Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"exosphere"”.
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Escape of hydrogen from the exosphere of Mars
… of exploration, the martian neutral hydrogen exosphere has remained poorly characterized. The first measurements of this layer by Mariner 6 and 7 revealed it to be optically thick in Lyman α emission, along with a characteristic temperature that was higher than the majority of the collisional …
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Quantification of the spatial structure and temporal variability of Earth's exosphere using optical tomography
Knowledge of the spatial structure of Earth's exosphere, the outermost atmospheric layer, is crucial for understanding various aspects of aeronomy and heliophysics, such as atmospheric chemistry and energetics, magnetospheric energy dissipation, ion-neutral coupling, and atmospheric evolution. …
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The Lunar Exosphere: Spatial and Temporal Variations of Sodium and Potassium Emissions from November 2013 to May 2014
… resolution spectroscopy to investigate the lunar exosphere by measuring sodium and potassium spectral line profiles to determine spatial and temporal variations in exospheric effective temperatures and velocities. Observations were made from the National Solar Observatory (MMP) at Kitt Peak, …
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Setting Constraints on the Lunar Exosphere: A Comprehensive Analysis of Velocity Resolved Sodium and Potassium Line Profile Measurements
… study the morphology and dynamics of the lunar exosphere. Additionally, potassium D1 (7698.9646 Å) is used as a complement to sodium. The two species approach, with sodium being the main attraction, provides constraints on the critical drivers of the lunar exosphere. Observations were made at …
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Evolution of the Geohydrologic Cycle During the Past 700 Million Years
… of the Earth. The near-surface hydrosphere (exosphere) includes the atmosphere, cryosphere (glacial and polar ice), the biosphere, surface water, groundwater, and the oceans. The amounts of water in these various reservoirs of the hydrologic cycle have likely varied significantly over the …
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An experimental approach to thermal and solar weathering of Mercury's crust
… have the potential to contribute sodium to the exosphere, but in order to to produce potassium from the surface, more potassium rich felspars may be necessary. Calcium and magnesium are released from diopside clinopyroxene while enstatite orthopyroxene is relatively unaffected by weathering. …
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Study of the Martian upper atmosphere using radio tracking data
… structure from the middle atmosphere up to the exosphere is studied using radio tracking data from the Mars Odyssey and the Mars Reconnaissance Orbiter spacecraft. Measurements in the Martian middle atmosphere, near 100 -- 110 km, are obtained from the aerobraking phase of the Mars Odyssey …
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Density Model Corrections Derived from Orbit Data to Characterize Upper Atmospheric Density Variations
… of density variations in the thermosphere and exosphere. This research primarily focuses on using SLR data. This examination will give a better idea of obtainable improvements in atmospheric density. Consideration will also be given to the effects of varying levels of geomagnetic and solar …
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Helium resonance fluorescence LiDAR
… helium content in the thermosphere and exosphere (within 250 km-750 km), where helium (23S) is most abundant. Strategies have been employed to increase the output power of the He Li- DAR transmitter using fiber amplifier technology, increase the light gathering power of the receiver, and …
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Decision tree application to satellite measurement and analysis of exospheric neutral densities
… into the role of neutral constituents of Earth’s exosphere in the overall magnetosphere dynamics.
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Remote sensing of ion-neutral charge exchange and diffusive transport in planetary atmospheres
… and H+ flux φH+, in Earth’s thermosphere and exosphere, using empirical constraints on H+ mass conservation (continuity) driven by the reactions between H+, O, O+ and H. The resulting estimates of [H] and φH+ enable the investigation of diurnal variability of the ionosphere and plasmasphere, …
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A Remote Observatory for Geocoronal Hydrogen Emissions
… of the terrestrial upper thermosphere and exosphere, collectively known as the geocorona. This instrumentation is designed to be deployable to a clear-air site, necessitating remote operations of the entire observatory, including control and monitoring. The facility currently employs a …
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The noble gas record of terrestrial and meteoritic samples
… that atmospheric neon has escaped from the exosphere.</li> </ol> <p>A study of noble gases in an Hawaiian xenolith, a deep-seated magnesium silicate with inclusions of liquid CO<sub>2</sub>, provided the following information on the interior of the Earth:</p> <ol> <li>An excess of …