Accession Number : ADA182228

Title :   The Stability of Atmospheric Fields Induced by Localized Topography and Heat Sources.

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

Corporate Author : TECHNION - ISRAEL INST OF TECH HAIFA DEPT OF MATHEMATICS

Personal Author(s) : Merkine,Lee-Or

Report Date : 31 MAR 1987

Pagination or Media Count : 77

Abstract : In slightly viscous rotating stratified systems weak potential vorticity sources can excite finite amplitude response when the group velocity of the long waves vanishes. This mechanism is used, in a two layer fluid, to generate steady state solutions that can be characterized as currents. The currents are strongly sheared in both the vertical and the meridional directions but they vary slowly in the zonal direction. Numerical simulations reveal that the currents are unstable with respect to small perturbations and that the unstable response is dominated by trapped eigenmodes. A WKB analysis jointly with a second order turning point problem are used to derive a consistent description of the spatial and temporal characteristics of the unstable eigenmodes. The stability analysis is applicable to zonally varying basic states that are stationary with respect to zonal variations at some isolated points of the flow domain.

Descriptors :   *TOPOGRAPHY, *ATMOSPHERIC MOTION, *CONVECTION(HEAT TRANSFER), *CONVECTION(ATMOSPHERIC), CONSISTENCY, FLOW, HEAT, SOURCES, LONG WAVELENGTHS, PERTURBATIONS, SOLUTIONS(GENERAL), STEADY STATE, FLUIDS, LAYERS, AMPLITUDE, RESPONSE, VELOCITY, NUMERICAL ANALYSIS, STABILITY, EIGENVECTORS, POTENTIAL FLOW, VORTICES

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE