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Showing 1 to 13 of 13 for “"High-latitude ionosphere"”.
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Transport and energization of heavy ions in earth’s high latitude ionosphere
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms
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Spectral studies of small-scale auroral structure and plasma instability in the high-latitude ionosphere
… been observed by incoherent-scatter radars at high-latitudes. It has been proposed that these radar enhancements result from natural plasma instability, causing the generation of ion-acoustic waves through the decay of unstable Langmuir waves, themselves driven by low-energy electron streams. …
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A 3-D Model of the Auroral Ionosphere
<p>A new 3-D model of the high latitude ionosphere is developed to study the coupling of the ionosphere with the magnetosphere and neutral atmosphere. The model consists of equations describing conservations of mass, momentum and energy for the six ionospheric constituents (O+, NO+, N+2 , O+2 , N+ …
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Reverse Convection Potential Saturation in the Polar Ionosphere
… reverse convection potentials in the day side high latitude ionosphere during periods of steady northward interplanetary magnetic field (IMF) are reported. While it has been shown that the polar cap potential in the ionosphere exhibits non-linear saturation behavior when the IMF becomes …
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Kinetic Modeling of Ionospheric Outflows Observed by the VISIONS-1 Sounding Rocket
<p>Plasma escape from the high-latitude ionosphere (ion outflow) serves as a significant source of heavy plasma to magnetospheric plasma sheet and ring current regions. Outflows alter mass density and reconnection rates, hence global responses of the magnetosphere. The VISIONS-1 (VISualizing Ion …
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Ion-Cyclotron Resonance Heating of O+ in the Topside Ionosphere and Mapping Outflows to the Magnetosphere
… in the turbulent region of the Earth’s topside, high latitude ionosphere. We simulate the impact of this transverse heating process upon energies and velocity distribution functions of outflowing oxygen ions (O+) in the approximate altitude range of 800 km to 15,000 km. To do so most effectively, …
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Sounding rocket measurements of thermal electrons in active nightside aurora
… electrons can carry currents coupling the lower ionosphere and the magnetospheric auroral source. This thesis, focusing on the development and analysis of this new instrument, incorporates the study of two distinct areas. One area is the direct measurement of the ambient thermal electrons which …
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Morphology and dynamics of storm-time ionospheric density structures
… focus on storm-time structuring in the mid- to high latitude ionosphere where large gradients in electron density can cause severe degradation of communication and navigation signals. We begin in Chapter 2 with a review of the primary data sets and methods used to accomplish the collaborative, …
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Non-Linear Magnetosphere-Ionosphere Interactions at High Latitudes
… 3D electromagnetic coupling between the ionosphere and magnetosphere is investigated in this dissertation. The study is based on a non-linear, 3D, reduced magnetohydrodynamic model describing interaction between dispersive Alfven waves and the nightside high-latitude ionosphere. Results …
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Auroral radio absorption : modelling and prediction
… from the solar wind are responsible for enhanced high frequency radiowave absorption in the high latitude ionosphere. Measuring the propagation of radio waves through the ionosphere has been utilised for investigating particle precipitation into the upper atmosphere. Although various methods and …
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Modeling of Polar Cap Ionospheric Patches and Attendant Plasma Instabilities: Initialization from Data and Parametric Analysis
… initial conditions properly replicate polar cap ionosphere configurations at the stage of instability development of interest and the extent to which the model properly captures the relevant theoretical foundation of the plasma dynamics. Within this context then, this research seeks new insights …
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Radio Propagation Through Density Irregularities in the Auroral Ionosphere
… propagating through a structured or turbulent ionosphere undergoes multiple effects, such as refraction, diffraction, etc., that distort the incident radio wave by inducing phase and amplitude fluctuations. These fluctuations are called<em> ionospheric</em><em> scintillation</em>. Scintillation …
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High-Latitude Ionospheric Irregularities Characterized Through Machine Learning Methods
… to understand plasma irregularities in high-latitude regions better. By combining observations and recent findings from modeling, the goal is to identify and classify scintillation signatures caused by different types of irregularities in the ionosphere. The focus is on irregularities …