Date of Award:
12-2017
Document Type:
Dissertation
Degree Name:
Doctor of Philosophy (PhD)
Department:
Physics
Committee Chair(s)
Tao Yuan
Committee
Tao Yuan
Committee
Mike Taylor
Committee
Vince Wickwar
Committee
Ludger Scherliess
Committee
Ryan Davidson
Abstract
Gravity waves in the atmosphere are the waves with gravity and buoyancy force as the restoring forces. Gravity waves will significantly impact the Mesosphere Lower / Thermosphere (MLT), and the breaking of gravity waves is the key factor to cause the cool summer and warm winter in the Mesopause region. Therefore, it is important for us to investigate gravity waves. In this dissertation, we mainly use USU Na lidar data to explore gravity waves in the MLT. The exploration is made up of two projects. One is the investigation of gravity wave breaking and the associated dynamic instability by USU Na Lidar and Advanced Mesosphere Temperature Mapper (AMTM). Another is the calculation of gravity wave temperature perturbations and potential energy density by least-squares fitting based on the data from the full-diurnal cycle observation of Na lidar. The sporadic sodium layer is the sharp increase of Na density in a small vertical range (several kilometers) above the Na main layer in the MLT. The formation of the sporadic sodium layer above 100 km remains unknown until now. Here we will investigate the mechanism of the generation of sporadic sodium layer using numeric modeling, including the effect of tide and gravity wave on the variation of Na density.
Checksum
54ae5399910d854159216e4a8e90149c
Recommended Citation
Cai, Xuguang, "The Investigation of Gravity Waves in the Mesosphere / Lower Thermosphere and Their Effect on Sporadic Sodium Layer" (2017). All Graduate Theses and Dissertations, Spring 1920 to Summer 2023. 6891.
https://digitalcommons.usu.edu/etd/6891
Included in
Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .