Predictability in Unstable, Continuous Systems/Predictability and Dynamics of Geophysical Fluid Flows

摘要

Research under this grant focused primarily on computations of unstable nonlinear periodic solutions, time-dependent normal modes (Floquet vectors), and singular vectors in a two-layer quasi-geostrophic channel model. The model was studied in weakly and strongly nonlinear regimes, in which small disturbances to an unstable, steady, zonal, baroclinic shear flow grow to finite amplitude and continue to vacillate irregularly for arbitrarily long times. The computation of time-dependent, normal-mode disturbances to unstable, nonlinear, time-periodic basic flows in a high-dimensional geophysical fluid model opens a new perspective on the analysis of disturbance growth in time- dependent flows, and on the closely related problem of error growth in predictive models of time- dependent flows.