Browsing by Author "Kilper, Gary K."

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    Mass composition and dynamics in quiet sun prominences
    (2009) Kilper, Gary K.; Alexander, David
    Solar prominences are transient phenomena in the solar atmosphere that display highly dynamic activity and can result in dramatic eruptions, ejecting a large amount of material into the heliosphere. The dynamics of the prominence plasma reveal information about its interaction with the magnetic field of the prominence, while the eruptions are associated with coronal mass ejections, which greatly affect space weather near Earth and throughout the solar system. My research on these topics was conducted via observational analyses of the partially-ionized prominence material, its composition, and the dynamics over time in prominences that range in activity from quiescent to highly active. The main results are evidence that (1) in quiescent prominences, neutral He is located more in the lower part of the structure, (2) a higher level of activity in prominences is related to a mixing of the material, and (3) an extended period of high activity and mixing occurs prior to eruptions, possibly due to mass loading. In addition, innovative modifications to analytical techniques led to measurements of the material's mass, composition, and small-scale dynamics.
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    Observational analysis of the compositional variation in solar filaments
    (2007) Kilper, Gary K.; Alexander, David
    Solar filaments have long been associated with coronal mass ejections and Space Weather phenomena. Filaments are dynamcal, and changes in their overall mass or its distribution could trigger an eruption. However, a comprehensive study of the elemental composition, abundance, and dynamics in a variety of filaments had not yet been conducted. The research work presented here is a detailed study of twenty filaments with various properties, which was conducted by analyzing the absorption due to the filaments in cotemporal He I (10830 A) and Haalpha (6563 A) images. The results show bands of relative helium deficits and surpluses that imply a stratification of filament material, possibly due to neutral atom cross-field diffusion. For more highly-varying material; there is a weak direct relation between a change in absorption and a change in the relative abundance of helium, and erupting filaments exhibit increasing absorption and a spatial homogenization of material in the pre-erupting filament section.