Baroclinic adjustment

Moreover, the Kelvin wave can control the water exchange between two basins connected by a channel. The basic physics of this process can be reduced to the Rossby adjustment process in a channel of uniform depth and uniform width. This problem was considered theoretically by Gill (1976) as an initial problem with a steplike sea level distribution in the channel. The results are similar for abarotropic and a baroclinic two-layer flow however, the sea level elevation must be replaced by the elevation of the interface and the barotropic long wave phase velocity by the baroclinic phase velocity, which is much smaller than the barotropic velocity. This implies that the baroclinic Rossby radius is more than one order of magnitude smaller than the barotropic radius. 

A critical issue is the proper choice of the horizontal and vertical model resolution. The baroclinic Rossby Radius is a typical horizontal scale for eddies and wavelike processes. If this scale, that varies in the Baltic from less than 1 km to 7 km (Fennel et al., 1991), is not resolved, adjustment processes by waves are filtered out and the model dynamics is... 

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