Abstract
The behavior of baroclinic waves in a skewed basic field due to a simple shaped orography was investigated through laboratory experiments using a rotating annulus of fluid.
Investigation was made of the transition from an upper symmetric to a wave regime. Examination was conducted of the heat flux, the structure of stationary vortices and baroclinic waves along with the time-dependent behavior of the baroclinic waves. For a given zonal wavenumber the transition to a wave regime occurred at a lower thermal Rossby number in the skewed field than in the axisymmetric field. This exhibits the stabilizing effect of the orography, which is consistent with the results of Jonas (1981). The structure of baroclinic waves showed a dependence on the zonal direction, that is, amplification occurred on the lee side of the obstacle, confirming the results of linear theory by Niehaus (1980).
