On the hydrographic response to transient meteorological disturbances

The response to transient forcing in a hydrographic system like the Baltic is considered. We find that under quite general conditions the baroclinic response is confined to a narrow coastal region while the response in the main part of the basin is essentially barotropic. The response is analysed quantitatively under somewhat more stringent conditions using a boundary layer type approach. We find that the barotropic large scale low frequency motions follow contours of constant depth, a feature which might be accessible to empirical verification. The baroclinic coastal response is found to be confined to a region of width 5–10 km (in the Baltic). If the dissipation is sufficiently weak, internal Kelvin waves travelling in a counter clockwise direction may be excited in the coastal region.