GENERALIZED STABILITY THEORY .1. AUTONOMOUS OPERATORS

Classical stability theory is extended to include transient growth pro cesses. The central role of the nonnormality of the linearized dynamic al system in the stability problem is emphasized, and a generalized st ability theory is constructed that is applicable to the transient as w ell as the asymptotic stability of time-independent flows. Simple dyna mical systems are used as examples including an illustrative nonnormal two-dimensional operator, the Eady model of baroclinic instability, a nd a model of convective instability in baroclinic flow.