Solitary Rossby waves in a two-layer system

Abstract

The solutions for solitary Rossby waves with no critical level in a two-layer system which contains a zonal, baroclinic, mean shear flow are presented. When the mean shear flow has a barotropic structure, these solutions agree with those of Redekopp (1977) in the sense that the barotropic mode obeys the Korteweg-deVries equation, whereas the baroclinic mode obeys the modified Korteweg-deVries equation. It is found that the presence of vertical shear in the mean flow generally tends to steepen the solitary Rossby waves, but the tendency depends strongly on the particular wave mode and the magnitude of the internal rotational Froude number characterizing the wave field.