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 Title: Gravity Waves Studies in Mesopause Region by Using Na Wind/temperature Lidar Author(s): Yang, Weimin Doctoral Committee Chair(s): Gardner, Chester S. Department / Program: Electrical Engineering Discipline: Electrical Engineering Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Engineering, Electronics and Electrical Abstract: University of Illinois Na wind/temperature lidar was installed at the Starfire Optical Range (SOR) (35$\sp\circ$N, 106.5$\sp\circ$W) near Albuquerque, New Mexico, in September 1994. The Na wind/temperature lidar system was interfaced with a 3.5-m diameter fully steerable telescope to provide the direct measurements of Na density, atmosphere temperature, and all three wind components. The laser tuning technique is improved. To make the lidar capable of measuring horizontal wind, the mirror mounting is integrated into the lidar system, and software is written to control the mirror mounting and to communicate with the telescope computer. Eight night observations were conducted on November 1994, February 1995 and April 1995. The Starfire observations yielded high-resolution and high-quality data sets. Lidar measurements of the mesospheric Na layer at the Starfire are used to study heat flux and cooling rate over mesopause region by directly measuring vertical wind and temperature. The various error sources are analyzed. The heat flux and cooling rate show considerable variability. The measured heat flux and cooling rate are consistent with theoretical predictions. These measurements are also used to characterize the monochromatic gravity waves and to explore the relationships among monochromatic gravity wave parameters. A new hodograph analysis technique is developed. All parameters of monochromatic gravity waves are computed. The distinct feature of this study is that all gravity waves parameters are measured directly. Results are consistent with previous studies. The systematic relationship between monochromatic wave amplitudes and wavelengths are contradicted with prediction of linear instability theory. The systematic relationships between the monochromatic gravity wave periods, wavelengths, and amplitudes agree remarkably well with predictions of diffusive filtering theory. This study suggests that the complex nonlinear interaction and evolution of the gravity waves can be modeled successfully as diffusion process. Issue Date: 1998 Type: Text Language: English Description: 116 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1998. URI: http://hdl.handle.net/2142/81255 Other Identifier(s): (MiAaPQ)AAI9904630 Date Available in IDEALS: 2015-09-25 Date Deposited: 1998
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