The Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO) are the most pronounced modes of extratropical atmospheric wintertime variability in the Northern Hemisphere. This thesis investigates different aspects of the AO and NAO on the in traseasonal and seasonal time scales. First, the question of how the differences between the AO and NAO are influenced by the choice of the definitions of the NAO and to what extent the AO and NAO differ from each other is investigated using the daily NCEP/NCAR reanalysis data spanning 51 boreal winters. One AO index and four different NAO indices are used in this study. It is found that the AO and NAO are quite similar to each other when both are defined using pattern-based indices, while some notable differences are observed between them when the NAO is defined using a station/gridpoint-based index. Then the predictability of the AO and NAO is examined using a simple general circulation model (SGCM). Numerical experiments are performed to determine the sensitivity of the setup processes of the AO and NAO to the details of the initial conditions. The predictive skills for the AO and NAO are compared to each other. Finally, the potential role of tropical Pacific forcing in driving the seasonal variability of the AO is explored using both observations and the SGCM. The results indicate that a negative thermal forcing over the western tropical Pacific and a positive forcing north of the equatorial mid-Pacific play important roles in producing an AO-like atmospheric response.

Restoration of realistic animation is a critical part in the area of computer graphics. The goal of this sort of simulation is to imitate the behavior of the transformation in real life to the greatest extent. Physics-based simulation provides a solid background and proficient theories that can be applied in the simulation. In this dissertation, I will present real-time simulations which are physics-based in the area of terrain deformation and ship oscillations. When ground vehicles navigate on soft terrains such as sand, snow and mud, they often leave distinctive tracks. The realistic simulation of such vehicle-terrain interaction is important for ground based visual simulations and many video games. However, the existing research in terrain deformation has not addressed this issue effectively. In this dissertation, I present a new terrain deformation algorithm for simulating vehicle-terrain interaction in real time. The algorithm is based on the classic terramechanics theories, and calculates terrain deformation according to the vehicle load, velocity, tire size, and soil concentration. As a result, this algorithm can simulate different vehicle tracks on different types of terrains with different vehicle properties. I demonstrate my algorithm by vehicle tracks on soft terrain. In the field of ship oscillation simulation, I propose a new method for simulating ship motions in waves. Although there have been plenty of previous work on physics based fluid-solid simulation, most of these methods are not suitable for real-time applications. In particular, few methods are designed specifically for simulating ship motion in waves. My method is based on physics theories of ship motion, but with necessary simplifications to ensure real-time performance. My results show that this method is well suited to simulate sophisticated ship motions in real time applications.

A study of ion oscillations in the annular regions of a strontium plasma is reported. An ultracold neutral plasma is formed by photoionizing the 1 P 1 electrons using a pulsed dye laser' and absorption spectroscopy is done on the 2 S ½ - 2 P ½ transition of the Sr+ ion. The kinetic energy of the ions is then calculated using Doppler broadening of the spectrum. The variation of temperature with time is fit to a theoretical model of kinetic energy oscillation. The result of the fitting is presented in this thesis. The importance of an annular analysis of the absorption spectrum is demonstrated and the mathematical procedures employed to calculate the kinetic energy are developed. The oscillations are observed to be damped which is a characteristic of strongly coupled plasmas.

The Tokai-to-Kamioka (T2K) experiment is a long-baseline neutrino-oscillation experiment that searches for neutrino oscillations with measurements of an off-axis, high purity, muon neutrino beam. The neutrinos are detected 295 km from production by the Super Kamiokande detector. A near detector 280 m from the production target measures the unoscillated beam. This thesis outlines an analysis using samples in the near detector and Super Kamiokande to measure the disappearance of muon neutrinos. To manage the complexity this analysis, a Markov Chain Monte Carlo framework was used to maximize a likelihood to estimate the oscillation parameters. T2K Run 1+2+3 data (3.010 x10²⁰ POT) is used for the analysis. The estimates for the oscillation parameters are: ( sin² (2θ₂₃ ), Δ m²₃₂ ) = (0.999,2.45 x10ˉ³ [eV²]), and the 90% 1D bayesian credible intervals: 0.9340 < sin² (2θ₂₃ ) < 1.000 2.22 x10ˉ³ < Δm²₃₂ [eV²] < 2.74 x 10ˉ³ / Graduate / 0798

No description available.

Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: Daniel J. Leathers, Dept. of Geography. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xv, 200 p.; also includes graphics. Includes bibliographical references (p. 173-184).

Thesis (M.Sc.). / Written for the Dept. of Atmospheric and Oceanic Sciences. Title from title page of PDF (viewed 2009/06/23). Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1999. / Includes bibliographical references (leaves 137-142).

Thesis (Ph. D.)--University of California, Los Angeles, 1997. / Vita. Includes bibliographical references (leaves 200-208).