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164 6 Rotational EffectsFig. 6.30 Bathymetry for Exercise 22 (Scenario 2)Two different scenarios are considered. The Coriolis force is ignored in the f rstscenario. Case studies consider variations of bottom drag coefficient The total simulationtime is one day with data outputs at every hour. Because we expect a symmetricshape of the plume, the forcing region is placed in the centre of the otherwiseclosed boundary that cuts along shallower regions of the model domain.The second scenario includes the Coriolis force with f =+1×10 −4 s −1 (northernhemisphere). Again, case studies consider variations of values of the bottom-dragcoefficient The total simulation time is 5 days with one-hourly data outputs. Inanticipation of rotational effects imposed by the Coriolis force, the forcing region ismoved some distance. This is why the forcing region has been moved some distanceupstream, as is shown in Fig. 6.30. The time step is set to Δt = 6 s in all experiments.6.17.3 Write a New Simulation Code?There is no need to formulate a new FORTRAN simulation code for this exercise.Instead, the two-layer of this, the two-layer version of the shallow-water equations,used in Exercises 20 and 21, can be applied with the constraint that the surface layeris at rest.6.17.4 ResultsAs anticipated, the forcing applied creates a gravity current moving denser wateraway from the source. First, we consider the situation without the Coriolis force(Scenario 1). On an even seafloo , the spreading of dense water would be radiallysymmetric. On the other hand, a sloping seafloo supports a net downslope pressuregradientforce, so that, in addition to radial spreading, the plume moves downslope