley; Chairperson, Graduate Committee: Dana W. LongcopeIn this work, physical characteristics of the solar corona as observed in the Extreme Ultra-Violet (EUV) regime are investigated. The focus will be the regions of intense EUV radiation generally found near the locations of sunspots. These regions are commonly called active regions. Multiple space-based observing platforms have been deployed in the last decade; it is possible to use several of these observatories in combination to develop a more complete picture of the solar corona. Joint Observing Program 146 was created to collect spectroscopic intensities using the Coronal Diagnostic Spectrometer on Solar and Heliospheric Observatory and EUV images using NASA's Transition Region and Coronal Explorer. The emission line intensities are analyzed to develop an understanding of the temperature and density of the active region coronal plasma. However, the performance of the CDS instrument in the spatial and temporal domains is limited and to compensate for these limitations, data collected by the TRACE instrument provide a high spatial and temporal resolution set of observations. One of the most exciting unsolved problems in solar astrophysics is to understand why the corona maintains a temperature roughly two orders of magnitude higher than the underlying material. A detailed investigation of the coronal emission has provided constraints on models of the heating mechanism, since the temperature density and evolution of emission rates for multiple ionic species are indicative of the mechanism(s) working to heat the corona. The corona appears to consist of multiple unresolved structures as well as resolved active region structures, called coronal loops. The purpose of the present work is to determine the characteristics of the unresolved background corona. Using the characterizations of the coronal unresolved background, results for loops after background subtraction are also presented. This work demonstrates the magnitude of the unresolved coronal emission with respect to the total emission along the line of sight, and the relationship of the coronal background emission to the resolved loop emission. It is apparent from this analysis that the unresolved corona is the dominant source of radiation in active regions. Additionally, the unresolved active region coronal emission can be characterized by hydrostatic scaling laws.Item Modeling the temporal and spatial variability of solar radiation(Montana State University - Bozeman, College of Agriculture, 2012) Mullen, Randall Scott; Chairperson, Graduate Committee: Lucy Marshall; Brian L. McGlynn (co-chair); Brian L. McGlynn and Lucy A. Marshall were co-authors of the article, 'Use of intensity- duration- frequency curves and exceedance- frequency curves for quantifying solar radiation variability' in the journal 'Renewable energy' which is contained within this thesis.; Brian L. McGlynn and Lucy A. Marshall were co-authors of the article, 'A beta regression model to obtain interpretable parameters and estimates of error for improved solar radiation predictions' in the journal 'Journal of applied meteorology and climatology' which is contained within this thesis.; Brian L. McGlynn and Lucy A. Marshall were co-authors of the article, 'Modeling solar radiation using the spatial auto-correlation of the daily fraction of clear sky transmissivity' in the journal 'Theoretical and applied climatology' which is contained within this thesis.; Brian L. McGlynn and Lucy A. Marshall were co-authors of the article, 'Evaluating a beta regression approach for estimating fraction of clear sky transmissivity in mountainous terrain' in the journal 'Hydrology and earth system sciences' which is contained within this thesis.Solar radiation is fundamental to ecological processes and energy production. Despite growing networks of meteorological stations, the spatial and temporal variability of solar radiation remains poorly characterized. Many solar radiation models have been proposed to enhance predictions in areas without measurement instrumentation. However, these models do not fully take advantage of the increasing number of data collection sites, nor are they expandable to incorporate additional metrological information when available. In this dissertation we: 1) developed a method of statistical analysis to summarize and communicate solar radiation reliability, 2) applied a beta regression model to leverage auxiliary meteorological information for enhanced solar radiation prediction, 3) refined the beta regression model and considered spatial auto-correlation to better predict solar radiation across space, 4) extended and evaluated these methods in a mountainous region. These advancements in the characterization and prediction of solar radiation are detailed in the following chapters of this dissertation.