Theories of multiple equilibria and weather regimes - a critical reexamination. Part II: baroclinic two-layer models

Abstract

Our result shows that multiple equilibria/weather regimes that are present in lower order models examined disappear when a sufficient number of modes are kept in the spectral expansion of the solution of the governing partial differential equations. Much of the chaotic behavior of the large-scale flow that is present in intermediate order models is now found to be spurious. Physical reasons for the drastic modification are offered. We further note a peculiarity in the formulation of most existing two-layer models that also tends to exaggerate the importance of baroclinic processes and increases the degree of unpredictability of the large-scale flow. -from Authors