The youtube movie below shows Log10 dye concentration (no units) at New River Inlet released just up the inlet over t=2-4 hr.    This simulation is forced by the M2 tide and has no stratification, no wind, and no waves.  Top: time series of tidal elevation at (x,y)=(0,0) m.   The red dashed line represents the current time location.    Bottom:  plan view of Log10 surface dye concentration.   Only a subset of the model domain is shown.   Land values are white and dashed lines represent bathymetry contours (2, 4, 6, 8, 10, 12 m depth).    The colorbar gives log10 concentration: Check the video below:

I also looked at the bottom dye concentration.   Although there are subtle differences the movies look pretty much the same.   For these purposes this unstratified simulation is pretty well-mixed.

At first release, the dye jets about 2 km offshore of the inlet mouth.    There is a significant amount of dye flux back into the inlet.    However, this may be a result of no wind, no waves, no  alongshore tidal propagation, and no other shelf-scale forcing mechanisms that drive shelf-scale alongshore currents.

If folks are interested in the .mp4 video file (better resolution) it can be downloaded via NRI_dye_surface_delft3d

Please feel free to leave comments and suggestions.   -falk