Numerical Study of Baroclinic Wave Dynamics and Plume Behavior in Rotating Rectangular Annulus
Researchers used computational fluid dynamics simulations to study how rotating fluids with temperature gradients generate baroclinic waves and heated plumes in a rectangular annulus geometry. The study examined how two key parameters—Richardson number (measuring plume strength) and Rossby number (measuring rotation effects)—control wave modes and plume structure. The findings help explain fundamental fluid dynamics processes relevant to atmospheric and oceanic circulation patterns.
This numerical study investigates baroclinic wave dynamics in a rotating rectangular annulus with a cooled inner wall and a localized heated plume at the outer bottom, using the OpenFOAM finite-volume solver across multiple parameter combinations. The research identifies geostrophic-hydrostatic balance as the dominant bulk state and demonstrates that baroclinic waves transition from mode m=2 to m=3 as the Rossby number decreases, consistent with theoretical predictions based on the Eady deformation radius. The plume morphology varies significantly with the Richardson number, transitioning from weak, laterally-swept structures at high Richardson numbers to sustained columnar plumes at lower values. The analysis reveals that the plume entrainment coefficient exhibits opposite rotational sensitivities depending on the Richardson number regime, which the authors organize through a local plume Rossby number. A regime map shows that within the explored parameter space, the plume regime and wave-selection problems are approximately separable, with Richardson number controlling plume behavior and Rossby number selecting the dominant baroclinic wave mode.
What's missing
The study's limitations include its restriction to a rectangular annulus geometry (rather than cylindrical), which may not fully capture all aspects of natural rotating systems; the specific parameter ranges explored (Ri₀ = 1–99, Ro = 0.07–0.3) may not encompass all physically relevant regimes; and the applicability of these idealized laboratory-scale simulations to real atmospheric or oceanic systems requires further validation.
What different sources said
- arXiv physicsCenter
Baroclinic wave dynamics in the Ekman-free rotating rectangular annulus with localized forced plume
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