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Hello,

I'm new to oceanic modeling and I'm currently working on a Telemac 3D model of the Strait of Gibraltar. For the open boundary conditions, I'm using TPXO data to set water levels and velocities. Is there an alternative method to specify boundary velocities, like from an external data source? My concern is that using only tidal velocities might not be sufficient for my case, especially given the complex hydrodynamics in my domain. This approach seems to yield unrealistic velocity results.

Am I overlooking something, or could this be related to my setup? I would appreciate any advice or suggestions on how to address this issue.

Thanks!

Hello Rafia,

Can you show the extent of your model please?
Which tidal solution do you use, the TPXO global solution? In that case, which version? If the maritime boundary is included in the Atlantic Ocean regional solution, you can try this other database:
www.tpxo.net/regional

If you have shallows in the tidal solution where you want to interpolate your maritime boundary conditions, you may have issues if water depth is close to 0. In that case, you can play a little bit with 2 keywords for boundary and initial conditions: MINIMUM DEPTH TO COMPUTE TIDAL VELOCITIES BOUNDARY CONDITIONS and MINIMUM DEPTH TO COMPUTE TIDAL VELOCITIES INITIAL CONDITIONS. By default, the values is 10 cm, but you can increase it (e.g. 1 m, even 10 m or more depending on the local bottom elevation). Have a look at the user manual to know more.

If the issue still remains or if you want to try something else, you can try to use HAMTIDE global solution (available since release 8.5). It does not provide circulations (water depth times velocities) but velocities directly. I can provide a link to download the 2 files if needed.

You can also use other tidal database as FES if you can generate an harmonic constant file.

Hope this helps,

Chi-Tuan