43 
7 Model simulations as part of the project 
The BSH model system comprises three models. A two-dimensional, barotropic model of the 
North-East Atlantic Ocean computes the boundary conditions for a three-dimensional 
baroclinic model of the North and Baltic Seas, especially to account for the occurrence of 
external surges. A higher-resolution model of the German Bight and western Baltic Sea is 
interactively nested into the latter model (Dick et al. 2001). Additionally, a two-dimensional 
barotropic model of the North Sea (North Sea 10 km) is available for fast forecasts of storm 
surges (Müller-Navarra et al. 2003). These models solve hydrostatic non-linear shallow water 
equations taking into account variable bottom topography and bottom friction. 
O' 
s E 
id'E 
bo'N 
M N 
E3'N 
so N 
w N 
o' a'E io E 
Hirtsholm 
Aberdeen 
North Shields 
& 
Cuxhavei 
Borkum 
■Immingham 
Ijmuiden 
■we stoft. 
a SO 1 CO 13D 2 CO 230 2CO 350 400 
Fig. 7.0.1: Bathymetry of the BSH's "North Sea 2 km" model. 
As has been pointed out under 5 above, the model equations of the North and Baltic Sea 
model are suitable, in principle, for modelling the propagation and modification of tsunami on 
the shelf. In contrast, the North-East Atlantic model has only limited suitability for computing 
tsunami propagation in the deep ocean and its modification on the continental slope. 
Adequate simulation of tsunami in the North Sea, therefore, first of all requires a profound