I investigate the effects of varying the stratification parameters of one and two layer quasigeostrophic models on the wind driven ocean circulation. The double-gyre wind-driven ocean circulation has been widely studied in an attempt to understand the internal variability present in the ocean. In recent years, the machinery of dynamical systems theory has been applied to the problem, and has met with considerable success in diagnosing some of the variability in simple layer models. However, the sensitivity of these models to the shape and strength of the ocean stratification has been largely ignored. This study is an effort to address this lack of attention. Using the results of a barotropic quasigeostrophic model as a baseline case, the sensitivity of a reduced gravity quasigeostrophic model to the strength of stratification, and the sensitivity of a two-layer quasigeostrophic model to the strength and shape of stratification are explored.; The effects of stratification strength vary slightly between the reduced gravity and two-layer models. In both models, weaker stratification leads to longer timescales and more regular oscillations, and shifts the parameter ranges in which steady, periodic, and aperiodic states appear. If the dissipation takes the form ∇2q, rather than ∇4psi, the stratification strength also has effects related to the strength of the interfacial friction. In the reduced gravity model, this additional friction term serves to extract energy from the system, while in the two layer model, it transfers energy between the layers.; The two layer model also has a parameter describing the shape of the stratification. This parameter, the layer thickness ratio delta, affects the balance of the forcing on the barotropic and baroclinic modes of the system, as well as affecting the relative scaling of the nonlinear interactions between those modes. A deeper upper layer leads to increased variability, regardless of whether one holds the forcing on the barotropic or baroclinic mode fixed.
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