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 20 of 32 for “"planetary atmospheres"”.
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Infrasound Propagation in Terrestrial Planetary Atmospheres
… acoustic waves in different terrestrial planetary atmospheres. The model, which includes gravity, molecular viscosity, and thermal conduction, has been developed using numerical solutions in Fortran, and is validated for the atmospheric conditions of Earth, Mars, and Venus. Empirical …
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Molecular Spectroscopy: A Study of Molecules in Earth and Planetary Atmospheres
… to occur in cool stellar and sub-stellar atmospheres.</p> <p>A new line list for the A<sup>2</sup>Σ+X<sup>2</sup>Π electronic transition of OH has been calculated. Line positions have been taken from the literature and refitted with Western's PGOPHER program. Line intensities were …
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Remote sensing of ion-neutral charge exchange and diffusive transport in planetary atmospheres
Planetary atmospheres are the envelope of gases that encircle a planet. This region is constantly interacting with energy and particles from the Sun and exhibits variability in its composition, structure, and evolution over periods ranging from hours to years. Through the loss of water to space, …
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A discrete forward-modeling method for characterizing occultation lightcurves of tenuous planetary atmospheres
… lightcurves from stellar occultations by planetary atmospheres. Our discrete approach provides a way to arbitrarily set atmospheric properties at any radius from the occulting body, giving it flexibility for applying models of vertical variation in atmospheric conditions. The method is …
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Observations, Thermochemical Calculations, and Modeling of Exoplanetary Atmospheres
… thermochemical calculations, and modeling their atmospheres. We used Spitzer multi-wavelength secondary-eclipse observations to characterize planetary atmospheres. We chose targets with high signal-to-noise ratios, as their deep eclipses allow us to detect signatures of spectral features and …
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Effects of starspots activity on optical and near infrared observations of planetary transits
… depth determination and the derivations of planetary and stellar parameters. Surface brightness inhomogeneities, such as starspots or bright faculae, on star disc have an intrinsic dependence on wavelength and thus on the stellar colours. The colour dependence of stellar activity may …
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The impacts of atmospheric radiation on studies of planetary habitability
… determining whether these conditions exist on a planetary body is not possible without a detailed understanding of the radiative processes occurring in a planet’s atmosphere. In this work, studies of the radiative flux and transfer within planetary atmospheres are carried out in order to …
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Learning and investigating phenomenological models for active matter
… in part by the complex flow patterns observed in planetary atmospheres, we investigate generalized Navier–Stokes (GNS) equations that couple nonlinear advection with a generic linear instability. This analytically tractable minimal model for fluid flows driven by internal active stresses has …
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Spectral measurements of hydrogen Lyman-alpha in the atmospheres of Venus and Jupiter using a sounding rocket and the Hubble Space Telescope
… and from this emission many properties of planetary atmospheres can be analyzed. Two projects are studying this emission on two planets for two different scientific purposes. On Venus, the Lyman-alpha emission is being studied to measure the deuterium to hydrogen (D/H) ratio of the …
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Equilibration of an atmosphere by geostrophic turbulence
… zonal mean flows can be obtained in planetary atmospheres if external parameters are varied. We argue that changes in the equilibrated mean state over a wide range of simulations can better be understood in terms of a balance between the diabatic forcing and the eddy driven …
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Laboratory Measurements of the Millimeter Wavelength Opacity of Phosphine (PH3) and Ammonia (NH3) Under Simulated Conditions for the Cassini-Saturn Encounter
The molecular compositions of the atmospheres of the giant planets (Jupiter, Saturn, Uranus and Neptune) are fundamental to understanding the processes which formed these planets and the solar system as a whole. Microwave observations of these planets probe regions in their atmospheres from …
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Stellar occultation studies of Saturn's upper atmosphere
… in Saturn's upper atmosphere, as seen in other planetary atmospheres, by analyzing the power spectra of temperature and density data and by studying the temperature lapse rate in the atmosphere. Our analysis is consistent with saturated gravity waves for all data sets, although gravity wave …
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Beyond the speckles: New horizons in high-contrast imaging for exoplanet science
… offers a uniquely powerful way of characterizing planetary atmospheres, surface conditions, and potential biological markers beyond our solar system. However, the extreme contrast and small angular separations involved present significant observational challenges that demand continual innovation …
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Non-LTE diagnostics of the infrared observations of the planetary atmosphere
… for a mixture of radiating molecular gases in a planetary atmosphere. The approach for the solution of this problem suggested here utilizes the Accelerated Lambda Iteration (ALI) technique developed in stellar astrophysics for spectrum formation calculations and for the computation of non-LTE …
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Magnetoshell Aerocapture: Advances Toward Concept Feasibility
… that proposes to use drag on a dipole plasma in planetary atmospheres as an orbit insertion technique. It aims to augment the benefits of traditional aerocapture by trapping particles over a much larger area than physical structures can reach. This enables aerocapture at higher altitudes, greatly …
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The Atmospheric Fingerprints of Volcanism: Simulating Volcanic Outgassing and Secondary Atmospheres on Rocky Planets
… composition and evolution of rocky planet atmospheres is key to understanding both the conditions required to develop a habitable planet, and to analyse the link between the deep interior and atmosphere of rocky bodies. This thesis uses volcanism as a chemical link between the mantle of a …
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Measurement and characterization of low volatility organic compounds in the atmosphere
… to secondary organic aerosol (SOA) in urban atmospheres. IVOCs are predominately emitted during cold start periods, but maintain a similar chemical composition across all engine states. As emissions controls have tightened, emissions of non-methane hydrocarbons and primary particulate matter …
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Theoretical Prediction of Electronically Excited States and Vibrational Frequencies of Interstellar and Planetary Radicals, Anions, and Cations
… in the interstellar medium and extraterrestrial planetary atmospheres, theoretical methods continue to be an invaluable tool to astronomically minded chemists. Using state-of-the art methods, this doctoral work characterizes the electronically excited states of interstellar radicals, cations, and …
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Zonal flow driven by convection and convection driven by internal heating
… as an idealization of zonal flows in tokamaks, planetary atmospheres, and annular cylindrical convection experiments. These systems often satisfy free-slip conditions on at least one boundary and are approximately two-dimensional. Stable steady states with zonal flow are found for Prandtl …
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