Accession Number:

ADA273437

Title:

Nonlinear Dynamics Applied to Atmospheric Prediction

Descriptive Note:

Annual rept. 15 Sep 93-14 Oct 93,

Corporate Author:

FLORIDA STATE UNIV TALLAHASSEE GEOPHYSICAL FLUID DYNAMICS INST

Personal Author(s):

Report Date:

1993-10-14

Pagination or Media Count:

26.0

Abstract:

Under AFOSR grant F49620-92-J-0498, Drs Barcilon and Nathan are studying the impact of steady, zonally varying vorticity forcing on topographic instability and finite amplitude, low frequency oscillations. The model consists of a viscous, barotropic fluid on a zonally periodic, midlatitude B-plane channel, bounded above by a flat, rigid boundary, below by a bottom topography, and laterally by sidewalls at y o,TT Topographically induced low frequency oscillations in the presence of a steady, zonally varying vorticity source have been studied. The source has been shown to interact with the pertubation field to produce zonally rectified wave fluxes that change the zonal momentum balance of the system. This change provides a mechanism for coupling the topographic and vorticity forcings, leading to a dramatic alteration in the Hopf bifurcation from stationary to low frequency, finite amplitude oscillation.

Subject Categories:

  • Atmospheric Physics
  • Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE