Abstract
In a rotating fluid annulus subjected to a horizontal temperature difference, near the transition point from the (upper) Hadley regime to the Rossby regime, waves with smaller amplitudes than those of the main baroclinic waves are observed on the temperature records.
The periods of the temperature oscillations due to these waves are longer than those due to inertial oscillations and shorter than those due to the baroclinic waves. These new waves have their maximum amplitude near the central region of the fluid layer. Furthermore, even when these waves are detected on the temperature records, the surface flow is axially symmetric so far as it is observed by eye-measurements. These results suggest that the new waves may belong to a different category from the main baroclinic waves.
