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The Study Of Ionospheric Response To Precipitation Using Sounding Rocket Observations, Ian James Cohen
The Study Of Ionospheric Response To Precipitation Using Sounding Rocket Observations, Ian James Cohen
Doctoral Dissertations
Understanding the role that the ionosphere plays in phenomena such as the development of auroral arcs and ion outflow is basic to the investigation of these processes and critical to the advancement of the broader study of magnetosphere-ionosphere coupling. Sounding rockets present an optimal platform for such studies, allowing low-cost access to altitudes that are difficult to reach by other means. Additionally, these measurements are key to validating current models and furthering understanding of the near-Earth space environment. This thesis highlights two particular rocket-borne instruments that measure electron populations in the ionosphere: the Electron Retarding Potential Analyzer (ERPA) and the …
Distinct Types Of Electron Distributions Functions In Magnetotail Reconnection: Implications For Particle Energization, Guanlai Li
Doctoral Dissertations
Magnetic reconnection converts energy stored in magnetic fields to plasma kinetic energy by accelerating and heating the plasma, and is believed to be the underlying mechanism of many energetic phenomena in space. Electron distribution functions exhibit the effects of electron energization by the reconnection process. Using CLUSTER data, we have studied electron distributions in the inflow and outflow regions of magnetotail reconnection. Based on comparisons of CLUSTER measurements with PIC simulation results, we discuss the energization mechanisms. The inflow electron distributions can be characterized by their temperature anisotropy into three distinct categories: (1) anisotropic with Tepara>Teperp, (2) isotropic with …
The Relationship Between Oceanic Transform Fault Segmentation, Seismicity, And Thermal Structure, Monica Wolfson Schwehr
The Relationship Between Oceanic Transform Fault Segmentation, Seismicity, And Thermal Structure, Monica Wolfson Schwehr
Doctoral Dissertations
Mid-ocean ridge transform faults (RTFs) are typically viewed as geometrically simple, with fault lengths readily constrained by the ridge-transform intersections. This relative simplicity, combined with well-constrained slip rates, make them an ideal environment for studying strike-slip earthquake behavior. As the resolution of available bathymetric data over oceanic transform faults continues to improve, however, it is being revealed that the geometry and structure of these faults can be complex, including such features as intra-transform pull-apart basins, intra-transform spreading centers, and cross-transform ridges. To better determine the resolution of structural complexity on RTFs, as well as the prevalence of RTF segmentation, fault …
Porous Medium Convection At Large Rayleigh Number: Studies Of Coherent Structure, Transport, And Reduced Dynamics, Baole Wen
Doctoral Dissertations
Buoyancy-driven convection in fluid-saturated porous media is a key environmental and technological process, with applications ranging from carbon dioxide storage in terrestrial aquifers to the design of compact heat exchangers. Porous medium convection is also a paradigm for forced-dissipative infinite-dimensional dynamical systems, exhibiting spatiotemporally chaotic dynamics if not ``true" turbulence. The objective of this dissertation research is to quantitatively characterize the dynamics and heat transport in two-dimensional horizontal and inclined porous medium convection between isothermal plane parallel boundaries at asymptotically large values of the Rayleigh number $Ra$ by investigating the emergent, quasi-coherent flow. This investigation employs a complement of direct …