Models of planetary wave propagation in the middle atmosphere

Miscellaneous · Mon Jan 01 00:00:00 EST 1990

OSTI ID:5315460

Ma, C

Linear steady-state models were used to study the propagation of quasi-stationary planetary waves through zonally symmetric basic states with both meridional and vertical wind shears. Simulations from a comprehensive general circulation model were analyzed to provide realistic basic state and forcing. A quasi-geostrophic and a primitive-equation model were constructed. The models were found to give very different results when the Rossby number of the mean flow is large (around 0.4). The quasi-geostrophic model tends to give larger amplitude and longer vertical wavelength than the primitive-equation model. The wind shear and curvature of the basic state were found to play dominant roles in determining the refractive properties for wave propagation and wave structures in the upper stratosphere and mesosphere. The polar-night jet acts like a waveguide which allows waves to propagate to high altitudes. The forcing at the lower boundary has a smaller effect on the response away from the lower boundary. The linear response to tropospheric forcing was also found to be sensitive to the method of parameterization of Rayleigh friction near the critical lines. It is less sensitive to the background dissipation and the static stability parameters. When the linear solutions were compared to the planetary waves simulated by the general circulation model, certain discrepancies were found. The linear model can generally reproduce the location of maximum amplitude response and phase structure successfully, but tends to underestimate the wave amplitude. Diagnostic tools such as refractive indices, Eliassen-Palm fluxes and ray tracing techniques were used to study the relationship between the linear response and the basic state. They were found to be complementary in providing a better knowledge of wave propagation.

• Research Organization: Princeton Univ., NJ (United States)
• OSTI ID: 5315460
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH ATMOSPHERE
WAVE PROPAGATION
ALTITUDE
ATMOSPHERIC CIRCULATION
COMPUTERIZED SIMULATION
FRICTION
MATHEMATICAL MODELS
REFRACTIVITY
STABILITY
THEORETICAL DATA
WAVEGUIDES
WIND
DATA
INFORMATION
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SIMULATION
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena