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Updated: Jul 16, 2026
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Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel
Published on: October 5, 2018
Baroclinic waves in an air-filled thermally driven rotating annulus
1Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom.
Summary
This study explored baroclinic waves in air within a rotating annulus, revealing new flow regimes and transitions. The findings contrast with previous liquid experiments, showing no hysteresis in flow type.
Area of Science:
- Fluid dynamics
- Atmospheric science
- Geophysics
Background:
- Baroclinic instability is a key driver of weather systems.
- Previous research primarily used high Prandtl number liquids, leaving air's behavior unexplored.
- Understanding these waves is crucial for climate and atmospheric modeling.
Purpose of the Study:
- To experimentally investigate baroclinic waves in air.
- To explore a previously uncharted parameter space for baroclinic instability.
- To compare air's flow regimes with those of liquids.
Main Methods:
- Utilized a differentially heated rotating annulus with air.
- Varied parameters to identify different flow regimes.
- Mapped flow regime distribution in a parameter space diagram.
Main Results:
- Observed steady waves, periodic and modulated amplitude vacillations, and weak waves.
- Identified a regime diagram for air's baroclinic instability.
- Found transitions between regimes occurred in the opposite sense to high Prandtl number liquids.
Conclusions:
- Air exhibits unique baroclinic wave behaviors in the studied parameter space.
- Experimental results align with some numerical predictions.
- No hysteresis was observed with respect to rotation rate variations.
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