Professor Hart will carry out numerical and theoretical modeling, as well as further laboratory experiments, on the transition between various ordered and chaotic states in a two- layer baroclinic rotating fluid. The numerical modeling will address the extensive laboratory data sets on transitions between steady, periodic, and chaotic (aperiodic) types of motion arising from baroclinic instability on the f-plane, as well as on the polar B-plane. Of particular interest is the role of the rigid sidewall boundary condition in the transition process. Its presence leads to a horizontal shear of the basic flow, a modification to the basic eigenfunctions of the linear free-slip problem, and the possibility of flow separation. Theoretical and experimental studies will focus on the processes that may destabilize the simple steady and vacillatory regimes that are observed in laboratory experiments, and which are successfully predicted by low-order (and/or weakly nonlinear) quasi-geostrophic theory. In addition to the role of the viscous sidewall, two potentially destabilizing mechanisms of interest in atmospheric and ocean sciences are periodic and topographic forcing. The action of these physical effects on the B-plane finite-amplitude baroclinic instability problem will be investigated through the use of laboratory and numerical models.//
