Planetary Climate Dynamics

Abstract:

The dataset is documented in readme.pdf. The data files are in uncompressed .tar format. This dataset contains 11 1/2 hours of horizontal velocity measurements from four experiments using AOPP's 'small annulus' thermally-driven rotating annulus laboratory experiment. The experiments cover regular (2S, 3AV) and weakly chaotic (3SV) flow regimes. The apparatus consists of two concentric right circular cylinders with height 14.0cm and radii 2.5cm and 8.0cm, with a 17% glycerol / 83% water mixture (by volume) between them. The outer cylinder is heated and the inner cylinder cooled relative to the working fluid, with a temperature difference of approximately 4K, and the apparatus rotates about the co-incident axis of the two cylinders at rates between 0.75 and 3.1 rad/s. This setup mimics the main effects acting on a planetary atmosphere: gravity, rotation, and a heating gradient between low and high latitudes.

Abstract:

This chapter focuses on the "classical" thermally driven, rotating annulus system. It reviews the current state of understanding of the rich and diverse range of flow regimes that may be exhibited in thermal annulus experiments from the viewpoint of experimental observation, numerical simulation, and fundamental theory. This includes interpretation of various empirical experimental observations in relation to both linear and weakly nonlinear baroclinic instability theory. The chapter then examines how heat is transported within the baroclinic annulus across the full range of control parameters, associated with both the boundary layer circulation and baroclinically unstable eddies. It considers the overall role of annulus experiments in the laboratory in continuing to advance understanding of the global circulation of planetary atmospheres and oceans, reviewing the current state of research on delineating circulation regimes obtained in large-scale circulation models in direct comparison with the sequences of flow regimes and transitions in the laboratory.