Date of Award

6-2011

Document Type

Thesis - Open Access

Degree Name

Master of Science in Engineering Physics

Department

Physical Sciences

Committee Chair

Dr. John M. Hughes

First Committee Member

Dr. Gulamabas Sivjee

Second Committee Member

Dr. Alan Lui

Abstract

The mesosphere and lower thermosphere displays a wide range of dynamical phenomena resulting in a complex and variable regions. Governed primarily by fluid dynamics, the motion of the upper atmosphere 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 in the dynamic coupling between the troposphere and lower thermosphere. A Fabry-Perot interferometer possessed by the Space Physics Research Laboratory at the Embry-Riddle Aeronautical University, Daytona Beach, FL campus was used to measure Doppler shifts in the atomic oxygen green line emission which originates from an altitude of 96 km. The process of extracting the horizontal winds from the detected Doppler shifts and the resulting time series of the zonal and meridional winds at that altitude is presented. The winds at various nights as well as the average winds for two months were compared with the Horizontal Wind Model 07. Fourier analysis was performed on the time series to determine intrinsic periodicities of the calculated winds. The spectral power of three different nights, each with different weather to the west of Daytona Beach is also presented. Each spectrum depicted the shorter period harmonics of the semi-diurnal tide. Gravity wave activity was correlated to a thunderstorm on the west coast of Florida for one night. The peak of the recorded gravity wave had an observed frequency of 1.663 hr^-1 and an intrinsic frequency of 0.0622 hr^-1. The wave’s direction of propagation was in agreement with the direction of the observed winds at the time of the wave’s peak.

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