Accession Number : ADA193367

Title :   An Investigation of Atmospheric Dynamics through Their Effects on Mesospheric Optical Emission.

Descriptive Note : Final rept. 1 Sep 83-28 Feb 87,

Corporate Author : CINCINNATI UNIV OH DEPT OF PHYSICS

Personal Author(s) : Tuan, Tai-Fu

PDF Url : ADA193367

Report Date : 23 Mar 1987

Pagination or Media Count : 100

Abstract : Research is described on various aspects of the dynamics of atmospheric gravity waves and their effect on mesospheric airglow emissions, in particular hydroxyl emission. Simultaneous observations of mesospheric optical emissions obtained during the MAPSTAR campaign are analyzed using maximum energy spectral analysis and other methods. The velocity field profiles extracted from this data are compared with gravity wave models based on a realistic nonisothermal background atmosphere. This work enables one to make direct comparisons between airflow data and radar determined wind profiles. A program aimed at investigating small temporal and spatial scale airflow fluctuations is outlined, and the simultaneous ducting and filtering of short period gravity waves by an atmosphere with a nonisothermal temperature profile is modeled theoretically. It is shown that waves from lower-atmospheric or terrestrial sources with group velocity upward are reflected at the altitude where the wave frequency becomes equal to the local Brunt Vaisala frequency. This filters out the shorter period waves, preventing them from reaching higher altitudes and, in conjunction with the ground boundary condition, results in a set of fully guided modes, whose frequency dispersion is investigated.

Descriptors :   *AIRGLOW, *GRAVITY WAVES, *MESOSPHERE, ALTITUDE, EARTH ATMOSPHERE, BACKGROUND, BOUNDARIES, DISPERSING, DUCTS, DYNAMICS, EARTH(PLANET), EMISSION, ENERGY, FREQUENCY, GROUND LEVEL, HIGH ALTITUDE, OPTICAL PROPERTIES, PROFILES, RADAR, REFLECTION, SHORT RANGE(TIME), SOURCES, SPECTRUM ANALYSIS, SYNCHRONISM, ATMOSPHERIC TEMPERATURE, VELOCITY, WAVE PROPAGATION, WIND, OPTICAL DATA, ATMOSPHERE MODELS, SPATIAL DISTRIBUTION, HYDROXYL RADICALS, PHASE, CORRELATION, SCATTERING

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE