Abstract
Characteristics of baroclinic waves in a differentially heated rotating fluid annulus are studied experimentally over a wide range of angular speed. The annulus geometry is properly selected to produce unmodulated waves so that tilted-trough vacillation with a definite period and high rotational symmetry comparable to steady wave and amplitude vacillation is obtained. Its characteristics (vacillation period, drift period and frequency spectra) are examined in detail. Time variations of the top-surface velocity fields and the horizontal temperature fields in an upper layer during a cycle of tilted-trough vacillation are described ; the temperature fields were constructed indirectly from data obtained with a small number of probes to reduce probe effects. The dependence of the rates of radial heat transport on the angular speed and the dominant wavenumber is also presented.
