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.
Results
Showing 1 to 20 of 86 for “"gravity wave"”.
-
Nonlinear gravity wave-wind interactions and jet stream gravity wave generation.
Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.
-
The gravity wave-critical level interaction
… are developed to examine various features of the gravity wave-critical level interaction and some of its possible roles in the dynamics of the atmosphere and the oceans. A linear inviscid steady state model is designed which, though singular at the critical level, illustrates certain important …
-
Oblique reflections of internal gravity wave beams
… nonlinear effects in reflections of internal gravity wave beams in a continuously stratified liquid which are incident upon a uniform slope at an oblique angle. Wave motion in a stratified fluid medium is unique in the sense that the anisotropy of stratification directs energy transport in a …
-
Parametric subharmonic instability of internal gravity wave beams
Internal gravity wave beams are time-harmonic plane waves with general spatial pro- le that arise in continuously stratified fluids owing to the anisotropy of this wave motion. In the last decade, these wave disturbances have been at the forefront of research, both from a fundamental perspective …
-
Gravity Wave and Turbulence Transport in the Mesopause Region
<p>Vertical transport due to dissipating gravity waves and turbulence in the mesopause region (85-100 km) are analyzed with observational data obtained from a narrow-band sodium wind/temperature lidar located at Andes Lidar Observatory (ALO), Cerro Pach´on (30.25 S, 70.73 W), Chile. The Na lidar at …
-
Orographic Gravity Wave Drag and the Large Scale Atmospheric Circulation
… circulation, which is affected by orographic gravity waves and the drag force that they exert on the mean flow. The effects of Orographic Gravity Wave Drag (OGWD) are what is explored in this thesis. By experimenting on the OGWD forcing in an idealized General Circulation Model. Firstly, the …
-
Dynamics of Atmospheric Gravity Wave Breaking in the Mesopause Region
… the understanding of the dynamic process of wave breaking and their effects in the mesopause region above Andes Lidar Observatory (30.2◦ S, 70.7◦ W). A few scientific topics related to GW break- ing are addressed. What are the probabilities of the atmosphere becoming convectively or …
-
A statistical climatology of mesospheric gravity wave activity over Urbana
… are dominated by a spectrum of propagating gravity waves. An alternative approach, time-domain-interferometry (TDI), to estimating the vector winds using the measured radial velocity and angle-of-arrival of the scattered signal is investigated and extended to the estimation of wind variances …
-
Triadic Resonance Instability in finite-width internal gravity wave beams
… the weakly non-linear dynamics of an internal wave beam becoming unstable to Triadic Resonance Instability (TRI). To date, most theoretical work examines the instability in the context of monochromatic plane waves. In the ocean, however, waves seldom take this form, rather they manifest as …
-
Theoretical and experimental study of nonlinear internal gravity wave beams
… the atmosphere and the oceans, support internal gravity waves due to the effect of buoyancy. This type of wave motion is anisotropic since gravity provides a preferred direction. As a result, a localized source oscillating at a frequency below the buoyancy frequency in a uniformly stratified …
-
Investigation of a gravity wave ducting event in the upper mesosphere
Atmospheric gravity waves (GWs) play an important role in the transport of energy and momentum throughout the Earth’s atmosphere. GW effects couple the lower regions of the atmosphere with the middle and upper regions of the atmosphere and the neutral atmosphere with the ionosphere. The effects are …
-
Gravity wave signals from relativistic calculations of binary neutron star coalescence
… code used to study the gravitational wave signature produced by coalescing neutron star binary systems. Additionally, we have studied the properties of remnants which may be formed during the merger process. We have introduced a hybrid post-Newtonian formalism, which treats lowest …
-
Role of Planetary Wave-Tide-Gravity Wave Interactions In Whole Atmosphere Coupling
… sites and compared to a co-located sodium lidar. Wave-wave interactions in the mesosphere and lower thermosphere (MLT) that may be responsible for the penetration of six-day periodicities into the Earth's ionosphere during the 2019 Southern Hemispheric (SH) SSW are first investigated. This study …
-
Fabry-Perot Observations of Midlatitude Neutral Winds and Atmospheric Gravity Wave Activity
… is modulated by a number of atmospheric waves propagating upward from various sources in the lower atmosphere. Among these are atmospheric gravity waves which have been recognized as a major source of momentum and energy in the mesosphere and lower thermosphere as well as a major factor …
-
Middle Atmosphere Structure and Dynamics: Lidar Studies and Gravity Wave Spectral Modeling
Finally, a new gravity wave spectral model is developed. We employ more realistic models of the source spectra and diffusive filtering theory (DFT) to model the one-dimensional and two-dimensional spectra of horizontal and vertical winds, atmospheric density, and temperature. Although more …
-
Gravity Wave/large-Scale Flow Interactions: A Comparison of Model Predication and Observation
… signatures predicted by three commonly used gravity-wave parameterizations: critical level filtering, linear saturation filtering, and diffusive filtering. A one-dimensional, time-independent model filters various gravity-wave spectra using the criteria for each of these parameterizations. …
-
Acoustic-Gravity Wave Propagation Based on Solutions to the Generalized Multi-component Transport Equations
… have provided important insight into acoustic waves generated by natural and man-made hazards, which may steepen into shocks or N-waves while also dissipating when propagating in the thermosphere. Although models have yielded results that agree with observations of ionospheric perturbations, …
-
Gravity Wave Characteristics in the Troposphere, Lower Stratosphere, and Mesopause at the South Pole
… measurements to examine the characteristics of gravity waves at the South Pole. Studies examine the troposphere, lower-stratosphere, and mesopause. It is found that wave strength in the lower atmosphere is always less energetic than at low- and midlatitude sites. In austral winter, wave …
Page 1 of 5